Pull cgroup updates from Tejun Heo:
"The cgroup core saw several significant updates this cycle:
- percpu_rwsem for threadgroup locking is reinstated. This was
temporarily dropped due to down_write latency issues. Oleg's
rework of percpu_rwsem which is scheduled to be merged in this
merge window resolves the issue.
- On the v2 hierarchy, when controllers are enabled and disabled, all
operations are atomic and can fail and revert cleanly. This allows
->can_attach() failure which is necessary for cpu RT slices.
- Tasks now stay associated with the original cgroups after exit
until released. This allows tracking resources held by zombies
(e.g. pids) and makes it easy to find out where zombies came from
on the v2 hierarchy. The pids controller was broken before these
changes as zombies escaped the limits; unfortunately, updating this
behavior required too many invasive changes and I don't think it's
a good idea to backport them, so the pids controller on 4.3, the
first version which included the pids controller, will stay broken
at least until I'm sure about the cgroup core changes.
- Optimization of a couple common tests using static_key"
* 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (38 commits)
cgroup: fix race condition around termination check in css_task_iter_next()
blkcg: don't create "io.stat" on the root cgroup
cgroup: drop cgroup__DEVEL__legacy_files_on_dfl
cgroup: replace error handling in cgroup_init() with WARN_ON()s
cgroup: add cgroup_subsys->free() method and use it to fix pids controller
cgroup: keep zombies associated with their original cgroups
cgroup: make css_set_rwsem a spinlock and rename it to css_set_lock
cgroup: don't hold css_set_rwsem across css task iteration
cgroup: reorganize css_task_iter functions
cgroup: factor out css_set_move_task()
cgroup: keep css_set and task lists in chronological order
cgroup: make cgroup_destroy_locked() test cgroup_is_populated()
cgroup: make css_sets pin the associated cgroups
cgroup: relocate cgroup_[try]get/put()
cgroup: move check_for_release() invocation
cgroup: replace cgroup_has_tasks() with cgroup_is_populated()
cgroup: make cgroup->nr_populated count the number of populated css_sets
cgroup: remove an unused parameter from cgroup_task_migrate()
cgroup: fix too early usage of static_branch_disable()
cgroup: make cgroup_update_dfl_csses() migrate all target processes atomically
...
Pull networking updates from David Miller:
Changes of note:
1) Allow to schedule ICMP packets in IPVS, from Alex Gartrell.
2) Provide FIB table ID in ipv4 route dumps just as ipv6 does, from
David Ahern.
3) Allow the user to ask for the statistics to be filtered out of
ipv4/ipv6 address netlink dumps. From Sowmini Varadhan.
4) More work to pass the network namespace context around deep into
various packet path APIs, starting with the netfilter hooks. From
Eric W Biederman.
5) Add layer 2 TX/RX checksum offloading to qeth driver, from Thomas
Richter.
6) Use usec resolution for SYN/ACK RTTs in TCP, from Yuchung Cheng.
7) Support Very High Throughput in wireless MESH code, from Bob
Copeland.
8) Allow setting the ageing_time in switchdev/rocker. From Scott
Feldman.
9) Properly autoload L2TP type modules, from Stephen Hemminger.
10) Fix and enable offload features by default in 8139cp driver, from
David Woodhouse.
11) Support both ipv4 and ipv6 sockets in a single vxlan device, from
Jiri Benc.
12) Fix CWND limiting of thin streams in TCP, from Bendik Rønning
Opstad.
13) Fix IPSEC flowcache overflows on large systems, from Steffen
Klassert.
14) Convert bridging to track VLANs using rhashtable entries rather than
a bitmap. From Nikolay Aleksandrov.
15) Make TCP listener handling completely lockless, this is a major
accomplishment. Incoming request sockets now live in the
established hash table just like any other socket too.
From Eric Dumazet.
15) Provide more bridging attributes to netlink, from Nikolay
Aleksandrov.
16) Use hash based algorithm for ipv4 multipath routing, this was very
long overdue. From Peter Nørlund.
17) Several y2038 cures, mostly avoiding timespec. From Arnd Bergmann.
18) Allow non-root execution of EBPF programs, from Alexei Starovoitov.
19) Support SO_INCOMING_CPU as setsockopt, from Eric Dumazet. This
influences the port binding selection logic used by SO_REUSEPORT.
20) Add ipv6 support to VRF, from David Ahern.
21) Add support for Mellanox Spectrum switch ASIC, from Jiri Pirko.
22) Add rtl8xxxu Realtek wireless driver, from Jes Sorensen.
23) Implement RACK loss recovery in TCP, from Yuchung Cheng.
24) Support multipath routes in MPLS, from Roopa Prabhu.
25) Fix POLLOUT notification for listening sockets in AF_UNIX, from Eric
Dumazet.
26) Add new QED Qlogic river, from Yuval Mintz, Manish Chopra, and
Sudarsana Kalluru.
27) Don't fetch timestamps on AF_UNIX sockets, from Hannes Frederic
Sowa.
28) Support ipv6 geneve tunnels, from John W Linville.
29) Add flood control support to switchdev layer, from Ido Schimmel.
30) Fix CHECKSUM_PARTIAL handling of potentially fragmented frames, from
Hannes Frederic Sowa.
31) Support persistent maps and progs in bpf, from Daniel Borkmann.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1790 commits)
sh_eth: use DMA barriers
switchdev: respect SKIP_EOPNOTSUPP flag in case there is no recursion
net: sched: kill dead code in sch_choke.c
irda: Delete an unnecessary check before the function call "irlmp_unregister_service"
net: dsa: mv88e6xxx: include DSA ports in VLANs
net: dsa: mv88e6xxx: disable SA learning for DSA and CPU ports
net/core: fix for_each_netdev_feature
vlan: Invoke driver vlan hooks only if device is present
arcnet/com20020: add LEDS_CLASS dependency
bpf, verifier: annotate verbose printer with __printf
dp83640: Only wait for timestamps for packets with timestamping enabled.
ptp: Change ptp_class to a proper bitmask
dp83640: Prune rx timestamp list before reading from it
dp83640: Delay scheduled work.
dp83640: Include hash in timestamp/packet matching
ipv6: fix tunnel error handling
net/mlx5e: Fix LSO vlan insertion
net/mlx5e: Re-eanble client vlan TX acceleration
net/mlx5e: Return error in case mlx5e_set_features() fails
net/mlx5e: Don't allow more than max supported channels
...
Pull perf updates from Ingo Molnar:
"Kernel side changes:
- Improve accuracy of perf/sched clock on x86. (Adrian Hunter)
- Intel DS and BTS updates. (Alexander Shishkin)
- Intel cstate PMU support. (Kan Liang)
- Add group read support to perf_event_read(). (Peter Zijlstra)
- Branch call hardware sampling support, implemented on x86 and
PowerPC. (Stephane Eranian)
- Event groups transactional interface enhancements. (Sukadev
Bhattiprolu)
- Enable proper x86/intel/uncore PMU support on multi-segment PCI
systems. (Taku Izumi)
- ... misc fixes and cleanups.
The perf tooling team was very busy again with 200+ commits, the full
diff doesn't fit into lkml size limits. Here's an (incomplete) list
of the tooling highlights:
New features:
- Change the default event used in all tools (record/top): use the
most precise "cycles" hw counter available, i.e. when the user
doesn't specify any event, it will try using cycles:ppp, cycles:pp,
etc and fall back transparently until it finds a working counter.
(Arnaldo Carvalho de Melo)
- Integration of perf with eBPF that, given an eBPF .c source file
(or .o file built for the 'bpf' target with clang), will get it
automatically built, validated and loaded into the kernel via the
sys_bpf syscall, which can then be used and seen using 'perf trace'
and other tools.
(Wang Nan)
Various user interface improvements:
- Automatic pager invocation on long help output. (Namhyung Kim)
- Search for more options when passing args to -h, e.g.: (Arnaldo
Carvalho de Melo)
$ perf report -h interface
Usage: perf report [<options>]
--gtk Use the GTK2 interface
--stdio Use the stdio interface
--tui Use the TUI interface
- Show ordered command line options when -h is used or when an
unknown option is specified. (Arnaldo Carvalho de Melo)
- If options are passed after -h, show just its descriptions, not all
options. (Arnaldo Carvalho de Melo)
- Implement column based horizontal scrolling in the hists browser
(top, report), making it possible to use the TUI for things like
'perf mem report' where there are many more columns than can fit in
a terminal. (Arnaldo Carvalho de Melo)
- Enhance the error reporting of tracepoint event parsing, e.g.:
$ oldperf record -e sched:sched_switc usleep 1
event syntax error: 'sched:sched_switc'
\___ unknown tracepoint
Run 'perf list' for a list of valid events
Now we get the much nicer:
$ perf record -e sched:sched_switc ls
event syntax error: 'sched:sched_switc'
\___ can't access trace events
Error: No permissions to read /sys/kernel/debug/tracing/events/sched/sched_switc
Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'
And after we have those mount point permissions fixed:
$ perf record -e sched:sched_switc ls
event syntax error: 'sched:sched_switc'
\___ unknown tracepoint
Error: File /sys/kernel/debug/tracing/events/sched/sched_switc not found.
Hint: Perhaps this kernel misses some CONFIG_ setting to enable this feature?.
I.e. basically now the event parsing routing uses the strerror_open()
routines introduced by and used in 'perf trace' work. (Jiri Olsa)
- Fail properly when pattern matching fails to find a tracepoint,
i.e. '-e non:existent' was being correctly handled, with a proper
error message about that not being a valid event, but '-e
non:existent*' wasn't, fix it. (Jiri Olsa)
- Do event name substring search as last resort in 'perf list'.
(Arnaldo Carvalho de Melo)
E.g.:
# perf list clock
List of pre-defined events (to be used in -e):
cpu-clock [Software event]
task-clock [Software event]
uncore_cbox_0/clockticks/ [Kernel PMU event]
uncore_cbox_1/clockticks/ [Kernel PMU event]
kvm:kvm_pvclock_update [Tracepoint event]
kvm:kvm_update_master_clock [Tracepoint event]
power:clock_disable [Tracepoint event]
power:clock_enable [Tracepoint event]
power:clock_set_rate [Tracepoint event]
syscalls:sys_enter_clock_adjtime [Tracepoint event]
syscalls:sys_enter_clock_getres [Tracepoint event]
syscalls:sys_enter_clock_gettime [Tracepoint event]
syscalls:sys_enter_clock_nanosleep [Tracepoint event]
syscalls:sys_enter_clock_settime [Tracepoint event]
syscalls:sys_exit_clock_adjtime [Tracepoint event]
syscalls:sys_exit_clock_getres [Tracepoint event]
syscalls:sys_exit_clock_gettime [Tracepoint event]
syscalls:sys_exit_clock_nanosleep [Tracepoint event]
syscalls:sys_exit_clock_settime [Tracepoint event]
Intel PT hardware tracing enhancements:
- Accept a zero --itrace period, meaning "as often as possible". In
the case of Intel PT that is the same as a period of 1 and a unit
of 'instructions' (i.e. --itrace=i1i). (Adrian Hunter)
- Harmonize itrace's synthesized callchains with the existing
--max-stack tool option. (Adrian Hunter)
- Allow time to be displayed in nanoseconds in 'perf script'.
