Fix an obscure ABI feature that is a bit of a hassle to implement.
However, somebody put it into the ABI, so let's fill in a sensible
value there.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Add information regarding the 2.6.32 update to the xmit variant of
fw_cdev_event_iso_interrupt.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The problem:
A target-like userspace driver, e.g. AV/C target or SBP-2/3 target,
needs to be able to act as responder and requester. In the latter role,
it needs to send requests to nods from which it received requests. This
is currently impossible because fw_cdev_event_request lacks information
about sender node ID.
Reported-by: Jay Fenlason <fenlason@redhat.com>
Libffado + libraw1394 + firewire-core is currently unable to drive two
or more audio devices on the same bus.
Reported-by: Arnold Krille <arnold@arnoldarts.de>
This is because libffado requires destination node ID of FCP requests
and sender node ID of FCP responses to match. It even prohibits
libffado from working with a bus on which libraw1394 opens a /dev/fw* as
default ioctl device that does not correspond with the audio device.
This is because libraw1394 does not receive the sender node ID from the
kernel.
Moreover, fw_cdev_event_request makes it impossible to tell unicast and
broadcast write requests apart.
The fix:
Add a replacement of struct fw_cdev_event_request request, boringly
called struct fw_cdev_event_request2. The new event will be sent to a
userspace client instead of the old one if the client claims
compatibility with <linux/firewire-cdev.h> ABI version 4 or later.
libraw1394 needs to be extended to make use of the new event, in order
to properly support libffado and other FCP or address range mapping
users who require correct sender node IDs.
Further notes:
While we are at it, change back the range of possible values of
fw_cdev_event_request.tcode to 0x0...0xb like in ABI version <= 3.
The preceding change "firewire: expose extended tcode of incoming lock
requests to (userspace) drivers" expanded it to 0x0...0x17 which could
catch sloppily coded clients by surprise. The extended range of codes
is only used in the new fw_cdev_event_request2.tcode.
Jay and I also suggested an alternative approach to fix the ABI for
incoming requests: Add an FW_CDEV_IOC_GET_REQUEST_INFO ioctl which can
be called after reception of an fw_cdev_event_request, before issuing of
the closing FW_CDEV_IOC_SEND_RESPONSE ioctl. The new ioctl would reveal
the vital information about a request that fw_cdev_event_request lacks.
Jay showed an implementation of this approach.
The former event approach adds 27 LOC of rather trivial code to
core-cdev.c, the ioctl approach 34 LOC, some of which is nontrivial.
The ioctl approach would certainly also add more LOC to userspace
programs which require the expanded information on inbound requests.
This approach is probably only on the lighter-weight side in case of
clients that want to be compatible with kernels that lack the new
capability, like libraw1394. However, the code to be added to such
libraw1394-like clients in case of the event approach is a straight-
forward additional switch () case in its event handler.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
libraw1394 v2.0.0...v2.0.5 takes FW_CDEV_VERSION from an externally
installed header file and uses it to declare its own implementation
level in FW_CDEV_IOC_GET_INFO. This is wrong; it should set the real
version for which it was actually written.
If we add features to the kernel ABI that require the kernel to check
a client's implementation level, we can not trust the client version if
it was set from FW_CDEV_VERSION.
Hence freeze FW_CDEV_VERSION at the current value (no damage has been
done yet), clearly document FW_CDEV_VERSION as a dummy version and what
clients are expected to do with fw_cdev_get_info.version, and use a new
defined constant (which is not placed into the exported header file) as
kernel implementation level.
Note, in order to check in client program source code which features are
present in an externally installed linux/firewire-cdev.h, use
preprocessor directives like
#ifdef FW_CDEV_IOC_ALLOCATE_ISO_RESOURCE
or
#ifdef FW_CDEV_EVENT_ISO_RESOURCE_ALLOCATED
instead of a check of FW_CDEV_VERSION.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
void (*fw_address_callback_t)(..., int speed, ...) is the speed that a
remote node chose to transmit a request to us. In case of split
transactions, firewire-core will transmit the response at that speed.
Upper layer drivers on the other hand (firewire-net, -sbp2, firedtv, and
userspace drivers) cannot do anything useful with that speed datum,
except log it for debug purposes. But data that is merely potentially
(not even actually) used for debug purposes does not belong into the API.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Push the maintenance of STATE_CLEAR/SET.abdicate down into the card
driver. This way, the read/write_csr_reg driver method works uniformly
across all CSR offsets.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
by feature variables in the fw_card struct. The hook appeared to be an
unnecessary abstraction in the card driver interface.
