Eric Paris reported that commit
f685ceacab causes boot time
PREEMPT_DEBUG complaints.
[ 4.590699] BUG: using smp_processor_id() in preemptible [00000000] code: rmmod/1314
[ 4.593043] caller is task_hot+0x86/0xd0
Since kthread_bind() messes with scheduler internals, move the
body to sched.c, and lock the runqueue.
Reported-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Tested-by: Eric Paris <eparis@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1256813310.7574.3.camel@marge.simson.net>
[ v2: fix !SMP build and clean up ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf tools: Remove -Wcast-align
perf tools: Fix compatibility with libelf 0.8 and autodetect
perf events: Don't generate events for the idle task when exclude_idle is set
perf events: Fix swevent hrtimer sampling by keeping track of remaining time when enabling/disabling swevent hrtimers
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: Remove cpu arg from the rb_time_stamp() function
tracing: Fix comment typo and documentation example
tracing: Fix trace_seq_printf() return value
tracing: Update *ppos instead of filp->f_pos
Very long RCU read-side critical sections (50 milliseconds or
so) can cause a race between force_quiescent_state() and
rcu_start_gp() as follows on kernel builds with multi-level
rcu_node hierarchies:
1. CPU 0 calls force_quiescent_state(), sees that there is a
grace period in progress, and acquires ->fsqlock.
2. CPU 1 detects the end of the grace period, and so
cpu_quiet_msk_finish() sets rsp->completed to rsp->gpnum.
This operation is carried out under the root rnp->lock,
but CPU 0 has not yet acquired that lock. Note that
rsp->signaled is still RCU_SAVE_DYNTICK from the last
grace period.
3. CPU 1 calls rcu_start_gp(), but no one wants a new grace
period, so it drops the root rnp->lock and returns.
4. CPU 0 acquires the root rnp->lock and picks up rsp->completed
and rsp->signaled, then drops rnp->lock. It then enters the
RCU_SAVE_DYNTICK leg of the switch statement.
5. CPU 2 invokes call_rcu(), and now needs a new grace period.
It calls rcu_start_gp(), which acquires the root rnp->lock, sets
rsp->signaled to RCU_GP_INIT (too bad that CPU 0 is already in
the RCU_SAVE_DYNTICK leg of the switch statement!) and starts
initializing the rcu_node hierarchy. If there are multiple
levels to the hierarchy, it will drop the root rnp->lock and
initialize the lower levels of the hierarchy.
6. CPU 0 notes that rsp->completed has not changed, which permits
both CPU 2 and CPU 0 to try updating it concurrently. If CPU 0's
update prevails, later calls to force_quiescent_state() can
count old quiescent states against the new grace period, which
can in turn result in premature ending of grace periods.
Not good.
This patch adds an RCU_GP_IDLE state for rsp->signaled that is
set initially at boot time and any time a grace period ends.
This prevents CPU 0 from getting into the workings of
force_quiescent_state() in step 4. Additional locking and
checks prevent the concurrent update of rsp->signaled in step 6.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1256742889199-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Ingo triggered the following warning:
WARNING: at lib/debugobjects.c:255 debug_print_object+0x42/0x50()
Hardware name: System Product Name
ODEBUG: init active object type: timer_list
Modules linked in:
Pid: 2619, comm: dmesg Tainted: G W 2.6.32-rc5-tip+ #5298
Call Trace:
[<81035443>] warn_slowpath_common+0x6a/0x81
[<8120e483>] ? debug_print_object+0x42/0x50
[<81035498>] warn_slowpath_fmt+0x29/0x2c
[<8120e483>] debug_print_object+0x42/0x50
[<8120ec2a>] __debug_object_init+0x279/0x2d7
[<8120ecb3>] debug_object_init+0x13/0x18
[<810409d2>] init_timer_key+0x17/0x6f
[<81041526>] free_uid+0x50/0x6c
[<8104ed2d>] put_cred_rcu+0x61/0x72
[<81067fac>] rcu_do_batch+0x70/0x121
debugobjects warns about an enqueued timer being initialized. If
CONFIG_USER_SCHED=y the user management code uses delayed work to
remove the user from the hash table and tear down the sysfs objects.
free_uid is called from RCU and initializes/schedules delayed work if
the usage count of the user_struct is 0. The init/schedule happens
outside of the uidhash_lock protected region which allows a concurrent
caller of find_user() to reference the about to be destroyed
user_struct w/o preventing the work from being scheduled. If the next
free_uid call happens before the work timer expired then the active
timer is initialized and the work scheduled again.