(Adrian Hunter)
- Fix potential infinite loop when handling Intel PT timestamps.
(Adrian Hunter)
- Slighly improve Intel PT debug logging. (Adrian Hunter)
- Warn when AUX data has been lost, just like when processing
PERF_RECORD_LOST. (Adrian Hunter)
- Further document export-to-postgresql.py script. (Adrian Hunter)
- Add option to synthesize branch stack from auxtrace data. (Adrian
Hunter)
Misc notable changes:
- Switch the default callchain output mode to 'graph,0.5,caller', to
make it look like the default for other tools, reducing the
learning curve for people used to 'caller' based viewing. (Arnaldo
Carvalho de Melo)
- various call chain usability enhancements. (Namhyung Kim)
- Introduce the 'P' event modifier, meaning 'max precision level,
please', i.e.:
$ perf record -e cycles:P usleep 1
Is now similar to:
$ perf record usleep 1
Useful, for instance, when specifying multiple events. (Jiri Olsa)
- Add 'socket' sort entry, to sort by the processor socket in 'perf
top' and 'perf report'. (Kan Liang)
- Introduce --socket-filter to 'perf report', for filtering by
processor socket. (Kan Liang)
- Add new "Zoom into Processor Socket" operation in the perf hists
browser, used in 'perf top' and 'perf report'. (Kan Liang)
- Allow probing on kmodules without DWARF. (Masami Hiramatsu)
- Fix 'perf probe -l' for probes added to kernel module functions.
(Masami Hiramatsu)
- Preparatory work for the 'perf stat record' feature that will allow
generating perf.data files with counting data in addition to the
sampling mode we have now (Jiri Olsa)
- Update libtraceevent KVM plugin. (Paolo Bonzini)
- ... plus lots of other enhancements that I failed to list properly,
by: Adrian Hunter, Alexander Shishkin, Andi Kleen, Andrzej Hajda,
Arnaldo Carvalho de Melo, Dima Kogan, Don Zickus, Geliang Tang, He
Kuang, Huaitong Han, Ingo Molnar, Jan Stancek, Jiri Olsa, Kan
Liang, Kirill Tkhai, Masami Hiramatsu, Matt Fleming, Namhyung Kim,
Paolo Bonzini, Peter Zijlstra, Rabin Vincent, Scott Wood, Stephane
Eranian, Sukadev Bhattiprolu, Taku Izumi, Vaishali Thakkar, Wang
Nan, Yang Shi and Yunlong Song"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (260 commits)
perf unwind: Pass symbol source to libunwind
tools build: Fix libiberty feature detection
perf tools: Compile scriptlets to BPF objects when passing '.c' to --event
perf record: Add clang options for compiling BPF scripts
perf bpf: Attach eBPF filter to perf event
perf tools: Make sure fixdep is built before libbpf
perf script: Enable printing of branch stack
perf trace: Add cmd string table to decode sys_bpf first arg
perf bpf: Collect perf_evsel in BPF object files
perf tools: Load eBPF object into kernel
perf tools: Create probe points for BPF programs
perf tools: Enable passing bpf object file to --event
perf ebpf: Add the libbpf glue
perf tools: Make perf depend on libbpf
perf symbols: Fix endless loop in dso__split_kallsyms_for_kcore
perf tools: Enable pre-event inherit setting by config terms
perf symbols: we can now read separate debug-info files based on a build ID
perf symbols: Fix type error when reading a build-id
perf tools: Search for more options when passing args to -h
perf stat: Cache aggregated map entries in extra cpumap
...
This seems to be a mis-reading of how alpha memory ordering works, and
is not backed up by the alpha architecture manual. The helper functions
don't do anything special on any other architectures, and the arguments
that support them being safe on other architectures also argue that they
are safe on alpha.
Basically, the "control dependency" is between a previous read and a
subsequent write that is dependent on the value read. Even if the
subsequent write is actually done speculatively, there is no way that
such a speculative write could be made visible to other cpu's until it
has been committed, which requires validating the speculation.
Note that most weakely ordered architectures (very much including alpha)
do not guarantee any ordering relationship between two loads that depend
on each other on a control dependency:
read A
if (val == 1)
read B
because the conditional may be predicted, and the "read B" may be
speculatively moved up to before reading the value A. So we require the
user to insert a smp_rmb() between the two accesses to be correct:
read A;
if (A == 1)
smp_rmb()
read B
Alpha is further special in that it can break that ordering even if the
*address* of B depends on the read of A, because the cacheline that is
read later may be stale unless you have a memory barrier in between the
pointer read and the read of the value behind a pointer:
read ptr
read offset(ptr)
whereas all other weakly ordered architectures guarantee that the data
dependency (as opposed to just a control dependency) will order the two
accesses. As a result, alpha needs a "smp_read_barrier_depends()" in
between those two reads for them to be ordered.
The coontrol dependency that "READ_ONCE_CTRL()" and "atomic_read_ctrl()"
had was a control dependency to a subsequent *write*, however, and
nobody can finalize such a subsequent write without having actually done
the read. And were you to write such a value to a "stale" cacheline
(the way the unordered reads came to be), that would seem to lose the
write entirely.
So the things that make alpha able to re-order reads even more
aggressively than other weak architectures do not seem to be relevant
for a subsequent write. Alpha memory ordering may be strange, but
there's no real indication that it is *that* strange.
Also, the alpha architecture reference manual very explicitly talks
about the definition of "Dependence Constraints" in section 5.6.1.7,
where a preceding read dominates a subsequent write.
Such a dependence constraint admittedly does not impose a BEFORE (alpha
architecture term for globally visible ordering), but it does guarantee
that there can be no "causal loop". I don't see how you could avoid
such a loop if another cpu could see the stored value and then impact
the value of the first read. Put another way: the read and the write
could not be seen as being out of order wrt other cpus.
So I do not see how these "x_ctrl()" functions can currently be necessary.
I may have to eat my words at some point, but in the absense of clear
proof that alpha actually needs this, or indeed even an explanation of
how alpha could _possibly_ need it, I do not believe these functions are
called for.
And if it turns out that alpha really _does_ need a barrier for this
case, that barrier still should not be "smp_read_barrier_depends()".
We'd have to make up some new speciality barrier just for alpha, along
with the documentation for why it really is necessary.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul E McKenney <paulmck@us.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of WARN_ON in perf_event_output() on unpaded raw samples,
pad them automatically.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
cgroup_exit() is called when a task exits and disassociates the
exiting task from its cgroups and half-attach it to the root cgroup.
This is unnecessary and undesirable.
No controller actually needs an exiting task to be disassociated with
non-root cgroups. Both cpu and perf_event controllers update the
association to the root cgroup from their exit callbacks just to keep
consistent with the cgroup core behavior.
Also, this disassociation makes it difficult to track resources held
by zombies or determine where the zombies came from. Currently, pids
controller is completely broken as it uncharges on exit and zombies
always escape the resource restriction. With cgroup association being
reset on exit, fixing it is pretty painful.
There's no reason to reset cgroup membership on exit. The zombie can
be removed from its css_set so that it doesn't show up on
"cgroup.procs" and thus can't be migrated or interfere with cgroup
removal. It can still pin and point to the css_set so that its cgroup
membership is maintained. This patch makes cgroup core keep zombies
associated with their cgroups at the time of exit.
* Previous patches decoupled populated_cnt tracking from css_set
lifetime, so a dying task can be simply unlinked from its css_set
while pinning and pointing to the css_set. This keeps css_set
association from task side alive while hiding it from "cgroup.procs"
and populated_cnt tracking. The css_set reference is dropped when
the task_struct is freed.
* ->exit() callback no longer needs the css arguments as the
associated css never changes once PF_EXITING is set. Removed.
* cpu and perf_events controllers no longer need ->exit() callbacks.
There's no reason to explicitly switch away on exit. The final
schedule out is enough. The callbacks are removed.
* On traditional hierarchies, nothing changes. "/proc/PID/cgroup"
still reports "/" for all zombies. On the default hierarchy,
"/proc/PID/cgroup" keeps reporting the cgroup that the task belonged
to at the time of exit. If the cgroup gets removed before the task
is reaped, " (deleted)" is appended.
v2: Build brekage due to missing dummy cgroup_free() when
!CONFIG_CGROUP fixed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
There are two races with the current code:
- Another event can join the group and compute a larger header_size
concurrently, if the smaller store wins we'll have an incorrect
header_size set.
- We compute the header_size after the event becomes active,
therefore its possible to use the size before its computed.
Remedy the first by moving the computation inside the ctx::mutex lock,
and the second by placing it _before_ perf_install_in_context().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vince reported that its possible to overflow the various size fields
and get weird stuff if you stick too many events in a group.
Put a lid on this by requiring the fixed record size not exceed 16k.
This is still a fair amount of events (silly amount really) and leaves
plenty room for callchains and stack dwarves while also avoiding
overflowing the u16 variables.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The exclusive_event_installable() stuff only works because its
exclusive with the grouping bits.
Rework the code such that there is a sane place to error out before we
go do things we cannot undo.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Define a new PERF_PMU_TXN_READ interface to read a group of counters
at once.
pmu->start_txn() // Initialize before first event
for each event in group
pmu->read(event); // Queue each event to be read
rc = pmu->commit_txn() // Read/update all queued counters
Note that we use this interface with all PMUs. PMUs that implement this
interface use the ->read() operation to _queue_ the counters to be read
and use ->commit_txn() to actually read all the queued counters at once.
PMUs that don't implement PERF_PMU_TXN_READ ignore ->start_txn() and
->commit_txn() and continue to read counters one at a time.
Thanks to input from Peter Zijlstra.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1441336073-22750-9-git-send-email-sukadev@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When we implement the ability to read several counters at once (using
the PERF_PMU_TXN_READ transaction interface), perf_event_read() can
fail when the 'group' parameter is true (eg: trying to read too many
events at once).
For now, have perf_event_read() return an integer. Ignore the return
value when the 'group' parameter is false.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1441336073-22750-8-git-send-email-sukadev@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In order to enable the use of perf_event_read(.group = true), we need
to invert the sibling-child loop nesting of perf_read_group().