Cleaner would be to pass those feature flags as arguments to
fw_card_initialize() or fw_card_add(), but the FairnessControl register
is in the SCLK domain and may therefore not be accessible while Link
Power Status is off, i.e. before the card->driver->enable call from
fw_card_add().
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Implement the abdicate bit, which is required for bus manager
capable nodes and tested by the Base 1394 Test Suite.
Finally, something to do at a command reset! :-)
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Implement the MAIN_UTILITY register, which is utterly optional
but useful as a safe target for diagnostic read/write/broadcast
transactions.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
If supported by the OHCI controller, implement the PRIORITY_BUDGET
register, which is required for nodes that can use asynchronous
priority arbitration.
To allow the core to determine what features the lowlevel device
supports, add a new card driver callback.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Implement the SPLIT_TIMEOUT registers. Besides being required by the
spec, this is desirable for some IIDC devices and necessary for many
audio devices to be able to increase the timeout from userspace.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Using a single timeout for all transaction that need to be flushed does
not work if the submission of new transactions can defer the timeout
indefinitely into the future. We need to have timeouts that do not
change due to other transactions; the simplest way to do this is with a
separate timer for each transaction.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (+ one lockdep annotation)
Clemens Ladisch pointed out that
- BIB_IMC is not named like the field is called in the standard,
- readers of the code may get worried about the magic 0x0c0083c0,
- a CSR_NODE_CAPABILITIES key is there in the header but not put to
good use.
So let's rename BIB_IMC, add a defined constant for Node_Capabilities
and a comment which reassures people that somebody thought about it and
they don't have to (or if they still do, tell them where they have to
look for confirmation), and prune our incomplete and arbitrary set of
defined constants of CSR key IDs. And there is a nother magic number,
that of Bus_Information_Block.Bus_Name, to be defined and commented.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Add the missing documentation for iso packets.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This code was no longer used since 2.6.33, "firewire: ohci: always use
packet-per-buffer mode for isochronous reception" commit 090699c0. If
anybody needs this code in the future for special purposes, it can be
brought back in. But it must not be re-enabled by default; drivers
(kernelspace or userspace drivers) should only get this mode if they
explicitly request it.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
so that clients can detect whether the FW_CDEV_IOC_GET_CYCLE_TIMER ioctl
is reliable (on all tested controllers, especially the widely used VIA
controllers, also NEC controllers, see commits b677532b and 1c1517ef).
Also add a comment on the 2.6.32 iso xmit enhancement and on dual-buffer
IR having been disabled in 2.6.33.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The system time from CLOCK_REALTIME is not monotonic, hence problematic
for the main user of the FW_CDEV_IOC_GET_CYCLE_TIMER ioctl. This issue
exists in its successor ABI, i.e. raw1394, too.
http://subversion.ffado.org/ticket/242
We now offer an alternative ioctl which lets the caller choose between
CLOCK_REALTIME, CLOCK_MONOTONIC, and CLOCK_MONOTONIC_RAW as source of
the local time, very similar to the clock_gettime libc function. The
format of the local time return value matches that of clock_gettime
(seconds and nanoseconds, instead of a single microseconds value from
the existing ioctl).
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This reverts commit fb1e75389b.
"Benjamin S." <sbenni@gmx.de> reports that the patch in question
causes a big drop in sequential throughput for him, dropping from
200MB/sec down to only 70MB/sec.
Needs to be investigated more fully, for now lets just revert the
offending commit.
Conflicts:
include/linux/blkdev.h
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
CacheFiles: Fix a race in cachefiles_delete_object() vs rename
vfs: don't call ima_file_check() unconditionally in nfsd_open()
fs: inode - remove 8 bytes of padding on 64bits allowing 1 more objects/slab under slub
Switch proc/self to nd_set_link()
fix LOOKUP_FOLLOW on automount "symlinks"
This fixes the filepath encoded in <linux/amba/bus.h> and adds
some documentation as to what this bus really means.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This removes 8 bytes of padding from struct inode on 64bit builds, and
so allows 1 more object/slab in the inode_cache when using slub.