The race was introduced in commit 5cb350ba (sched: group scheduling,
sysfs tunables) and made more prominent by commit 3959214f (sched:
delayed cleanup of user_struct)
Move the init/schedule_delayed_work inside of the uidhash_lock
protected region to prevent the race.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Paul E. McKenney <paulmck@us.ibm.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: stable@kernel.org
I got a boot crash when forcing cpumasks offstack on 32 bit,
because find_new_ilb() returned 3 on my UP system (nohz.cpu_mask
wasn't zeroed).
AFAICT the others need to be zeroed too: only
nohz.ilb_grp_nohz_mask is initialized before use.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <200911022037.21282.rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
sched: move rq_weight data array out of .percpu
percpu: allow pcpu_alloc() to be called with IRQs off
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-param-fixes:
param: fix setting arrays of bool
param: fix NULL comparison on oom
param: fix lots of bugs with writing charp params from sysfs, by leaking mem.
* 'hwpoison-2.6.32' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6:
HWPOISON: fix invalid page count in printk output
HWPOISON: Allow schedule_on_each_cpu() from keventd
HWPOISON: fix/proc/meminfo alignment
HWPOISON: fix oops on ksm pages
HWPOISON: Fix page count leak in hwpoison late kill in do_swap_page
HWPOISON: return early on non-LRU pages
HWPOISON: Add brief hwpoison description to Documentation
HWPOISON: Clean up PR_MCE_KILL interface
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futex: Move drop_futex_key_refs out of spinlock'ed region
rcu: Fix TREE_PREEMPT_RCU CPU_HOTPLUG bad-luck hang
rcu: Stopgap fix for synchronize_rcu_expedited() for TREE_PREEMPT_RCU
rcu: Prevent RCU IPI storms in presence of high call_rcu() load
futex: Check for NULL keys in match_futex
futex: Handle spurious wake up
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf timechart: Improve the visual appearance of scheduler delays
perf timechart: Fix the wakeup-arrows that point to non-visible processes
perf top: Fix --delay_secs 0 division by zero
perf tools: Bump version to 0.0.2
perf_event: Adjust frequency and unthrottle for non-group-leader events
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Do less agressive buddy clearing
sched: Disable SD_PREFER_LOCAL for MC/CPU domains
Having ->procname but not ->proc_handler is valid when PROC_SYSCTL=n,
people use such combination to reduce ifdefs with non-standard handlers.
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=14408
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reported-by: Peter Teoh <htmldeveloper@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 02b51df1b0 (proc connector: add
event for process becoming session leader) we have the following warning:
Badness at kernel/softirq.c:143
[...]
Krnl PSW : 0404c00180000000 00000000001481d4 (local_bh_enable+0xb0/0xe0)
[...]
Call Trace:
([<000000013fe04100>] 0x13fe04100)
[<000000000048a946>] sk_filter+0x9a/0xd0
[<000000000049d938>] netlink_broadcast+0x2c0/0x53c
[<00000000003ba9ae>] cn_netlink_send+0x272/0x2b0
[<00000000003baef0>] proc_sid_connector+0xc4/0xd4
[<0000000000142604>] __set_special_pids+0x58/0x90
[<0000000000159938>] sys_setsid+0xb4/0xd8
[<00000000001187fe>] sysc_noemu+0x10/0x16
[<00000041616cb266>] 0x41616cb266
The warning is
---> WARN_ON_ONCE(in_irq() || irqs_disabled());
The network code must not be called with disabled interrupts but
sys_setsid holds the tasklist_lock with spinlock_irq while calling the
connector.
After a discussion we agreed that we can move proc_sid_connector from
__set_special_pids to sys_setsid.
We also agreed that it is sufficient to change the check from
task_session(curr) != pid into err > 0, since if we don't change the
session, this means we were already the leader and return -EPERM.
One last thing:
There is also daemonize(), and some people might want to get a
notification in that case. Since daemonize() is only needed if a user
space does kernel_thread this does not look important (and there seems
to be no consensus if this connector should be called in daemonize). If
we really want this, we can add proc_sid_connector to daemonize() in an
additional patch (Scott?)
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Scott James Remnant <scott@ubuntu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix find_probe_event() to compare both of event-name and
event-group. Without this fix, kprobe-tracer overwrites existing
same event-name probe even if its group-name is different.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
LKML-Reference: <20091027204244.30545.27516.stgit@harusame>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We create a dummy struct kernel_param on the stack for parsing each
array element, but we didn't initialize the flags word. This matters
for arrays of type "bool", where the flag indicates if it really is
an array of bools or unsigned int (old-style).
Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
kp->arg is always true: it's the contents of that pointer we care about.
Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
e180a6b775 "param: fix charp parameters set via sysfs" fixed the case
where charp parameters written via sysfs were freed, leaving drivers
accessing random memory.
Unfortunately, storing a flag in the kparam struct was a bad idea: it's
rodata so setting it causes an oops on some archs. But that's not all:
1) module_param_array() on charp doesn't work reliably, since we use an
uninitialized temporary struct kernel_param.
2) there's a fundamental race if a module uses this parameter and then
it's changed: they will still access the old, freed, memory.
The simplest fix (ie. for 2.6.32) is to never free the memory. This
prevents all these problems, at cost of a memory leak. In practice, there
are only 18 places where a charp is writable via sysfs, and all are
root-only writable.
Reported-by: Takashi Iwai <tiwai@suse.de>
Cc: Sitsofe Wheeler <sitsofe@yahoo.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
The requeue_pi path doesn't use unqueue_me() (and the racy lock_ptr ==
NULL test) nor does it use the wake_list of futex_wake() which where
the reason for commit 41890f2 (futex: Handle spurious wake up)
See debugging discussing on LKML Message-ID: <4AD4080C.20703@us.ibm.com>
The changes in this fix to the wait_requeue_pi path were considered to
be a likely unecessary, but harmless safety net. But it turns out that
due to the fact that for unknown $@#!*( reasons EWOULDBLOCK is defined
as EAGAIN we built an endless loop in the code path which returns
correctly EWOULDBLOCK.
Spurious wakeups in wait_requeue_pi code path are unlikely so we do
the easy solution and return EWOULDBLOCK^WEAGAIN to user space and let
it deal with the spurious wakeup.
Cc: Darren Hart <dvhltc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: John Stultz <johnstul@linux.vnet.ibm.com>
Cc: Dinakar Guniguntala <dino@in.ibm.com>
LKML-Reference: <4AE23C74.1090502@us.ibm.com>
Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add two more software events that are common to many cpus.
Alignment faults: When a load or store is not aligned properly.
Emulation faults: When an instruction is emulated in software.
Both cause a very significant slowdown (100x or worse), so identifying and
fixing them is very important.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The cpu argument is not used inside the rb_time_stamp() function.
Plus fix a typo.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091023233647.118547500@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Trivial patch to fix a documentation example and to fix a
comment.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091023233646.871719877@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
trace_seq_printf() return value is a little ambiguous. It
currently returns the length of the space available in the
buffer. printf usually returns the amount written. This is not
adequate here, because:
trace_seq_printf(s, "");
is perfectly legal, and returning 0 would indicate that it
failed.
We can always see the amount written by looking at the before
and after values of s->len. This is not quite the same use as
printf. We only care if the string was successfully written to
the buffer or not.
Make trace_seq_printf() return 0 if the trace oversizes the
buffer's free space, 1 otherwise.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091023233646.631787612@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Instead of directly updating filp->f_pos we should update the *ppos
argument. The filp->f_pos gets updated within the file_pos_write()
function called from sys_write().
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091023233646.399670810@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch restores the effectiveness of LAST_BUDDY in preventing
pgsql+oltp from collapsing due to wakeup preemption. It also
switches LAST_BUDDY to exclusively do what it does best, namely
mitigate the effects of aggressive wakeup preemption, which
improves vmark throughput markedly, and restores mysql+oltp
scalability.
Since buddies are about scalability, enable them beginning at the
point where we begin expanding sched_latency, namely
sched_nr_latency. Previously, buddies were cleared aggressively,
which seriously reduced their effectiveness. Not clearing
aggressively however, produces a small drop in mysql+oltp
throughput immediately after peak, indicating that LAST_BUDDY is
actually doing some harm. This is right at the point where X on the
desktop in competition with another load wants low latency service.
Ergo, do not enable until we need to scale.
To mitigate latency induced by buddies, or by a task just missing
wakeup preemption, check latency at tick time.
Last hunk prevents buddies from stymieing BALANCE_NEWIDLE via
CACHE_HOT_BUDDY.