Currently we iterate the child list for each sibling, this precludes
using group reads. Flip things around so we iterate each group for
each child.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[ Made the patch compile and things. ]
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1441336073-22750-7-git-send-email-sukadev@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Enable perf_event_read() to update entire groups at once, this will be
useful for read transactions.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/20150723080435.GE25159@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
perf_event_read() does two things:
- call the PMU to read/update the counter value, and
- compute the total count of the event and its children
Not all callers need both. perf_event_reset() for instance needs the
first piece but doesn't need the second. Similarly, when we implement
the ability to read a group of events using the transaction interface,
we would need the two pieces done independently.
Break up perf_event_read() and have it just read/update the counter
and have the callers compute the total count if necessary.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1441336073-22750-4-git-send-email-sukadev@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, the PMU interface allows reading only one counter at a time.
But some PMUs like the 24x7 counters in Power, support reading several
counters at once. To leveage this functionality, extend the transaction
interface to support a "transaction type".
The first type, PERF_PMU_TXN_ADD, refers to the existing transactions,
i.e. used to _schedule_ all the events on the PMU as a group. A second
transaction type, PERF_PMU_TXN_READ, will be used in a follow-on patch,
by the 24x7 counters to read several counters at once.
Extend the transaction interfaces to the PMU to accept a 'txn_flags'
parameter and use this parameter to ignore any transactions that are
not of type PERF_PMU_TXN_ADD.
Thanks to Peter Zijlstra for his input.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
[peterz: s390 compile fix]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1441336073-22750-3-git-send-email-sukadev@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
cgroup_exit() is not called from copy_process() after commit:
e8604cb436 ("cgroup: fix spurious lockdep warning in cgroup_exit()")
from do_exit(). So this check is useless and the comment is obsolete.
Signed-off-by: Kirill Tkhai <ktkhai@odin.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/55E444C8.3020402@odin.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There are two kexec load syscalls, kexec_load another and kexec_file_load.
kexec_file_load has been splited as kernel/kexec_file.c. In this patch I
split kexec_load syscall code to kernel/kexec.c.
And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.
The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use
kexec_load syscall can bypass the checking.
Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.
Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig. Also updated general kernel code with to
kexec_load syscall.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Petr Tesarik <ptesarik@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull networking updates from David Miller:
"Another merge window, another set of networking changes. I've heard
rumblings that the lightweight tunnels infrastructure has been voted
networking change of the year. But what do I know?
1) Add conntrack support to openvswitch, from Joe Stringer.
2) Initial support for VRF (Virtual Routing and Forwarding), which
allows the segmentation of routing paths without using multiple
devices. There are some semantic kinks to work out still, but
this is a reasonably strong foundation. From David Ahern.
3) Remove spinlock fro act_bpf fast path, from Alexei Starovoitov.
4) Ignore route nexthops with a link down state in ipv6, just like
ipv4. From Andy Gospodarek.
5) Remove spinlock from fast path of act_gact and act_mirred, from
Eric Dumazet.
6) Document the DSA layer, from Florian Fainelli.
7) Add netconsole support to bcmgenet, systemport, and DSA. Also
from Florian Fainelli.
8) Add Mellanox Switch Driver and core infrastructure, from Jiri
Pirko.
9) Add support for "light weight tunnels", which allow for
encapsulation and decapsulation without bearing the overhead of a
full blown netdevice. From Thomas Graf, Jiri Benc, and a cast of
others.
10) Add Identifier Locator Addressing support for ipv6, from Tom
Herbert.
11) Support fragmented SKBs in iwlwifi, from Johannes Berg.
12) Allow perf PMUs to be accessed from eBPF programs, from Kaixu Xia.
13) Add BQL support to 3c59x driver, from Loganaden Velvindron.
14) Stop using a zero TX queue length to mean that a device shouldn't
have a qdisc attached, use an explicit flag instead. From Phil
Sutter.
15) Use generic geneve netdevice infrastructure in openvswitch, from
Pravin B Shelar.
16) Add infrastructure to avoid re-forwarding a packet in software
that was already forwarded by a hardware switch. From Scott
Feldman.
17) Allow AF_PACKET fanout function to be implemented in a bpf
program, from Willem de Bruijn"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1458 commits)
netfilter: nf_conntrack: make nf_ct_zone_dflt built-in
netfilter: nf_dup{4, 6}: fix build error when nf_conntrack disabled
net: fec: clear receive interrupts before processing a packet
ipv6: fix exthdrs offload registration in out_rt path
xen-netback: add support for multicast control
bgmac: Update fixed_phy_register()
sock, diag: fix panic in sock_diag_put_filterinfo
flow_dissector: Use 'const' where possible.
flow_dissector: Fix function argument ordering dependency
ixgbe: Resolve "initialized field overwritten" warnings
ixgbe: Remove bimodal SR-IOV disabling
ixgbe: Add support for reporting 2.5G link speed
ixgbe: fix bounds checking in ixgbe_setup_tc for 82598
ixgbe: support for ethtool set_rxfh
ixgbe: Avoid needless PHY access on copper phys
ixgbe: cleanup to use cached mask value
ixgbe: Remove second instance of lan_id variable
ixgbe: use kzalloc for allocating one thing
flow: Move __get_hash_from_flowi{4,6} into flow_dissector.c
ixgbe: Remove unused PCI bus types
...
A question [1] was raised about the use of page::private in AUX buffer
allocations, so let's add a clarification about its intended use.
The private field and flag are used by perf's rb_alloc_aux() path to
tell the pmu driver the size of each high-order allocation, so that the
driver can program those appropriately into its hardware. This only
matters for PMUs that don't support hardware scatter tables. Otherwise,
every page in the buffer is just a page.
This patch adds a comment about the private field to the AUX buffer
allocation path.
[1] http://marc.info/?l=linux-kernel&m=143803696607968
Reported-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438063204-665-1-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
I ran the perf fuzzer, which triggered some WARN()s which are due to
trying to stop/restart an event on the wrong CPU.
Use the normal IPI pattern to ensure we run the code on the correct CPU.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: bad7192b84 ("perf: Fix PERF_EVENT_IOC_PERIOD to force-reset the period")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If rb->aux_refcount is decremented to zero before rb->refcount,
__rb_free_aux() may be called twice resulting in a double free of
rb->aux_pages. Fix this by adding a check to __rb_free_aux().
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 57ffc5ca67 ("perf: Fix AUX buffer refcounting")
Link: http://lkml.kernel.org/r/1437953468.12842.17.camel@decadent.org.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch add three core perf APIs:
- perf_event_attrs(): export the struct perf_event_attr from struct
perf_event;
- perf_event_get(): get the struct perf_event from the given fd;
- perf_event_read_local(): read the events counters active on the
current CPU;
These APIs are needed when accessing events counters in eBPF programs.
The API perf_event_read_local() comes from Peter and I add the
corresponding SOB.
Signed-off-by: Kaixu Xia <xiakaixu@huawei.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
By copying BPF related operation to uprobe processing path, this patch
allow users attach BPF programs to uprobes like what they are already
doing on kprobes.
After this patch, users are allowed to use PERF_EVENT_IOC_SET_BPF on a
uprobe perf event. Which make it possible to profile user space programs
and kernel events together using BPF.
Because of this patch, CONFIG_BPF_EVENTS should be selected by
CONFIG_UPROBE_EVENT to ensure trace_call_bpf() is compiled even if
KPROBE_EVENT is not set.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently, the PT driver zeroes out the status register every time before
starting the event. However, all the writable bits are already taken care
of in pt_handle_status() function, except the new PacketByteCnt field,
which in new versions of PT contains the number of packet bytes written
since the last sync (PSB) packet. Zeroing it out before enabling PT forces
a sync packet to be written. This means that, with the existing code, a
sync packet (PSB and PSBEND, 18 bytes in total) will be generated every
time a PT event is scheduled in.
To avoid these unnecessary syncs and save a WRMSR in the fast path, this
patch changes the default behavior to not clear PacketByteCnt field, so
that the sync packets will be generated with the period specified as
"psb_period" attribute config field. This has little impact on the trace
data as the other packets that are normally sent within PSB+ (between PSB
and PSBEND) have their own generation scenarios which do not depend on the
sync packets.
One exception where we do need to force PSB like this when tracing starts,
so that the decoder has a clear sync point in the trace. For this purpose
we aready have hw::itrace_started flag, which we are currently using to
output PERF_RECORD_ITRACE_START. This patch moves setting itrace_started
from perf core to the pmu::start, where it should still be 0 on the very
first run.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1438264104-16189-1-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vince reported that the fasync signal stuff doesn't work proper for
inherited events. So fix that.
Installing fasync allocates memory and sets filp->f_flags |= FASYNC,
which upon the demise of the file descriptor ensures the allocation is
freed and state is updated.
Now for perf, we can have the events stick around for a while after the
original FD is dead because of references from child events. So we
cannot copy the fasync pointer around. We can however consistently use
the parent's fasync, as that will be updated.
Reported-and-Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Cc: Arnaldo Carvalho deMelo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1434011521.1495.71.camel@twins
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The xol_free_insn_slot()->waitqueue_active() check is buggy. We
need mb() after we set the conditon for wait_event(), or
xol_take_insn_slot() can miss the wakeup.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134036.GA4799@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Change xol_add_vma() to use _install_special_mapping(), this way
we can name the vma installed by uprobes. Currently it looks
like private anonymous mapping, this is confusing and
complicates the debugging. With this change /proc/$pid/maps
reports "[uprobes]".
As a side effect this will cause core dumps to include the XOL vma
and I think this is good; this can help to debug the problem if
the app crashed because it was probed.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134033.GA4796@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
install_special_mapping(pages) expects that "pages" is the zero-
terminated array while xol_add_vma() passes &area->page, this
means that special_mapping_fault() can wrongly use the next
member in xol_area (vaddr) as "struct page *".
Fortunately, this area is not expandable so pgoff != 0 isn't
possible (modulo bugs in special_mapping_vmops), but still this
does not look good.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134031.GA4789@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The previous change documents that cleanup_return_instances()
can't always detect the dead frames, the stack can grow. But
there is one special case which imho worth fixing:
arch_uretprobe_is_alive() can return true when the stack didn't
actually grow, but the next "call" insn uses the already
invalidated frame.
Test-case:
#include <stdio.h>
#include <setjmp.h>
jmp_buf jmp;
int nr = 1024;
void func_2(void)
{
if (--nr == 0)
return;
longjmp(jmp, 1);
}
void func_1(void)
{
setjmp(jmp);
func_2();
}
int main(void)
{
func_1();
return 0;
}
If you ret-probe func_1() and func_2() prepare_uretprobe() hits
the MAX_URETPROBE_DEPTH limit and "return" from func_2() is not
reported.
When we know that the new call is not chained, we can do the
more strict check. In this case "sp" points to the new ret-addr,
so every frame which uses the same "sp" must be dead. The only
complication is that arch_uretprobe_is_alive() needs to know was
it chained or not, so we add the new RP_CHECK_CHAIN_CALL enum
and change prepare_uretprobe() to pass RP_CHECK_CALL only if
!chained.