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
----
patch against 2.6.33-rc8
compiled & tested on x86_64 AMDX2
I've been running this patch for over a week with no obvious problems
regards
Richard
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Most laptops have keys that are intended to toggle all device state, not
just wifi. These are currently generally mapped to KEY_WLAN. As a result,
rfkill will only kill or enable wifi in response to the key press. This
confuses users and can make it difficult for them to enable bluetooth
and wwan devices.
This patch adds a new keycode, KEY_RFKILL. It indicates that the system
should toggle the state of all rfkillable devices.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This patch fixes following sparse warnings:
include/linux/kfifo.h:127:25: warning: Using plain integer as NULL pointer
kernel/kfifo.c:83:21: warning: Using plain integer as NULL pointer
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf top: Fix help text alignment
perf: Fix hypervisor sample reporting
perf: Make bp_len type to u64 generic across the arch
* 'nouveau/for-airlied' of /home/airlied/kernel/drm-next:
nouveau: fix state detection with switchable graphics
drm/nouveau: move dereferences after null checks
drm/nv50: make the pgraph irq handler loop like the pre-nv50 version
drm/nv50: delete ramfc object after disabling fifo, not before
drm/nv50: avoid unloading pgraph context when ctxprog is running
drm/nv50: align size of buffer object to the right boundaries.
drm/nv50: disregard dac outputs in nv50_sor_dpms()
drm/nv50: prevent multiple init tables being parsed at the same time
drm/nouveau: make dp auxch xfer len check for reads only
drm/nv40: make INIT_COMPUTE_MEM a NOP, just like nv50
drm/nouveau: Add proper vgaarb support.
drm/nouveau: Fix fbcon on mixed pre-NV50 + NV50 multicard.
drivers/gpu/drm/nouveau/nouveau_grctx.c: correct NULL test
drm/nouveau: call ttm_bo_wait with the bo lock held to prevent hang
drm/nouveau: Fixup semaphores on pre-nv50 cards.
drm/nouveau: Add getparam to get available PGRAPH units.
drm/nouveau: Add module options to disable acceleration.
drm/nouveau: fix non-vram notifier blocks
Even if this bumps the version to 1 it does not mean the driver is
out of staging. From what we know this is the last backwards
incompatible change to the driver.
Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
When time-based throttling is implemented, we need to bump minor.
When the old way of detecting scanout is removed, we need to bump major.
In the meantime, this change should not break existing user-space.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
On nv50, this will be needed by applications using CUDA to know
how much stack/local memory to allocate.
Signed-off-by: Marcin Kościelnicki <koriakin@0x04.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
As noticed by Jon Masters <jonathan@jonmasters.org>, the conntrack hash
size is global and not per namespace, but modifiable at runtime through
/sys/module/nf_conntrack/hashsize. Changing the hash size will only
resize the hash in the current namespace however, so other namespaces
will use an invalid hash size. This can cause crashes when enlarging
the hashsize, or false negative lookups when shrinking it.
Move the hash size into the per-namespace data and only use the global
hash size to initialize the per-namespace value when instanciating a
new namespace. Additionally restrict hash resizing to init_net for
now as other namespaces are not handled currently.
Cc: stable@kernel.org
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
nf_conntrack_cachep is currently shared by all netns instances, but
because of SLAB_DESTROY_BY_RCU special semantics, this is wrong.
If we use a shared slab cache, one object can instantly flight between
one hash table (netns ONE) to another one (netns TWO), and concurrent
reader (doing a lookup in netns ONE, 'finding' an object of netns TWO)
can be fooled without notice, because no RCU grace period has to be
observed between object freeing and its reuse.
We dont have this problem with UDP/TCP slab caches because TCP/UDP
hashtables are global to the machine (and each object has a pointer to
its netns).
If we use per netns conntrack hash tables, we also *must* use per netns
conntrack slab caches, to guarantee an object can not escape from one
namespace to another one.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
[Patrick: added unique slab name allocation]
Cc: stable@kernel.org
Signed-off-by: Patrick McHardy <kaber@trash.net>
ima_path_check actually deals with files! call it ima_file_check instead.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The "Untangling ima mess, part 2 with counters" patch messed
up the counters. Based on conversations with Al Viro, this patch
streamlines ima_path_check() by removing the counter maintaince.
The counters are now updated independently, from measuring the file,
in __dentry_open() and alloc_file() by calling ima_counts_get().
ima_path_check() is called from nfsd and do_filp_open().
It also did not measure all files that should have been measured.
Reason: ima_path_check() got bogus value passed as mask.