Supporting performance tests:
tip = v2.6.32-rc5-1497-ga525b32
tipx = NO_GENTLE_FAIR_SLEEPERS NEXT_BUDDY granularity knobs = 31 knobs + 31 buddies
tip+x = NO_GENTLE_FAIR_SLEEPERS granularity knobs = 31 knobs
(Three run averages except where noted.)
vmark:
------
tip 108466 messages per second
tip+ 125307 messages per second
tip+x 125335 messages per second
tipx 117781 messages per second
2.6.31.3 122729 messages per second
mysql+oltp:
-----------
clients 1 2 4 8 16 32 64 128 256
..........................................................................................
tip 9949.89 18690.20 34801.24 34460.04 32682.88 30765.97 28305.27 25059.64 19548.08
tip+ 10013.90 18526.84 34900.38 34420.14 33069.83 32083.40 30578.30 28010.71 25605.47
tipx 9698.71 18002.70 34477.56 33420.01 32634.30 31657.27 29932.67 26827.52 21487.18
2.6.31.3 8243.11 18784.20 34404.83 33148.38 31900.32 31161.90 29663.81 25995.94 18058.86
pgsql+oltp:
-----------
clients 1 2 4 8 16 32 64 128 256
..........................................................................................
tip 13686.37 26609.25 51934.28 51347.81 49479.51 45312.65 36691.91 26851.57 24145.35
tip+ (1x) 13907.85 27135.87 52951.98 52514.04 51742.52 50705.43 49947.97 48374.19 46227.94
tip+x 13906.78 27065.81 52951.19 52542.59 52176.11 51815.94 50838.90 49439.46 46891.00
tipx 13742.46 26769.81 52351.99 51891.73 51320.79 50938.98 50248.65 48908.70 46553.84
2.6.31.3 13815.35 26906.46 52683.34 52061.31 51937.10 51376.80 50474.28 49394.47 47003.25
Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Getting samples for the idle task is often not interesting, so
don't generate them when exclude_idle is set for the event in
question.
Signed-off-by: Søren Sandmann Pedersen <sandmann@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <ye8pr8fmlq7.fsf@camel16.daimi.au.dk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Make the hrtimer based events work for sysprof.
Whenever a swevent is scheduled out, the hrtimer is canceled.
When it is scheduled back in, the timer is restarted. This
happens every scheduler tick, which means the timer never
expired because it was getting repeatedly restarted over and
over with the same period.
To fix that, save the remaining time when disabling; when
reenabling, use that saved time as the period instead of the
user-specified sampling period.
Also, move the starting and stopping of the hrtimers to helper
functions instead of duplicating the code.
Signed-off-by: Søren Sandmann Pedersen <sandmann@redhat.com>
LKML-Reference: <ye8vdi7mluz.fsf@camel16.daimi.au.dk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conflicts:
tools/perf/Makefile
Merge reason:
- fix the conflict
- pick up the pr_*() infrastructure to queue up dependent patch
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Increase TEST_SUSPEND_SECONDS to 10 so the warning in
suspend_test_finish() doesn't annoy the users of slower systems so much.
Also, make the warning print the suspend-resume cycle time, so that we
know why the warning actually triggered.
Patch prepared during the hacking session at the Kernel Summit in Tokyo.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now when calling schedule_on_each_cpu() from keventd there
is a deadlock because it tries to schedule a work item on the current CPU
too. This happens via lru_add_drain_all() in hwpoison.
Just call the function for the current CPU in this case. This is actually
faster too.
Debugging with Fengguang Wu & Max Asbock
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Conflicts:
kernel/Makefile
kernel/trace/Makefile
kernel/trace/trace.h
samples/Makefile
Merge reason: We need to be uptodate with the perf events development
branch because we plan to rewrite the breakpoints API on top of
perf events.
When requeuing tasks from one futex to another, the reference held
by the requeued task to the original futex location needs to be
dropped eventually.
Dropping the reference may ultimately lead to a call to
"iput_final" and subsequently call into filesystem- specific code -
which may be non-atomic.
It is therefore safer to defer this drop operation until after the
futex_hash_bucket spinlock has been dropped.
Originally-From: Helge Bahmann <hcb@chaoticmind.net>
Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Cc: <stable@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dinakar Guniguntala <dino@in.ibm.com>
Cc: John Stultz <johnstul@linux.vnet.ibm.com>
Cc: Sven-Thorsten Dietrich <sdietrich@novell.com>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <4AD7A298.5040802@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* branch 'tty-fixes'
tty: use the new 'flush_delayed_work()' helper to do ldisc flush
workqueue: add 'flush_delayed_work()' to run and wait for delayed work
tty: Make flush_to_ldisc() locking more robust
If the following sequence of events occurs, then
TREE_PREEMPT_RCU will hang waiting for a grace period to
complete, eventually OOMing the system:
o A TREE_PREEMPT_RCU build of the kernel is booted on a system
with more than 64 physical CPUs present (32 on a 32-bit system).