Note: arch_uretprobe_is_alive() could also re-read *sp and check
if this word is still trampoline_vaddr. This could obviously
improve the logic, but I would like to avoid another
copy_from_user() especially in the case when we can't avoid the
false "alive == T" positives.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134028.GA4786@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86 doesn't care (so far), but as Pratyush Anand pointed
out other architectures might want why arch_uretprobe_is_alive()
was called and use different checks depending on the context.
Add the new argument to distinguish 2 callers.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134026.GA4779@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Change prepare_uretprobe() to flush the !arch_uretprobe_is_alive()
return_instance's. This is not needed correctness-wise, but can help
to avoid the failure caused by MAX_URETPROBE_DEPTH.
Note: in this case arch_uretprobe_is_alive() can be false
positive, the stack can grow after longjmp(). Unfortunately, the
kernel can't 100% solve this problem, but see the next patch.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134023.GA4776@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Test-case:
#include <stdio.h>
#include <setjmp.h>
jmp_buf jmp;
void func_2(void)
{
longjmp(jmp, 1);
}
void func_1(void)
{
if (setjmp(jmp))
return;
func_2();
printf("ERR!! I am running on the caller's stack\n");
}
int main(void)
{
func_1();
return 0;
}
fails if you probe func_1() and func_2() because
handle_trampoline() assumes that the probed function should must
return and hit the bp installed be prepare_uretprobe(). But in
this case func_2() does not return, so when func_1() returns the
kernel uses the no longer valid return_instance of func_2().
Change handle_trampoline() to unwind ->return_instances until we
know that the next chain is alive or NULL, this ensures that the
current chain is the last we need to report and free.
Alternatively, every return_instance could use unique
trampoline_vaddr, in this case we could use it as a key. And
this could solve the problem with sigaltstack() automatically.
But this approach needs more changes, and it puts the "hard"
limit on MAX_URETPROBE_DEPTH. Plus it can not solve another
problem partially fixed by the next patch.
Note: this change has no effect on !x86, the arch-agnostic
version of arch_uretprobe_is_alive() just returns "true".
TODO: as documented by the previous change, arch_uretprobe_is_alive()
can be fooled by sigaltstack/etc.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134021.GA4773@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add the x86 specific version of arch_uretprobe_is_alive()
helper. It returns true if the stack frame mangled by
prepare_uretprobe() is still on stack. So if it returns false,
we know that the probed function has already returned.
We add the new return_instance->stack member and change the
generic code to initialize it in prepare_uretprobe, but it
should be equally useful for other architectures.
TODO: this assumes that the probed application can't use
multiple stacks (say sigaltstack). We will try to improve
this logic later.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134018.GA4766@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add the new "weak" helper, arch_uretprobe_is_alive(), used by
the next patches. It should return true if this return_instance
is still valid. The arch agnostic version just always returns
true.
The patch exports "struct return_instance" for the architectures
which want to override this hook. We can also cleanup
prepare_uretprobe() if we pass the new return_instance to
arch_uretprobe_hijack_return_addr().
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134016.GA4762@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
No functional changes, preparation.
Add the new helper, find_next_ret_chain(), which finds the first
!chained entry and returns its ->next. Yes, it is suboptimal. We
probably want to turn ->chained into ->start_of_this_chain
pointer and avoid another loop. But this needs the boring
changes in dup_utask(), so lets do this later.
Change the main loop in handle_trampoline() to unwind the stack
until ri is equal to the pointer returned by this new helper.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134013.GA4755@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Turn the last pr_warn() in uprobes.c into uprobe_warn().
While at it:
- s/kzalloc/kmalloc, we initialize every member of 'ri'
- remove the pointless comment above the obvious code
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134010.GA4752@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1. It doesn't make sense to continue if handle_trampoline()
fails, change handle_swbp() to always return after this call.
2. Turn pr_warn() into uprobe_warn(), and change
handle_trampoline() to send SIGILL on failure. It is pointless to
return to user mode with the corrupted instruction_pointer() which
we can't restore.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134008.GA4745@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We can simplify uprobe_free_utask() and handle_uretprobe_chain()
if we add a simple helper which does put_uprobe/kfree and
returns the ->next return_instance.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134006.GA4740@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cosmetic. Add the new trivial helper, get_uprobe(). It matches
put_uprobe() we already have and we can simplify a couple of its
users.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134003.GA4736@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A recent fix to the shadow timestamp inadvertly broke the running time
accounting.
We must not update the running timestamp if we fail to schedule the
event, the event will not have ran. This can (and did) result in
negative total runtime because the stopped timestamp was before the
running timestamp (we 'started' but never stopped the event -- because
it never really started we didn't have to stop it either).
Reported-and-Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 72f669c008 ("perf: Update shadow timestamp before add event")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # 4.1
Cc: Shaohua Li <shli@fb.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
There are already two events for context switches, namely the tracepoint
sched:sched_switch and the software event context_switches.
Unfortunately neither are suitable for use by non-privileged users for
the purpose of synchronizing hardware trace data (e.g. Intel PT) to the
context switch.
Tracepoints are no good at all for non-privileged users because they
need either CAP_SYS_ADMIN or /proc/sys/kernel/perf_event_paranoid <= -1.
On the other hand, kernel software events need either CAP_SYS_ADMIN or
/proc/sys/kernel/perf_event_paranoid <= 1.
Now many distributions do default perf_event_paranoid to 1 making
context_switches a contender, except it has another problem (which is
also shared with sched:sched_switch) which is that it happens before
perf schedules events out instead of after perf schedules events in.
Whereas a privileged user can see all the events anyway, a
non-privileged user only sees events for their own processes, in other
words they see when their process was scheduled out not when it was
scheduled in. That presents two problems to use the event:
1. the information comes too late, so tools have to look ahead in the
event stream to find out what the current state is
2. if they are unlucky tracing might have stopped before the
context-switches event is recorded.
This new PERF_RECORD_SWITCH event does not have those problems
and it also has a couple of other small advantages.
It is easier to use because it is an auxiliary event (like mmap, comm
and task events) which can be enabled by setting a single bit. It is
smaller than sched:sched_switch and easier to parse.
To make the event useful for privileged users also, if the
context is cpu-wide then the event record will be
PERF_RECORD_SWITCH_CPU_WIDE which is the same as
PERF_RECORD_SWITCH except it also provides the next or
previous pid/tid.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Jiri Olsa <jolsa@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1437471846-26995-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Its currently possible to drop the last refcount to the aux buffer
from NMI context, which results in the expected fireworks.
The refcounting needs a bigger overhaul, but to cure the immediate
problem, delay the freeing by using an irq_work.
Reviewed-and-tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150618103249.GK19282@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull more vfs updates from Al Viro:
"Assorted VFS fixes and related cleanups (IMO the most interesting in
that part are f_path-related things and Eric's descriptor-related
stuff). UFS regression fixes (it got broken last cycle). 9P fixes.
fs-cache series, DAX patches, Jan's file_remove_suid() work"
[ I'd say this is much more than "fixes and related cleanups". The
file_table locking rule change by Eric Dumazet is a rather big and
fundamental update even if the patch isn't huge. - Linus ]
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
9p: cope with bogus responses from server in p9_client_{read,write}
p9_client_write(): avoid double p9_free_req()
9p: forgetting to cancel request on interrupted zero-copy RPC
dax: bdev_direct_access() may sleep
block: Add support for DAX reads/writes to block devices
dax: Use copy_from_iter_nocache
dax: Add block size note to documentation
fs/file.c: __fget() and dup2() atomicity rules
fs/file.c: don't acquire files->file_lock in fd_install()
fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
vfs: avoid creation of inode number 0 in get_next_ino
namei: make set_root_rcu() return void
make simple_positive() public
ufs: use dir_pages instead of ufs_dir_pages()
pagemap.h: move dir_pages() over there
remove the pointless include of lglock.h
fs: cleanup slight list_entry abuse
xfs: Correctly lock inode when removing suid and file capabilities
fs: Call security_ops->inode_killpriv on truncate
fs: Provide function telling whether file_remove_privs() will do anything
...
"monitonic raw". Also some enhancements to make the ring buffer even
faster. But the biggest and most noticeable change is the renaming of
the ftrace* files, structures and variables that have to deal with
trace events.
Over the years I've had several developers tell me about their confusion
with what ftrace is compared to events. Technically, "ftrace" is the
infrastructure to do the function hooks, which include tracing and also
helps with live kernel patching. But the trace events are a separate
entity altogether, and the files that affect the trace events should
not be named "ftrace". These include:
include/trace/ftrace.h -> include/trace/trace_events.h
include/linux/ftrace_event.h -> include/linux/trace_events.h
Also, functions that are specific for trace events have also been renamed:
ftrace_print_*() -> trace_print_*()
(un)register_ftrace_event() -> (un)register_trace_event()
ftrace_event_name() -> trace_event_name()
ftrace_trigger_soft_disabled()-> trace_trigger_soft_disabled()
ftrace_define_fields_##call() -> trace_define_fields_##call()
ftrace_get_offsets_##call() -> trace_get_offsets_##call()
Structures have been renamed:
ftrace_event_file -> trace_event_file
ftrace_event_{call,class} -> trace_event_{call,class}
ftrace_event_buffer -> trace_event_buffer
ftrace_subsystem_dir -> trace_subsystem_dir
ftrace_event_raw_##call -> trace_event_raw_##call
ftrace_event_data_offset_##call-> trace_event_data_offset_##call
ftrace_event_type_funcs_##call -> trace_event_type_funcs_##call
And a few various variables and flags have also been updated.
This has been sitting in linux-next for some time, and I have not heard
a single complaint about this rename breaking anything. Mostly because
these functions, variables and structures are mostly internal to the
tracing system and are seldom (if ever) used by anything external to that.
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Merge tag 'trace-v4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"This patch series contains several clean ups and even a new trace
clock "monitonic raw". Also some enhancements to make the ring buffer
even faster. But the biggest and most noticeable change is the
renaming of the ftrace* files, structures and variables that have to
deal with trace events.
Over the years I've had several developers tell me about their
confusion with what ftrace is compared to events. Technically,
"ftrace" is the infrastructure to do the function hooks, which include
tracing and also helps with live kernel patching. But the trace
events are a separate entity altogether, and the files that affect the
trace events should not be named "ftrace". These include:
include/trace/ftrace.h -> include/trace/trace_events.h
include/linux/ftrace_event.h -> include/linux/trace_events.h
Also, functions that are specific for trace events have also been renamed:
ftrace_print_*() -> trace_print_*()
(un)register_ftrace_event() -> (un)register_trace_event()
ftrace_event_name() -> trace_event_name()
ftrace_trigger_soft_disabled() -> trace_trigger_soft_disabled()
ftrace_define_fields_##call() -> trace_define_fields_##call()
ftrace_get_offsets_##call() -> trace_get_offsets_##call()
Structures have been renamed:
ftrace_event_file -> trace_event_file
ftrace_event_{call,class} -> trace_event_{call,class}
ftrace_event_buffer -> trace_event_buffer
ftrace_subsystem_dir -> trace_subsystem_dir
ftrace_event_raw_##call -> trace_event_raw_##call
ftrace_event_data_offset_##call-> trace_event_data_offset_##call
ftrace_event_type_funcs_##call -> trace_event_type_funcs_##call
And a few various variables and flags have also been updated.