[AV: mea culpa]
[AV: add missing nfsd bits]
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
[libata] Call flush_dcache_page after PIO data transfers in libata-sff.c
ahci: add Acer G725 to broken suspend list
libata: fix ata_id_logical_per_physical_sectors
libata-scsi passthru: fix bug which truncated LBA48 return values
This is to make the annotation of percpu variables during the next merge
window less painfull.
Extracted from a patch by Rusty Russell.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futex: Handle futex value corruption gracefully
futex: Handle user space corruption gracefully
futex_lock_pi() key refcnt fix
softlockup: Add sched_clock_tick() to avoid kernel warning on kgdb resume
The value we get from the low byte of the ATA_ID_SECTOR_SIZE word is not not
a plain multiple, but the log of it, so fix the helper to give the correct
answer. Without this we'll get an incorrect minimal I/O size in the block
limits VPD page for 4k sector drives.
Also change the return value of ata_id_logical_per_physical_sectors to u16
for the unlikely case of very large logical sectors.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Change 'bp_len' type to __u64 to make it work across archs as
the s390 architecture watch point length can be upto 2^64.
reference:
http://lkml.org/lkml/2010/1/25/212
This is an ABI change that is not backward compatible with
the previous hardware breakpoint info layout integrated in this
development cycle, a rebuilt of perf tools is necessary for
versions based on 2.6.33-rc1 - 2.6.33-rc6 to work with a
kernel based on this patch.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin <schwidefsky@de.ibm.com>
LKML-Reference: <20100130045518.GA20776@in.ibm.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (23 commits)
connector: Delete buggy notification code.
be2net: use eq-id to calculate cev-isr reg offset
Bluetooth: Use the control channel for raw HID reports
Bluetooth: Add DFU driver for Atheros Bluetooth chipset AR3011
Bluetooth: Redo checks in IRQ handler for shared IRQ support
Bluetooth: Fix memory leak in L2CAP
Bluetooth: Remove double free of SKB pointer in L2CAP
cdc_ether: Partially revert "usbnet: Set link down initially ..."
be2net: Fix memset() arg ordering.
bonding: bond_open error return value
ixgbe: if ixgbe_copy_dcb_cfg is going to fail learn about it early
ixgbe: set the correct DCB bit for pg tx settings
igbvf: fix issue w/ mapped_as_page being left set after unmap
drivers/net: ks8851_mll ethernet network driver
be2net: Bug fix to support newer generation of BE ASIC
starfire: clean up properly if firmware loading fails
mac80211: fix NULL pointer dereference when ftrace is enabled
netfilter: ctnetlink: fix expectation mask dump
ipv6: conntrack: Add member of user to nf_ct_frag6_queue structure
ath9k: fix eeprom INI values override for 2GHz-only cards
...
On Tue, Feb 02, 2010 at 02:57:14PM -0800, Greg KH (gregkh@suse.de) wrote:
> > There are at least two ways to fix it: using a big cannon and a small
> > one. The former way is to disable notification registration, since it is
> > not used by anyone at all. Second way is to check whether calling
> > process is root and its destination group is -1 (kind of priveledged
> > one) before command is dispatched to workqueue.
>
> Well if no one is using it, removing it makes the most sense, right?
>
> No objection from me, care to make up a patch either way for this?
Getting it is not used, let's drop support for notifications about
(un)registered events from connector.
Another option was to check credentials on receiving, but we can always
restore it without bugs if needed, but genetlink has a wider code base
and none complained, that userspace can not get notification when some
other clients were (un)registered.
Kudos for Sebastian Krahmer <krahmer@suse.de>, who found a bug in the
code.
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
drm/radeon/kms: Fix oops after radeon_cs_parser_init() failure.
drm/radeon/kms: move radeon KMS on/off switch out of staging.
drm/radeon/kms: Bailout of blit if error happen & protect with mutex V3
drm/vmwgfx: Don't send bad flags to the host
drm/vmwgfx: Request SVGA version 2 and bail if not found
drm/vmwgfx: Correctly detect 3D
drm/ttm: remove unnecessary save_flags and ttm_flag_masked in ttm_bo_util.c
drm/kms: Remove incorrect comment in struct drm_mode_modeinfo
drm/ttm: remove padding from ttm_ref_object on 64bit builds
drm/radeon/kms: release agp on error.
drm/kms/radeon/agp: Move the check of the aper_size after drm_acp_acquire and drm_agp_info
drm/kms/radeon/agp: Fix warning, format ‘%d’ expects type ‘int’, but argument 4 has type ‘size_t’
drm/ttm: Avoid conflicting reserve_memtype during ttm_tt_set_page_caching.
drm/kms/radeon: pick digitial encoders smarter. (v3)
drm/radeon/kms: use active device to pick connector for encoder
drm/radeon/kms: fix incorrect logic in DP vs eDP connector checking.