Alternatively, a TREE_PREEMPT_RCU build of the kernel is booted
with RCU_FANOUT set to a sufficiently small value that the
physical CPUs populate two or more leaf rcu_node structures.
o A task is preempted in an RCU read-side critical section
while running on a CPU corresponding to a given leaf rcu_node
structure.
o All CPUs corresponding to this same leaf rcu_node structure
record quiescent states for the current grace period.
o All of these same CPUs go offline (hence the need for enough
physical CPUs to populate more than one leaf rcu_node structure).
This causes the preempted task to be moved to the root rcu_node
structure.
At this point, there is nothing left to cause the quiescent
state to be propagated up the rcu_node tree, so the current
grace period never completes.
The simplest fix, especially after considering the deadlock
possibilities, is to detect this situation when the last CPU is
offlined, and to set that CPU's ->qsmask bit in its leaf
rcu_node structure. This will cause the next invocation of
force_quiescent_state() to end the grace period.
Without this fix, this hang can be triggered in an hour or so on
some machines with rcutorture and random CPU onlining/offlining.
With this fix, these same machines pass a full 10 hours of this
sort of abuse.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <20091015162614.GA19131@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Américo Wang noticed that we have a locking imbalance in the
error paths of ftrace_profile_set_filter(), causing potential
leakage of event_mutex.
Also clean up other error codepaths related to event_mutex
while at it.
Plus fix an initialized variable in the subsystem filter code.
Reported-by: Américo Wang <xiyou.wangcong@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <2375c9f90910150247u5ccb8e2at58c764e385ffa490@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
- Add an ioctl to allocate a filter for a perf event.
- Free the filter when the associated perf event is to be freed.
- Do the filtering in perf_swevent_match().
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <4AD69546.8050401@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
"==" will always do a full match, and "~" will do a glob match.
In the future, we may add "=~" for regex match.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <4AD69528.3050309@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Change:
for_each_pred
for_each_subsystem
To:
for_each_subsystem
for_each_pred
This change also prepares for later patches.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <4AD69502.8060903@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Merge reason: to add event filter support we need the following
commits from the tracing tree:
3f6fe06: tracing/filters: Unify the regex parsing helpers
1889d20: tracing/filters: Provide basic regex support
737f453: tracing/filters: Cleanup useless headers
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* branch 'tty-fixes':
tty: use the new 'flush_delayed_work()' helper to do ldisc flush
workqueue: add 'flush_delayed_work()' to run and wait for delayed work
Make flush_to_ldisc properly handle parallel calls
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
oprofile: warn on freeing event buffer too early
oprofile: fix race condition in event_buffer free
lockdep: Use cpu_clock() for lockstat
It basically turns a delayed work into an immediate work, and then waits
for it to finish, thus allowing you to force (and wait for) an immediate
flush of a delayed work.
We'll want to use this in the tty layer to clean up tty_flush_to_ldisc().
Acked-by: Oleg Nesterov <oleg@redhat.com>
[ Fixed to use 'del_timer_sync()' as noted by Oleg ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If userspace tries to perform a requeue_pi on a non-requeue_pi waiter,
it will find the futex_q->requeue_pi_key to be NULL and OOPS.
Check for NULL in match_futex() instead of doing explicit NULL pointer
checks on all call sites. While match_futex(NULL, NULL) returning
false is a little odd, it's still correct as we expect valid key
references.
Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: Dinakar Guniguntala <dino@in.ibm.com>
CC: John Stultz <johnstul@us.ibm.com>
Cc: stable@kernel.org
LKML-Reference: <4AD60687.10306@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
set_cmdline_ftrace is a better match against what does this function:
apply a tracer name from the kernel command line.
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
We are using strncpy in the wrong way to copy the ftrace_graph_filter
boot param because we pass the buffer size instead of the max string
size it can contain (buffer size - 1). The end result might not be
NULL terminated as we are abusing the max string size.
Lets use strlcpy() instead.
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Yanmin reported a hackbench regression due to:
> commit de69a80be3
> Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Date: Thu Sep 17 09:01:20 2009 +0200
>
> sched: Stop buddies from hogging the system
I really liked de69a80b, and it affecting hackbench shows I wasn't
crazy ;-)
So hackbench is a multi-cast, with one sender spraying multiple
receivers, who in their turn don't spray back.
This would be exactly the scenario that patch 'cures'. Previously
we would not clear the last buddy after running the next task,
allowing the sender to get back to work sooner than it otherwise
ought to have been, increasing latencies for other tasks.