This has been sitting in linux-next for some time, and I have not
heard a single complaint about this rename breaking anything. Mostly
because these functions, variables and structures are mostly internal
to the tracing system and are seldom (if ever) used by anything
external to that"
* tag 'trace-v4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
ring_buffer: Allow to exit the ring buffer benchmark immediately
ring-buffer-benchmark: Fix the wrong type
ring-buffer-benchmark: Fix the wrong param in module_param
ring-buffer: Add enum names for the context levels
ring-buffer: Remove useless unused tracing_off_permanent()
ring-buffer: Give NMIs a chance to lock the reader_lock
ring-buffer: Add trace_recursive checks to ring_buffer_write()
ring-buffer: Allways do the trace_recursive checks
ring-buffer: Move recursive check to per_cpu descriptor
ring-buffer: Add unlikelys to make fast path the default
tracing: Rename ftrace_get_offsets_##call() to trace_event_get_offsets_##call()
tracing: Rename ftrace_define_fields_##call() to trace_event_define_fields_##call()
tracing: Rename ftrace_event_type_funcs_##call to trace_event_type_funcs_##call
tracing: Rename ftrace_data_offset_##call to trace_event_data_offset_##call
tracing: Rename ftrace_raw_##call event structures to trace_event_raw_##call
tracing: Rename ftrace_trigger_soft_disabled() to trace_trigger_soft_disabled()
tracing: Rename FTRACE_EVENT_FL_* flags to EVENT_FILE_FL_*
tracing: Rename struct ftrace_subsystem_dir to trace_subsystem_dir
tracing: Rename ftrace_event_name() to trace_event_name()
tracing: Rename FTRACE_MAX_EVENT to TRACE_EVENT_TYPE_MAX
...
Pull ARM updates from Russell King:
"Bigger items included in this update are:
- A series of updates from Arnd for ARM randconfig build failures
- Updates from Dmitry for StrongARM SA-1100 to move IRQ handling to
drivers/irqchip/
- Move ARMs SP804 timer to drivers/clocksource/
- Perf updates from Mark Rutland in preparation to move the ARM perf
code into drivers/ so it can be shared with ARM64.
- MCPM updates from Nicolas
- Add support for taking platform serial number from DT
- Re-implement Keystone2 physical address space switch to conform to
architecture requirements
- Clean up ARMv7 LPAE code, which goes in hand with the Keystone2
changes.
- L2C cleanups to avoid unlocking caches if we're prevented by the
secure support to unlock.
- Avoid cleaning a potentially dirty cache containing stale data on
CPU initialisation
- Add ARM-only entry point for secondary startup (for machines that
can only call into a Thumb kernel in ARM mode). Same thing is also
done for the resume entry point.
- Provide arch_irqs_disabled via asm-generic
- Enlarge ARMv7M vector table
- Always use BFD linker for VDSO, as gold doesn't accept some of the
options we need.
- Fix an incorrect BSYM (for Thumb symbols) usage, and convert all
BSYM compiler macros to a "badr" (for branch address).
- Shut up compiler warnings provoked by our cmpxchg() implementation.
- Ensure bad xchg sizes fail to link"
* 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (75 commits)
ARM: Fix build if CLKDEV_LOOKUP is not configured
ARM: fix new BSYM() usage introduced via for-arm-soc branch
ARM: 8383/1: nommu: avoid deprecated source register on mov
ARM: 8391/1: l2c: add options to overwrite prefetching behavior
ARM: 8390/1: irqflags: Get arch_irqs_disabled from asm-generic
ARM: 8387/1: arm/mm/dma-mapping.c: Add arm_coherent_dma_mmap
ARM: 8388/1: tcm: Don't crash when TCM banks are protected by TrustZone
ARM: 8384/1: VDSO: force use of BFD linker
ARM: 8385/1: VDSO: group link options
ARM: cmpxchg: avoid warnings from macro-ized cmpxchg() implementations
ARM: remove __bad_xchg definition
ARM: 8369/1: ARMv7M: define size of vector table for Vybrid
ARM: 8382/1: clocksource: make ARM_TIMER_SP804 depend on GENERIC_SCHED_CLOCK
ARM: 8366/1: move Dual-Timer SP804 driver to drivers/clocksource
ARM: 8365/1: introduce sp804_timer_disable and remove arm_timer.h inclusion
ARM: 8364/1: fix BE32 module loading
ARM: 8360/1: add secondary_startup_arm prototype in header file
ARM: 8359/1: correct secondary_startup_arm mode
ARM: proc-v7: sanitise and document registers around errata
ARM: proc-v7: clean up MIDR access
...
Pull timer updates from Thomas Gleixner:
"A rather largish update for everything time and timer related:
- Cache footprint optimizations for both hrtimers and timer wheel
- Lower the NOHZ impact on systems which have NOHZ or timer migration
disabled at runtime.
- Optimize run time overhead of hrtimer interrupt by making the clock
offset updates smarter
- hrtimer cleanups and removal of restrictions to tackle some
problems in sched/perf
- Some more leap second tweaks
- Another round of changes addressing the 2038 problem
- First step to change the internals of clock event devices by
introducing the necessary infrastructure
- Allow constant folding for usecs/msecs_to_jiffies()
- The usual pile of clockevent/clocksource driver updates
The hrtimer changes contain updates to sched, perf and x86 as they
depend on them plus changes all over the tree to cleanup API changes
and redundant code, which got copied all over the place. The y2038
changes touch s390 to remove the last non 2038 safe code related to
boot/persistant clock"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (114 commits)
clocksource: Increase dependencies of timer-stm32 to limit build wreckage
timer: Minimize nohz off overhead
timer: Reduce timer migration overhead if disabled
timer: Stats: Simplify the flags handling
timer: Replace timer base by a cpu index
timer: Use hlist for the timer wheel hash buckets
timer: Remove FIFO "guarantee"
timers: Sanitize catchup_timer_jiffies() usage
hrtimer: Allow hrtimer::function() to free the timer
seqcount: Introduce raw_write_seqcount_barrier()
seqcount: Rename write_seqcount_barrier()
hrtimer: Fix hrtimer_is_queued() hole
hrtimer: Remove HRTIMER_STATE_MIGRATE
selftest: Timers: Avoid signal deadlock in leap-a-day
timekeeping: Copy the shadow-timekeeper over the real timekeeper last
clockevents: Check state instead of mode in suspend/resume path
selftests: timers: Add leap-second timer edge testing to leap-a-day.c
ntp: Do leapsecond adjustment in adjtimex read path
time: Prevent early expiry of hrtimers[CLOCK_REALTIME] at the leap second edge
ntp: Introduce and use SECS_PER_DAY macro instead of 86400
...
Pull perf fixes from Ingo Molnar:
"These are the left over fixes from the v4.1 cycle"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools: Fix build breakage if prefix= is specified
perf/x86: Honor the architectural performance monitoring version
perf/x86/intel: Fix PMI handling for Intel PT
perf/x86/intel/bts: Fix DS area sharing with x86_pmu events
perf/x86: Add more Broadwell model numbers
perf: Fix ring_buffer_attach() RCU sync, again
Pull perf updates from Ingo Molnar:
"Kernel side changes mostly consist of work on x86 PMU drivers:
- x86 Intel PT (hardware CPU tracer) improvements (Alexander
Shishkin)
- x86 Intel CQM (cache quality monitoring) improvements (Thomas
Gleixner)
- x86 Intel PEBSv3 support (Peter Zijlstra)
- x86 Intel PEBS interrupt batching support for lower overhead
sampling (Zheng Yan, Kan Liang)
- x86 PMU scheduler fixes and improvements (Peter Zijlstra)
There's too many tooling improvements to list them all - here are a
few select highlights:
'perf bench':
- Introduce new 'perf bench futex' benchmark: 'wake-parallel', to
measure parallel waker threads generating contention for kernel
locks (hb->lock). (Davidlohr Bueso)
'perf top', 'perf report':
- Allow disabling/enabling events dynamicaly in 'perf top':
a 'perf top' session can instantly become a 'perf report'
one, i.e. going from dynamic analysis to a static one,
returning to a dynamic one is possible, to toogle the
modes, just press 'f' to 'freeze/unfreeze' the sampling. (Arnaldo Carvalho de Melo)
- Make Ctrl-C stop processing on TUI, allowing interrupting the load of big
perf.data files (Namhyung Kim)
'perf probe': (Masami Hiramatsu)
- Support glob wildcards for function name
- Support $params special probe argument: Collect all function arguments
- Make --line checks validate C-style function name.
- Add --no-inlines option to avoid searching inline functions
- Greatly speed up 'perf probe --list' by caching debuginfo.
- Improve --filter support for 'perf probe', allowing using its arguments
on other commands, as --add, --del, etc.
'perf sched':
- Add option in 'perf sched' to merge like comms to lat output (Josef Bacik)
Plus tons of infrastructure work - in particular preparation for
upcoming threaded perf report support, but also lots of other work -
and fixes and other improvements. See (much) more details in the
shortlog and in the git log"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (305 commits)
perf tools: Configurable per thread proc map processing time out
perf tools: Add time out to force stop proc map processing
perf report: Fix sort__sym_cmp to also compare end of symbol
perf hists browser: React to unassigned hotkey pressing
perf top: Tell the user how to unfreeze events after pressing 'f'
perf hists browser: Honour the help line provided by builtin-{top,report}.c
perf hists browser: Do not exit when 'f' is pressed in 'report' mode
perf top: Replace CTRL+z with 'f' as hotkey for enable/disable events
perf annotate: Rename source_line_percent to source_line_samples
perf annotate: Display total number of samples with --show-total-period
perf tools: Ensure thread-stack is flushed
perf top: Allow disabling/enabling events dynamicly
perf evlist: Add toggle_enable() method
perf trace: Fix race condition at the end of started workloads
perf probe: Speed up perf probe --list by caching debuginfo
perf probe: Show usage even if the last event is skipped
perf tools: Move libtraceevent dynamic list to separated LDFLAGS variable
perf tools: Fix a problem when opening old perf.data with different byte order
perf tools: Ignore .config-detected in .gitignore
perf probe: Fix to return error if no probe is added
...
Pull RCU updates from Ingo Molnar:
- Continued initialization/Kconfig updates: hide most Kconfig options
from unsuspecting users.