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf, hw_breakpoint, kgdb: Do not take mutex for kernel debugger
x86, hw_breakpoints, kgdb: Fix kgdb to use hw_breakpoint API
hw_breakpoints: Release the bp slot if arch_validate_hwbkpt_settings() fails.
perf: Ignore perf.data.old
perf report: Fix segmentation fault when running with '-g none'
When CONFIG_HAVE_UNSTABLE_SCHED_CLOCK is set, sched_clock() gets
the time from hardware such as the TSC on x86. In this
configuration kgdb will report a softlock warning message on
resuming or detaching from a debug session.
Sequence of events in the problem case:
1) "cpu sched clock" and "hardware time" are at 100 sec prior
to a call to kgdb_handle_exception()
2) Debugger waits in kgdb_handle_exception() for 80 sec and on
exit the following is called ... touch_softlockup_watchdog() -->
__raw_get_cpu_var(touch_timestamp) = 0;
3) "cpu sched clock" = 100s (it was not updated, because the
interrupt was disabled in kgdb) but the "hardware time" = 180 sec
4) The first timer interrupt after resuming from
kgdb_handle_exception updates the watchdog from the "cpu sched clock"
update_process_times() { ... run_local_timers() -->
softlockup_tick() --> check (touch_timestamp == 0) (it is "YES"
here, we have set "touch_timestamp = 0" at kgdb) -->
__touch_softlockup_watchdog() ***(A)--> reset "touch_timestamp"
to "get_timestamp()" (Here, the "touch_timestamp" will still be
set to 100s.) ...
scheduler_tick() ***(B)--> sched_clock_tick() (update "cpu sched
clock" to "hardware time" = 180s) ... }
5) The Second timer interrupt handler appears to have a large
jump and trips the softlockup warning.
update_process_times() { ... run_local_timers() -->
softlockup_tick() --> "cpu sched clock" - "touch_timestamp" =
180s-100s > 60s --> printk "soft lockup error messages" ... }
note: ***(A) reset "touch_timestamp" to
"get_timestamp(this_cpu)"
Why is "touch_timestamp" 100 sec, instead of 180 sec?
When CONFIG_HAVE_UNSTABLE_SCHED_CLOCK is set, the call trace of
get_timestamp() is:
get_timestamp(this_cpu)
-->cpu_clock(this_cpu)
-->sched_clock_cpu(this_cpu)
-->__update_sched_clock(sched_clock_data, now)
The __update_sched_clock() function uses the GTOD tick value to
create a window to normalize the "now" values. So if "now"
value is too big for sched_clock_data, it will be ignored.
The fix is to invoke sched_clock_tick() to update "cpu sched
clock" in order to recover from this state. This is done by
introducing the function touch_softlockup_watchdog_sync(). This
allows kgdb to request that the sched clock is updated when the
watchdog thread runs the first time after a resume from kgdb.
[yong.zhang0@gmail.com: Use per cpu instead of an array]
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Dongdong Deng <Dongdong.Deng@windriver.com>
Cc: kgdb-bugreport@lists.sourceforge.net
Cc: peterz@infradead.org
LKML-Reference: <1264631124-4837-2-git-send-email-jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch fixes the regression in functionality where the
kernel debugger and the perf API do not nicely share hw
breakpoint reservations.
The kernel debugger cannot use any mutex_lock() calls because it
can start the kernel running from an invalid context.
A mutex free version of the reservation API needed to get
created for the kernel debugger to safely update hw breakpoint
reservations.
The possibility for a breakpoint reservation to be concurrently
processed at the time that kgdb interrupts the system is
improbable. Should this corner case occur the end user is
warned, and the kernel debugger will prohibit updating the
hardware breakpoint reservations.
Any time the kernel debugger reserves a hardware breakpoint it
will be a system wide reservation.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: kgdb-bugreport@lists.sourceforge.net
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: torvalds@linux-foundation.org
LKML-Reference: <1264719883-7285-3-git-send-email-jason.wessel@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