Now, since those receivers don't poke back, they don't enforce the
buddy relation, which means there's nothing to re-elect the sender.
Cure this by less agressively clearing the buddy stats. Only clear
buddies when they were not chosen. It should still avoid a buddy
sticking around long after its served its time.
Reported-by: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Mike Galbraith <efault@gmx.de>
LKML-Reference: <1255084986.8802.46.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Most of the syscalls metadata processing is done from arch.
But these operations are mostly generic accross archs. Especially now
that we have a common variable name that expresses the number of
syscalls supported by an arch: NR_syscalls, the only remaining bits
that need to reside in arch is the syscall nr to addr translation.
v2: Compare syscalls symbols only after the "sys" prefix so that we
avoid spurious mismatches with archs that have syscalls wrappers,
in which case syscalls symbols have "SyS" prefixed aliases.
(Reported by: Heiko Carstens)
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
The loop in perf_ctx_adjust_freq checks the frequency of sampling
event counters, and adjusts the event interval and unthrottles the
event if required, and resets the interrupt count for the event.
However, at present it only looks at group leaders.
This means that a sampling event that is not a group leader will
eventually get throttled, once its interrupt count reaches
sysctl_perf_event_sample_rate/HZ --- and that is guaranteed to
happen, if the event is active for long enough, since the interrupt
count never gets reset. Once it is throttled it never gets
unthrottled, so it basically just stops working at that point.
This fixes it by making perf_ctx_adjust_freq use ctx->event_list
rather than ctx->group_list. The existing spin_lock/spin_unlock
around the loop makes it unnecessary to put rcu_read_lock/
rcu_read_unlock around the list_for_each_entry_rcu().
Reported-by: Mark W. Krentel <krentel@cs.rice.edu>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <19157.26731.855609.165622@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
I was debuging some module using "function" and "function_graph"
tracers and noticed, that if you load module after you enabled
tracing, the module's hooks will convert only to NOP instructions.
The attached patch enables modules' hooks if there's function trace
allready on, thus allowing to trace module functions.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20091013203425.896285120@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The futex code does not handle spurious wake up in futex_wait and
futex_wait_requeue_pi.
The code assumes that any wake up which was not caused by futex_wake /
requeue or by a timeout was caused by a signal wake up and returns one
of the syscall restart error codes.
In case of a spurious wake up the signal delivery code which deals
with the restart error codes is not invoked and we return that error
code to user space. That causes applications which actually check the
return codes to fail. Blaise reported that on preempt-rt a python test
program run into a exception trap. -rt exposed that due to a built in
spurious wake up accelerator :)
Solve this by checking signal_pending(current) in the wake up path and
handle the spurious wake up case w/o returning to user space.
Reported-by: Blaise Gassend <blaise@willowgarage.com>
Debugged-by: Darren Hart <dvhltc@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@kernel.org
LKML-Reference: <new-submission>
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
cciss: Add cciss_allow_hpsa module parameter
cciss: Fix multiple calls to pci_release_regions
blk-settings: fix function parameter kernel-doc notation
writeback: kill space in debugfs item name
writeback: account IO throttling wait as iowait
elv_iosched_store(): fix strstrip() misuse
cfq-iosched: avoid probable slice overrun when idling
cfq-iosched: apply bool value where we return 0/1
cfq-iosched: fix think time allowed for seekers
cfq-iosched: fix the slice residual sign
cfq-iosched: abstract out the 'may this cfqq dispatch' logic
block: use proper BLK_RW_ASYNC in blk_queue_start_tag()
block: Seperate read and write statistics of in_flight requests v2
block: get rid of kblock_schedule_delayed_work()
cfq-iosched: fix possible problem with jiffies wraparound
cfq-iosched: fix issue with rq-rq merging and fifo list ordering
Remove the ftrace_trace_addr() function as only its off-case is
implemented and there are no users of it currently.
But we keep ftrace_graph_addr() off-case, in case someone come to use
the function graph tracer to profit from top-level callers filtering.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Do this rename because set_ftrace is too much generic and not enough
self-explainable as a name.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Every time we set a filter, we leak memory allocated by
postfix_append_operand() and postfix_append_op().
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
Cc: <stable@kernel.org> # for v2.6.31.x
LKML-Reference: <4AD3D7D9.4070400@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Rename probe-common fixed field names to harder conflictable names,
because current 'ip', 'func', and other probe field names are easily in
conflict with user-specified variable names.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
LKML-Reference: <20091007222814.1684.407.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Check whether the argument name is in conflict with other field names
while creating a kprobe through the debugfs interface.