There's now a single high level configuration option:
*
* RCU Subsystem
*
Make expert-level adjustments to RCU configuration (RCU_EXPERT) [N/y/?] (NEW)
Which if answered in the negative, leaves us with a single
interactive configuration option:
Offload RCU callback processing from boot-selected CPUs (RCU_NOCB_CPU) [N/y/?] (NEW)
All the rest of the RCU options are configured automatically. Later
on we'll remove this single leftover configuration option as well.
- Remove all uses of RCU-protected array indexes: replace the
rcu_[access|dereference]_index_check() APIs with READ_ONCE() and
rcu_lockdep_assert()
- RCU CPU-hotplug cleanups
- Updates to Tiny RCU: a race fix and further code shrinkage.
- RCU torture-testing updates: fixes, speedups, cleanups and
documentation updates.
- Miscellaneous fixes
- Documentation updates
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
rcutorture: Allow repetition factors in Kconfig-fragment lists
rcutorture: Display "make oldconfig" errors
rcutorture: Update TREE_RCU-kconfig.txt
rcutorture: Make rcutorture scripts force RCU_EXPERT
rcutorture: Update configuration fragments for rcutree.rcu_fanout_exact
rcutorture: TASKS_RCU set directly, so don't explicitly set it
rcutorture: Test SRCU cleanup code path
rcutorture: Replace barriers with smp_store_release() and smp_load_acquire()
locktorture: Change longdelay_us to longdelay_ms
rcutorture: Allow negative values of nreaders to oversubscribe
rcutorture: Exchange TREE03 and TREE08 NR_CPUS, speed up CPU hotplug
rcutorture: Exchange TREE03 and TREE04 geometries
locktorture: fix deadlock in 'rw_lock_irq' type
rcu: Correctly handle non-empty Tiny RCU callback list with none ready
rcutorture: Test both RCU-sched and RCU-bh for Tiny RCU
rcu: Further shrink Tiny RCU by making empty functions static inlines
rcu: Conditionally compile RCU's eqs warnings
rcu: Remove prompt for RCU implementation
rcu: Make RCU able to tolerate undefined CONFIG_RCU_KTHREAD_PRIO
rcu: Make RCU able to tolerate undefined CONFIG_RCU_FANOUT_LEAF
...
While looking for other users of get_state/cond_sync. I Found
ring_buffer_attach() and it looks obviously buggy?
Don't we need to ensure that we have "synchronize" _between_
list_del() and list_add() ?
IOW. Suppose that ring_buffer_attach() preempts right_after
get_state_synchronize_rcu() and gp completes before spin_lock().
In this case cond_synchronize_rcu() does nothing and we reuse
->rb_entry without waiting for gp in between?
It also moves the ->rcu_pending check under "if (rb)", to make it
more readable imo.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Cc: der.herr@hofr.at
Cc: josh@joshtriplett.org
Cc: tj@kernel.org
Fixes: b69cf53640 ("perf: Fix a race between ring_buffer_detach() and ring_buffer_attach()")
Link: http://lkml.kernel.org/r/20150530200425.GA15748@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
After enlarging the PEBS interrupt threshold, there may be some mixed up
PEBS samples which are discarded by the kernel.
This patch makes the kernel emit a PERF_RECORD_LOST_SAMPLES record with
the number of possible discarded records when it is impossible to demux
the samples.
It makes sure the user is not left in the dark about such discards.
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1431285195-14269-8-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When the PEBS interrupt threshold is larger than one record and the
machine supports multiple PEBS events, the records of these events are
mixed up and we need to demultiplex them.
Demuxing the records is hard because the hardware is deficient. The
hardware has two issues that, when combined, create impossible
scenarios to demux.
The first issue is that the 'status' field of the PEBS record is a copy
of the GLOBAL_STATUS MSR at PEBS assist time. To see why this is a
problem let us first describe the regular PEBS cycle:
A) the CTRn value reaches 0:
- the corresponding bit in GLOBAL_STATUS gets set
- we start arming the hardware assist
< some unspecified amount of time later -- this could cover multiple
events of interest >
B) the hardware assist is armed, any next event will trigger it
C) a matching event happens:
- the hardware assist triggers and generates a PEBS record
this includes a copy of GLOBAL_STATUS at this moment
- if we auto-reload we (re)set CTRn
- we clear the relevant bit in GLOBAL_STATUS
Now consider the following chain of events:
A0, B0, A1, C0
The event generated for counter 0 will include a status with counter 1
set, even though its not at all related to the record. A similar thing
can happen with a !PEBS event if it just happens to overflow at the
right moment.
The second issue is that the hardware will only emit one record for two
or more counters if the event that triggers the assist is 'close'. The
'close' can be several cycles. In some cases even the complete assist,
if the event is something that doesn't need retirement.
For instance, consider this chain of events:
A0, B0, A1, B1, C01
Where C01 is an event that triggers both hardware assists, we will
generate but a single record, but again with both counters listed in the
status field.
This time the record pertains to both events.
Note that these two cases are different but undistinguishable with the
data as generated. Therefore demuxing records with multiple PEBS bits
(we can safely ignore status bits for !PEBS counters) is impossible.
Furthermore we cannot emit the record to both events because that might
cause a data leak -- the events might not have the same privileges -- so
what this patch does is discard such events.
The assumption/hope is that such discards will be rare.
Here lists some possible ways you may get high discard rate.
- when you count the same thing multiple times. But it is not a useful
configuration.
- you can be unfortunate if you measure with a userspace only PEBS
event along with either a kernel or unrestricted PEBS event. Imagine
the event triggering and setting the overflow flag right before
entering the kernel. Then all kernel side events will end up with
multiple bits set.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
[ Changelog improvements. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1430940834-8964-4-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull RCU changes from Paul E. McKenney:
- Initialization/Kconfig updates: hide most Kconfig options from unsuspecting users.
There's now a single high level configuration option:
*
* RCU Subsystem
*
Make expert-level adjustments to RCU configuration (RCU_EXPERT) [N/y/?] (NEW)
Which if answered in the negative, leaves us with a single interactive
configuration option:
Offload RCU callback processing from boot-selected CPUs (RCU_NOCB_CPU) [N/y/?] (NEW)
All the rest of the RCU options are configured automatically.
- Remove all uses of RCU-protected array indexes: replace the
rcu_[access|dereference]_index_check() APIs with READ_ONCE() and rcu_lockdep_assert().
- RCU CPU-hotplug cleanups.
- Updates to Tiny RCU: a race fix and further code shrinkage.
- RCU torture-testing updates: fixes, speedups, cleanups and
documentation updates.
- Miscellaneous fixes.
- Documentation updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The current formulation of control dependencies fails on DEC Alpha,
which does not respect dependencies of any kind unless an explicit
memory barrier is provided. This means that the current fomulation of
control dependencies fails on Alpha. This commit therefore creates a
READ_ONCE_CTRL() that has the same overhead on non-Alpha systems, but
causes Alpha to produce the needed ordering. This commit also applies
READ_ONCE_CTRL() to the one known use of control dependencies.
Use of READ_ONCE_CTRL() also has the beneficial effect of adding a bit
of self-documentation to control dependencies.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
In certain circumstances it may not be possible to schedule particular
events due to constraints other than a lack of hardware counters (e.g.
on big.LITTLE systems where CPUs support different events). The core
perf event code does not distinguish these cases and pessimistically
assumes that any failure to schedule an event means that it is not worth
attempting to schedule later events, even if some hardware counters are
still unused.
When an event a pmu cannot schedule exists in a flexible group list it
can unnecessarily prevent event groups following it in the list from
being scheduled (until it is rotated to the end of the list). This means
some events are scheduled for only a portion of the time they could be,
and for short running programs no events may be scheduled if the list is
initially sorted in an unfortunate order.
This patch adds a new (optional) filter_match function pointer to struct
pmu which a pmu driver can use to tell perf core when an event matches
pmu-specific scheduling requirements. This plugs into the existing
event_filter_match logic, and makes it possible to avoid the scheduling
problem described above. When no filter is provided by the PMU, the
existing behaviour is retained.
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
PMUs that don't support hardware scatter tables require big contiguous
chunks of memory and a PMI to switch between them. However, in overwrite
using a PMI for this purpose adds extra overhead that the users would
like to avoid. Thus, in overwrite mode for such PMUs we can only allow
one contiguous chunk for the entire requested buffer.
This patch changes the behavior accordingly, so that if the buddy allocator
fails to come up with a single high-order chunk for the entire requested
buffer, the allocation will fail.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1432308626-18845-2-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
there is a race between perf_event_free_bpf_prog() and free_trace_kprobe():
__free_event()
event->destroy(event)
tp_perf_event_destroy()
perf_trace_destroy()
perf_trace_event_unreg()
which is dropping event->tp_event->perf_refcount and allows to proceed in:
unregister_trace_kprobe()
unregister_kprobe_event()
trace_remove_event_call()
probe_remove_event_call()
free_trace_kprobe()
while __free_event does:
call_rcu(&event->rcu_head, free_event_rcu);
free_event_rcu()
perf_event_free_bpf_prog()
To fix the race simply move perf_event_free_bpf_prog() before
event->destroy(), since event->tp_event is still valid at that point.
Note, perf_trace_destroy() is not racing with trace_remove_event_call()
since they both grab event_mutex.
Reported-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: lizefan@huawei.com
Cc: pi3orama@163.com
Fixes: 2541517c32 ("tracing, perf: Implement BPF programs attached to kprobes")
Link: http://lkml.kernel.org/r/1431717321-28772-1-git-send-email-ast@plumgrid.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In the below two commits (see Fixes) we have periodic timers that can
stop themselves when they're no longer required, but need to be
(re)-started when their idle condition changes.
Further complications is that we want the timer handler to always do
the forward such that it will always correctly deal with the overruns,
and we do not want to race such that the handler has already decided
to stop, but the (external) restart sees the timer still active and we
end up with a 'lost' timer.
The problem with the current code is that the re-start can come before
the callback does the forward, at which point the forward from the
callback will WARN about forwarding an enqueued timer.
Now, conceptually its easy to detect if you're before or after the fwd
by comparing the expiration time against the current time. Of course,
that's expensive (and racy) because we don't have the current time.
Alternatively one could cache this state inside the timer, but then
everybody pays the overhead of maintaining this extra state, and that
is undesired.
The only other option that I could see is the external timer_active
variable, which I tried to kill before. I would love a nicer interface
for this seemingly simple 'problem' but alas.
Fixes: 272325c482 ("perf: Fix mux_interval hrtimer wreckage")
Fixes: 77a4d1a1b9 ("sched: Cleanup bandwidth timers")
Cc: pjt@google.com
Cc: tglx@linutronix.de
Cc: klamm@yandex-team.ru
Cc: mingo@kernel.org
Cc: bsegall@google.com
Cc: hpa@zytor.com
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150514102311.GX21418@twins.programming.kicks-ass.net
The term "ftrace" is really the infrastructure of the function hooks,
and not the trace events. Rename ftrace_event.h to trace_events.h to
represent the trace_event infrastructure and decouple the term ftrace
from it.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Thomas stumbled over the hrtimer_forward_now() in
perf_event_mux_interval_ms_store() and noticed its broken-ness.