Changes in v3:
- Check strcmp() == 0 instead of !strcmp().
Changes in v2:
- Add common_lock_depth to reserved name list.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
LKML-Reference: <20091007222807.1684.26880.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Rename special variables to more self-explainable names as below:
- $rv to $retval
- $sa to $stack
- $aN to $argN
- $sN to $stackN
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
LKML-Reference: <20091007222759.1684.3319.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Add a command line parameter to allow limiting the function graphs
that are traced on boot up from the given top-level callers , when
ftrace=function_graph is specified.
This patch adds the following command line option:
ftrace_graph_filter=function-list
Where function-list is a comma separated list of functions to filter.
[fweisbec@gmail.com: picked the documentation changes from the v2 patch]
Signed-off-by: Stefan Assmann <sassmann@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4AD2DEB9.2@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Remove '$ra' (return address) because it is already shown at the head of
each entry.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
LKML-Reference: <20091007222748.1684.12711.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Add $ prefix to the special variables(e.g. sa, rv) of kprobe-tracer.
This resolves consistency issues between kprobe_events and perf-kprobe.
The main goal is to avoid conflicts between local variable names of
probed functions, used by perf probe, and special variables used
in the kprobe event creation interface (stack values, etc...) and
also available from perf probe.
ie: we don't want rv (return value) to conflict with a local variable
named rv in a probed function.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Frank Ch. Eigler <fche@redhat.com>
LKML-Reference: <20091007222740.1684.91170.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
The following htmldocs warnings:
Warning(kernel/sched.c:685): No description found for parameter 'cpu'
Warning(kernel/sched.c:3676): No description found for parameter 'sd'
Trigger because new parameters were added to update_rq_clock() and
update_group_power() without updating the kernel-doc notation.
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <4AD29070.7070002@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
After m68k's task_thread_info() doesn't refer to current,
it's possible to remove sched.h from interrupt.h and not break m68k!
Many thanks to Heiko Carstens for allowing this.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
In try_to_wake_up(), we update the runqueue clock, but
select_task_rq() may select a different runqueue than the one we
updated, leaving the new runqueue's clock stale for a bit.
This patch cures occasional huge latencies reported by latencytop
when coming out of idle on a mostly idle NO_HZ box.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1255070103.7639.30.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some tracepoint magic (TRACE_EVENT(lock_acquired)) relies on
the fact that lock hold times are positive and uses div64 on
that. That triggered a build warning on MIPS, and probably
causes bad output in certain circumstances as well.
Make it truly positive.
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1254818502.21044.112.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It makes sense to do IOWAIT when someone is blocked
due to IO throttle, as suggested by Kame and Peter.
There is an old comment for not doing IOWAIT on throttle,
however it has been mismatching the code for a long time.
If we stop accounting IOWAIT for 2.6.32, it could be an
undesirable behavior change. So restore the io_schedule.
CC: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
The addition of trace_array_{v}printk used the wrong function for
trace_vprintk to call. This broke trace_marker and trace_vprintk
itself. Although trace_printk may not have been affected by those
that end up calling trace_vbprintk.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futex: fix requeue_pi key imbalance
futex: Fix typo in FUTEX_WAIT/WAKE_BITSET_PRIVATE definitions
rcu: Place root rcu_node structure in separate lockdep class
rcu: Make hot-unplugged CPU relinquish its own RCU callbacks
rcu: Move rcu_barrier() to rcutree
futex: Move exit_pi_state() call to release_mm()
futex: Nullify robust lists after cleanup
futex: Fix locking imbalance
panic: Fix panic message visibility by calling bust_spinlocks(0) before dying
rcu: Replace the rcu_barrier enum with pointer to call_rcu*() function
rcu: Clean up code based on review feedback from Josh Triplett, part 4
rcu: Clean up code based on review feedback from Josh Triplett, part 3
rcu: Fix rcu_lock_map build failure on CONFIG_PROVE_LOCKING=y
rcu: Clean up code to address Ingo's checkpatch feedback
rcu: Clean up code based on review feedback from Josh Triplett, part 2
rcu: Clean up code based on review feedback from Josh Triplett
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Set correct normal_prio and prio values in sched_fork()
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing: user local buffer variable for trace branch tracer
tracing: fix warning on kernel/trace/trace_branch.c andtrace_hw_branches.c
ftrace: check for failure for all conversions
tracing: correct module boundaries for ftrace_release
tracing: fix transposed numbers of lock_depth and preempt_count
trace: Fix missing assignment in trace_ctxwake_*
tracing: Use free_percpu instead of kfree
tracing: Check total refcount before releasing bufs in profile_enable failure
* 'sparc-perf-events-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
mm, perf_event: Make vmalloc_user() align base kernel virtual address to SHMLBA
perf_event: Provide vmalloc() based mmap() backing
* 'perf-fixes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf_events: Make ABI definitions available to userspace
perf tools: elf_sym__is_function() should accept "zero" sized functions
tracing/syscalls: Use long for syscall ret format and field definitions
perf trace: Update eval_flag() flags array to match interrupt.h
perf trace: Remove unused code in builtin-trace.c
perf: Propagate term signal to child
Just using the tr->buffer for the API to trace_buffer_lock_reserve
is not good enough. This is because the tr->buffer may change, and we
do not want to commit with a different buffer that we reserved from.