You cannot just change the expiry time of an active timer, it will
destroy the red-black tree order and cause havoc.
Change it to (re)start the timer instead, (re)starting a timer will
dequeue and enqueue a timer and therefore preserve rb-tree order.
Since we cannot enqueue remotely, wrap the thing in
cpu_function_call(), this however mandates that we restrict ourselves
to online cpus. Also serialize the entire setting so we don't get
multiple concurrent threads trying to update to different values.
Also fix a problem in perf_mux_hrtimer_restart(), checking against
hrtimer_active() can actually loose us the timer when timer->state ==
HRTIMER_STATE_CALLBACK and the callback has already decided NORESTART.
Furthermore it doesn't make any sense to test
hrtimer_callback_running() when we already tested hrtimer_active(),
but with the above change, we explicitly must call it when
callback_running.
Lastly, rename a few functions:
s/perf_cpu_hrtimer_/perf_mux_hrtimer_/ -- because I could not find
the mux timer function
s/\<hr\>/timer/ -- because that's the normal way of calling things.
Fixes: 62b8563979 ("perf: Add sysfs entry to adjust multiplexing interval per PMU")
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150415095011.863052571@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
hrtimer_start() does not longer defer already expired timers to the
softirq. Get rid of the __hrtimer_start_range_ns() invocation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20150414203502.452104213@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull networking updates from David Miller:
1) Add BQL support to via-rhine, from Tino Reichardt.
2) Integrate SWITCHDEV layer support into the DSA layer, so DSA drivers
can support hw switch offloading. From Floria Fainelli.
3) Allow 'ip address' commands to initiate multicast group join/leave,
from Madhu Challa.
4) Many ipv4 FIB lookup optimizations from Alexander Duyck.
5) Support EBPF in cls_bpf classifier and act_bpf action, from Daniel
Borkmann.
6) Remove the ugly compat support in ARP for ugly layers like ax25,
rose, etc. And use this to clean up the neigh layer, then use it to
implement MPLS support. All from Eric Biederman.
7) Support L3 forwarding offloading in switches, from Scott Feldman.
8) Collapse the LOCAL and MAIN ipv4 FIB tables when possible, to speed
up route lookups even further. From Alexander Duyck.
9) Many improvements and bug fixes to the rhashtable implementation,
from Herbert Xu and Thomas Graf. In particular, in the case where
an rhashtable user bulk adds a large number of items into an empty
table, we expand the table much more sanely.
10) Don't make the tcp_metrics hash table per-namespace, from Eric
Biederman.
11) Extend EBPF to access SKB fields, from Alexei Starovoitov.
12) Split out new connection request sockets so that they can be
established in the main hash table. Much less false sharing since
hash lookups go direct to the request sockets instead of having to
go first to the listener then to the request socks hashed
underneath. From Eric Dumazet.
13) Add async I/O support for crytpo AF_ALG sockets, from Tadeusz Struk.
14) Support stable privacy address generation for RFC7217 in IPV6. From
Hannes Frederic Sowa.
15) Hash network namespace into IP frag IDs, also from Hannes Frederic
Sowa.
16) Convert PTP get/set methods to use 64-bit time, from Richard
Cochran.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1816 commits)
fm10k: Bump driver version to 0.15.2
fm10k: corrected VF multicast update
fm10k: mbx_update_max_size does not drop all oversized messages
fm10k: reset head instead of calling update_max_size
fm10k: renamed mbx_tx_dropped to mbx_tx_oversized
fm10k: update xcast mode before synchronizing multicast addresses
fm10k: start service timer on probe
fm10k: fix function header comment
fm10k: comment next_vf_mbx flow
fm10k: don't handle mailbox events in iov_event path and always process mailbox
fm10k: use separate workqueue for fm10k driver
fm10k: Set PF queues to unlimited bandwidth during virtualization
fm10k: expose tx_timeout_count as an ethtool stat
fm10k: only increment tx_timeout_count in Tx hang path
fm10k: remove extraneous "Reset interface" message
fm10k: separate PF only stats so that VF does not display them
fm10k: use hw->mac.max_queues for stats
fm10k: only show actual queues, not the maximum in hardware
fm10k: allow creation of VLAN on default vid
fm10k: fix unused warnings
...
For counters that generate AUX data that is bound to the context of a
running task, such as instruction tracing, the decoder needs to know
exactly which task is running when the event is first scheduled in,
before the first sched_switch. The decoder's need to know this stems
from the fact that instruction flow trace decoding will almost always
require program's object code in order to reconstruct said flow and
for that we need at least its pid/tid in the perf stream.
To single out such instruction tracing pmus, this patch introduces
ITRACE PMU capability. The reason this is not part of RECORD_AUX
record is that not all pmus capable of generating AUX data need this,
and the opposite is *probably* also true.
While sched_switch covers for most cases, there are two problems with it:
the consumer will need to process events out of order (that is, having
found RECORD_AUX, it will have to skip forward to the nearest sched_switch
to figure out which task it was, then go back to the actual trace to
decode it) and it completely misses the case when the tracing is enabled
and disabled before sched_switch, for example, via PERF_EVENT_IOC_DISABLE.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-15-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When AUX area gets a certain amount of new data, we want to wake up
userspace to collect it. This adds a new control to specify how much
data will cause a wakeup. This is then passed down to pmu drivers via
output handle's "wakeup" field, so that the driver can find the nearest
point where it can generate an interrupt.
We repurpose __reserved_2 in the event attribute for this, even though
it was never checked to be zero before, aux_watermark will only matter
for new AUX-aware code, so the old code should still be fine.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-10-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This adds support for overwrite mode in the AUX area, which means "keep
collecting data till you're stopped", turning AUX area into a circular
buffer, where new data overwrites old data. It does not depend on data
buffer's overwrite mode, so that it doesn't lose sideband data that is
instrumental for processing AUX data.
Overwrite mode is enabled at mapping AUX area read only. Even though
aux_tail in the buffer's user page might be user writable, it will be
ignored in this mode.
A PERF_RECORD_AUX with PERF_AUX_FLAG_OVERWRITE set is written to the perf
data stream every time an event writes new data to the AUX area. The pmu
driver might not be able to infer the exact beginning of the new data in
each snapshot, some drivers will only provide the tail, which is
aux_offset + aux_size in the AUX record. Consumer has to be able to tell
the new data from the old one, for example, by means of time stamps if
such are provided in the trace.
Consumer is also responsible for disabling any events that might write
to the AUX area (thus potentially racing with the consumer) before
collecting the data.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-9-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
For pmus that wish to write data to ring buffer's AUX area, provide
perf_aux_output_{begin,end}() calls to initiate/commit data writes,
similarly to perf_output_{begin,end}. These also use the same output
handle structure. Also, similarly to software counterparts, these
will direct inherited events' output to parents' ring buffers.
After the perf_aux_output_begin() returns successfully, handle->size
is set to the maximum amount of data that can be written wrt aux_tail
pointer, so that no data that the user hasn't seen will be overwritten,
therefore this should always be called before hardware writing is
enabled. On success, this will return the pointer to pmu driver's
private structure allocated for this aux area by pmu::setup_aux. Same
pointer can also be retrieved using perf_get_aux() while hardware
writing is enabled.
PMU driver should pass the actual amount of data written as a parameter
to perf_aux_output_end(). All hardware writes should be completed and
visible before this one is called.
Additionally, perf_aux_output_skip() will adjust output handle and
aux_head in case some part of the buffer has to be skipped over to
maintain hardware's alignment constraints.
Nested writers are forbidden and guards are in place to catch such
attempts.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-8-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When there's new data in the AUX space, output a record indicating its
offset and size and a set of flags, such as PERF_AUX_FLAG_TRUNCATED, to
mean the described data was truncated to fit in the ring buffer.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-7-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Usually, pmus that do, for example, instruction tracing, would only ever
be able to have one event per task per cpu (or per perf_event_context). For
such pmus it makes sense to disallow creating conflicting events early on,
so as to provide consistent behavior for the user.
This patch adds a pmu capability that indicates such constraint on event
creation.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1422613866-113186-1-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
For pmus that don't support scatter-gather for AUX data in hardware, it
might still make sense to implement software double buffering to avoid
losing data while the user is reading data out. For this purpose, add
a pmu capability that guarantees multiple high-order chunks for AUX buffer,
so that the pmu driver can do switchover tricks.
To make use of this feature, add PERF_PMU_CAP_AUX_SW_DOUBLEBUF to your
pmu's capability mask. This will make the ring buffer AUX allocation code
ensure that the biggest high order allocation for the aux buffer pages is
no bigger than half of the total requested buffer size, thus making sure
that the buffer has at least two high order allocations.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-5-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some pmus (such as BTS or Intel PT without multiple-entry ToPA capability)
don't support scatter-gather and will prefer larger contiguous areas for
their output regions.
This patch adds a new pmu capability to request higher order allocations.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-4-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch introduces "AUX space" in the perf mmap buffer, intended for
exporting high bandwidth data streams to userspace, such as instruction
flow traces.
AUX space is a ring buffer, defined by aux_{offset,size} fields in the
user_page structure, and read/write pointers aux_{head,tail}, which abide
by the same rules as data_* counterparts of the main perf buffer.
In order to allocate/mmap AUX, userspace needs to set up aux_offset to
such an offset that will be greater than data_offset+data_size and
aux_size to be the desired buffer size. Both need to be page aligned.
Then, same aux_offset and aux_size should be passed to mmap() call and
if everything adds up, you should have an AUX buffer as a result.
Pages that are mapped into this buffer also come out of user's mlock
rlimit plus perf_event_mlock_kb allowance.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-3-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Currently, the actual perf ring buffer is one page into the mmap area,
following the user page and the userspace follows this convention. This
patch adds data_{offset,size} fields to user_page that can be used by
userspace instead for locating perf data in the mmap area. This is also
helpful when mapping existing or shared buffers if their size is not
known in advance.
Right now, it is made to follow the existing convention that
data_offset == PAGE_SIZE and
data_offset + data_size == mmap_size.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kaixu Xia <kaixu.xia@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: kan.liang@intel.com
Cc: markus.t.metzger@intel.com
Cc: mathieu.poirier@linaro.org
Link: http://lkml.kernel.org/r/1421237903-181015-2-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
BPF programs, attached to kprobes, provide a safe way to execute
user-defined BPF byte-code programs without being able to crash or
hang the kernel in any way. The BPF engine makes sure that such
programs have a finite execution time and that they cannot break
out of their sandbox.
The user interface is to attach to a kprobe via the perf syscall:
struct perf_event_attr attr = {
.type = PERF_TYPE_TRACEPOINT,
.config = event_id,
...
};
event_fd = perf_event_open(&attr,...);
ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);
'prog_fd' is a file descriptor associated with BPF program
previously loaded.
'event_id' is an ID of the kprobe created.
Closing 'event_fd':
close(event_fd);
... automatically detaches BPF program from it.
BPF programs can call in-kernel helper functions to:
- lookup/update/delete elements in maps
- probe_read - wraper of probe_kernel_read() used to access any
kernel data structures
BPF programs receive 'struct pt_regs *' as an input ('struct pt_regs' is
architecture dependent) and return 0 to ignore the event and 1 to store
kprobe event into the ring buffer.
Note, kprobes are a fundamentally _not_ a stable kernel ABI,
so BPF programs attached to kprobes must be recompiled for
every kernel version and user must supply correct LINUX_VERSION_CODE
in attr.kern_version during bpf_prog_load() call.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1427312966-8434-4-git-send-email-ast@plumgrid.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While thinking on the whole clock discussion it occurred to me we have
two distinct uses of time:
1) the tracking of event/ctx/cgroup enabled/running/stopped times
which includes the self-monitoring support in struct
perf_event_mmap_page.
2) the actual timestamps visible in the data records.
And we've been conflating them.
The first is all about tracking time deltas, nobody should really care
in what time base that happens, its all relative information, as long
as its internally consistent it works.
The second however is what people are worried about when having to
merge their data with external sources. And here we have the
discussion on MONOTONIC vs MONOTONIC_RAW etc..
Where MONOTONIC is good for correlating between machines (static
offset), MONOTNIC_RAW is required for correlating against a fixed rate
hardware clock.
This means configurability; now 1) makes that hard because it needs to
be internally consistent across groups of unrelated events; which is
why we had to have a global perf_clock().
However, for 2) it doesn't really matter, perf itself doesn't care
what it writes into the buffer.
The below patch makes the distinction between these two cases by
adding perf_event_clock() which is used for the second case. It
further makes this configurable on a per-event basis, but adds a few
sanity checks such that we cannot combine events with different clocks
in confusing ways.
And since we then have per-event configurability we might as well
retain the 'legacy' behaviour as a default.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While looking at some fuzzer output I noticed that we do not hold any
locks on leader->ctx and therefore the sibling_list iteration is
unsafe.
Acquire the relevant ctx->mutex before calling into the pmu specific
code.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Link: http://lkml.kernel.org/r/20150225151639.GL5029@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vince reported a watchdog lockup like:
[<ffffffff8115e114>] perf_tp_event+0xc4/0x210
[<ffffffff810b4f8a>] perf_trace_lock+0x12a/0x160
[<ffffffff810b7f10>] lock_release+0x130/0x260
[<ffffffff816c7474>] _raw_spin_unlock_irqrestore+0x24/0x40
[<ffffffff8107bb4d>] do_send_sig_info+0x5d/0x80
[<ffffffff811f69df>] send_sigio_to_task+0x12f/0x1a0
[<ffffffff811f71ce>] send_sigio+0xae/0x100
[<ffffffff811f72b7>] kill_fasync+0x97/0xf0
[<ffffffff8115d0b4>] perf_event_wakeup+0xd4/0xf0
[<ffffffff8115d103>] perf_pending_event+0x33/0x60
[<ffffffff8114e3fc>] irq_work_run_list+0x4c/0x80
[<ffffffff8114e448>] irq_work_run+0x18/0x40
[<ffffffff810196af>] smp_trace_irq_work_interrupt+0x3f/0xc0
[<ffffffff816c99bd>] trace_irq_work_interrupt+0x6d/0x80
Which is caused by an irq_work generating new irq_work and therefore
not allowing forward progress.
This happens because processing the perf irq_work triggers another
perf event (tracepoint stuff) which in turn generates an irq_work ad
infinitum.
Avoid this by raising the recursion counter in the irq_work -- which
effectively disables all software events (including tracepoints) from
actually triggering again.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20150219170311.GH21418@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit:
a83fe28e2e ("perf: Fix put_event() ctx lock")
changed the locking logic in put_event() by replacing mutex_lock_nested()
with perf_event_ctx_lock_nested(), but didn't fix the subsequent
mutex_unlock() with a correct counterpart, perf_event_ctx_unlock().
Contexts are thus leaked as a result of incremented refcount
in perf_event_ctx_lock_nested().
Signed-off-by: Leon Yu <chianglungyu@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Fixes: a83fe28e2e ("perf: Fix put_event() ctx lock")
Link: http://lkml.kernel.org/r/1424954613-5034-1-git-send-email-chianglungyu@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This reverts commit 74390aa556 ("perf: Remove the extra validity check
on nr_pages")
nr_pages equals to number of pages - 1 in perf_mmap. So nr_pages = 0 is
valid.
So the nr_pages != 0 && !is_power_of_2(nr_pages) are all
needed for checking. Otherwise, for example, perf test 6 failed.
# perf test 6
6: x86 rdpmc test :Error:
mmap() syscall returned with (Invalid argument)
FAILED!
Signed-off-by: Kan Liang <kan.liang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1425280466-7830-1-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add support for task events as well as system-wide events. This change
has a big impact on the way that we gather LLC occupancy values in
intel_cqm_event_read().
Currently, for system-wide (per-cpu) events we defer processing to
userspace which knows how to discard all but one cpu result per package.
Things aren't so simple for task events because we need to do the value
aggregation ourselves. To do this, we defer updating the LLC occupancy
value in event->count from intel_cqm_event_read() and do an SMP
cross-call to read values for all packages in intel_cqm_event_count().
We need to ensure that we only do this for one task event per cache
group, otherwise we'll report duplicate values.
If we're a system-wide event we want to fallback to the default
perf_event_count() implementation. Refactor this into a common function
so that we don't duplicate the code.
Also, introduce PERF_TYPE_INTEL_CQM, since we need a way to track an
event's task (if the event isn't per-cpu) inside of the Intel CQM PMU
driver. This task information is only availble in the upper layers of
the perf infrastructure.
Other perf backends stash the target task in event->hw.*target so we
need to do something similar. The task is used to determine whether
events should share a cache group and an RMID.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kanaka Juvva <kanaka.d.juvva@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: linux-api@vger.kernel.org
Link: http://lkml.kernel.org/r/1422038748-21397-8-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The Intel QoS PMU needs to know whether an event is part of a cgroup
during ->event_init(), because tasks in the same cgroup share a
monitoring ID.
Move the cgroup initialisation before calling into the PMU driver.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kanaka Juvva <kanaka.d.juvva@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Link: http://lkml.kernel.org/r/1422038748-21397-4-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
For PMU drivers that record per-package counters, the ->count variable
cannot be used to record an accurate aggregated value, since it's not
possible to perform SMP cross-calls to cpus on other packages from the
context in which we update ->count.
Introduce a new optional ->count() accessor function that can be used to
customize how values are collected. If a PMU driver doesn't provide a
->count() function, we fallback to the existing code.
There is necessarily a window of staleness with this approach because
the task that generated the counter value may not have been scheduled by
the cpu recently.
An alternative and more complex approach would be to use a hrtimer to
periodically refresh the values from a more permissive scheduling
context. So, we're trading off complexity for accuracy.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kanaka Juvva <kanaka.d.juvva@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Link: http://lkml.kernel.org/r/1422038748-21397-3-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Move perf_cgroup_from_task() from kernel/events/ to include/linux/ along
with the necessary struct definitions, so that it can be used by the PMU
code.
When the upcoming Intel Cache Monitoring PMU driver assigns monitoring
IDs to perf events, it needs to be able to check whether any two
monitoring events overlap (say, a cgroup and task event), which means we
need to be able to lookup the cgroup associated with a task (if any).
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kanaka Juvva <kanaka.d.juvva@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Link: http://lkml.kernel.org/r/1422038748-21397-2-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
User visible:
- 'perf trace': Allow mixing with tracepoints and suppressing plain syscalls
(Arnaldo Carvalho de Melo)
Infrastructure:
- Kconfig beachhead (Jiri Olsa)
- Simplify nr_pages validity (Kaixu Xia)
- Fixup header positioning in 'perf list' (Yunlong Song)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
User visible changes:
- No need to explicitely enable evsels for workload started from perf, let it
be enabled via perf_event_attr.enable_on_exec, removing some events that take
place in the 'perf trace' before a workload is really started by it.
(Arnaldo Carvalho de Melo)
- Fix to handle optimized not-inlined functions in 'perf probe' (Masami Hiramatsu)
- Update 'perf probe' man page (Masami Hiramatsu)
- 'perf trace': Allow mixing with tracepoints and suppressing plain syscalls
(Arnaldo Carvalho de Melo)
Infrastructure changes:
- Introduce {trace_seq_do,event_format_}_fprintf functions to allow
a default tracepoint field list printer to be used in tools that allows
redirecting output to a file. (Arnaldo Carvalho de Melo)
- The man page for pthread_attr_set_affinity_np states that _GNU_SOURCE
must be defined before pthread.h, do it to fix the build in some
systems (Josh Boyer)
- Cleanups in 'perf buildid-cache' (Masami Hiramatsu)
- Fix dso cache test case (Namhyung Kim)
- Do Not rely on dso__data_read_offset() to open DSO (Namhyung Kim)
- Make perf aware of tracefs (Steven Rostedt).
- Fix build by defining STT_GNU_IFUNC for glibc 2.9 and older (Vinson Lee)
- AArch64 symbol resolution fixes (Victor Kamensky)
- Kconfig beachhead (Jiri Olsa)
- Simplify nr_pages validity (Kaixu Xia)
- Fixup header positioning in 'perf list' (Yunlong Song)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use event->attr.branch_sample_type to replace
intel_pmu_needs_lbr_smpl() for avoiding duplicated code that
implicitly enables the LBR.
Currently, branch stack can be enabled by user explicitly requesting
branch sampling or implicit branch sampling to correct PEBS skid.
For user explicitly requested branch sampling, the branch_sample_type
is explicitly set by user. For PEBS case, the branch_sample_type is also
implicitly set to PERF_SAMPLE_BRANCH_ANY in x86_pmu_hw_config.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: eranian@google.com
Cc: jolsa@redhat.com
Link: http://lkml.kernel.org/r/1415156173-10035-11-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If two tasks were both forked from the same parent task, Events in
their perf task contexts can be the same. Perf core may leave out
switching the perf event contexts.
Previous patch inroduces pmu specific data. The data is for saving
the LBR stack, it is task specific. So we need to switch the data
even when context switch is optimized out.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: eranian@google.com
Cc: jolsa@redhat.com
Link: http://lkml.kernel.org/r/1415156173-10035-7-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