This patch uses a local variable to hold the buffer that was used to
reserve and commit with.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
fix warnings that caused the API change of trace_buffer_lock_reserve()
change files: kernel/trace/trace_hw_branch.c
kernel/trace/trace_branch.c
Signed-off-by: Zhenwen Xu <helight.xu@gmail.com>
LKML-Reference: <20091008012146.GA4170@helight>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Due to legacy code from back when the dynamic tracer used a daemon,
only core kernel code was checking for failures. This is no longer
the case. We must check for failures any time we perform text modifications.
Cc: stable@kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
When the module is about the unload we release its call records.
The ftrace_release function was given wrong values representing
the module core boundaries, thus not releasing its call records.
Plus making ftrace_release function module specific.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
LKML-Reference: <1254934835-363-3-git-send-email-jolsa@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If futex_wait_requeue_pi() wakes prior to requeue, we drop the
reference to the source futex_key twice, once in
handle_early_requeue_pi_wakeup() and once on our way out.
Remove the drop from the handle_early_requeue_pi_wakeup() and keep
the get/drops together in futex_wait_requeue_pi().
Reported-by: Helge Bahmann <hcb@chaoticmind.net>
Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Cc: Helge Bahmann <hcb@chaoticmind.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dinakar Guniguntala <dino@in.ibm.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: stable-2.6.31 <stable@kernel.org>
LKML-Reference: <4ACCE21E.5030805@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Commit f2e21c9610 had unfortunate side
effects with cpufreq governors on some systems.
If the system did not switch into NOHZ mode ts->inidle is not set when
tick_nohz_stop_sched_tick() is called from the idle routine. Therefor
all subsequent calls from irq_exit() to tick_nohz_stop_sched_tick()
fail to call tick_nohz_start_idle(). This results in bogus idle
accounting information which is passed to cpufreq governors.
Set the inidle flag unconditionally of the NOHZ active state to keep
the idle time accounting correct in any case.
[ tglx: Added comment and tweaked the changelog ]
Reported-by: Steven Noonan <steven@uplinklabs.net>
Signed-off-by: Eero Nurkkala <ext-eero.nurkkala@nokia.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Greg KH <greg@kroah.com>
Cc: Steven Noonan <steven@uplinklabs.net>
Cc: stable@kernel.org
LKML-Reference: <1254907901.30157.93.camel@eenurkka-desktop>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Before this patch, all of the rcu_node structures were in the same lockdep
class, so that lockdep would complain when rcu_preempt_offline_tasks()
acquired the root rcu_node structure's lock while holding one of the leaf
rcu_nodes' locks.
This patch changes rcu_init_one() to use a separate
spin_lock_init() for the root rcu_node structure's lock than is
used for that of all of the rest of the rcu_node structures, which
puts the root rcu_node structure's lock in its own lockdep class.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <12548908983277-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The current interaction between RCU and CPU hotplug requires that
RCU block in CPU notifiers waiting for callbacks to drain.
This can be greatly simplified by having each CPU relinquish its
own callbacks, and for both _rcu_barrier() and CPU_DEAD notifiers
to adopt all callbacks that were previously relinquished.
This change also eliminates the possibility of certain types of
hangs due to the previous practice of waiting for callbacks to be
invoked from within CPU notifiers. If you don't every wait, you
cannot hang.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1254890898456-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
exit_pi_state() is called from do_exit() but not from do_execve().
Move it to release_mm() so it gets called from do_execve() as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Cc: stable@kernel.org
Cc: Anirban Sinha <ani@anirban.org>
Cc: Peter Zijlstra <peterz@infradead.org>
