20 Mar, 2014
1 commit
-
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).Instead, the correct and race-free way of performing the callback
registration is:cpu_notifier_register_begin();
for_each_online_cpu(cpu)
init_cpu(cpu);/* Note the use of the double underscored version of the API */
__register_cpu_notifier(&foobar_cpu_notifier);cpu_notifier_register_done();
Fix the nmi-timer code in oprofile by using this latter form of callback
registration.Cc: Robert Richter
Cc: Ingo Molnar
Signed-off-by: Srivatsa S. Bhat
Signed-off-by: Rafael J. Wysocki
04 Sep, 2013
6 commits
-
Signed-off-by: Al Viro
-
same story as with oprofilefs_mkdir()
Signed-off-by: Al Viro
-
it's always equal to ->d_sb of the second argument (parent dentry),
due to either being literally that, or ->d_sb of parent's parent.Signed-off-by: Al Viro
-
Signed-off-by: Al Viro
-
Signed-off-by: Al Viro
-
it's always root->d_sb
Signed-off-by: Al Viro
15 Jul, 2013
1 commit
-
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.This removes all the remaining one-off uses of the __cpuinit macros
from all C files in the drivers/* directory.[1] https://lkml.org/lkml/2013/5/20/589
Cc: Greg Kroah-Hartman
Acked-by: Greg Kroah-Hartman
Signed-off-by: Paul Gortmaker
04 Mar, 2013
1 commit
-
Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives. Allowing simple, safe,
well understood work-arounds to known problematic software.This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work. While writing this patch I saw a handful of such
cases. The most significant being autofs that lives in the module
autofs4.This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module. The common pattern in the kernel is to call request_module()
without regards to the users permissions. In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted. In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.Acked-by: Serge Hallyn
Acked-by: Kees Cook
Reported-by: Kees Cook
Signed-off-by: "Eric W. Biederman"
23 Feb, 2013
1 commit
-
Right now it's safe only during initial mount *and* functions are asking
to be abused for dynamic adding of objects.Signed-off-by: Al Viro
09 Oct, 2012
1 commit
-
Some security modules and oprofile still uses VM_EXECUTABLE for retrieving
a task's executable file. After this patch they will use mm->exe_file
directly. mm->exe_file is protected with mm->mmap_sem, so locking stays
the same.Signed-off-by: Konstantin Khlebnikov
Acked-by: Chris Metcalf [arch/tile]
Acked-by: Tetsuo Handa [tomoyo]
Cc: Alexander Viro
Cc: Carsten Otte
Cc: Cyrill Gorcunov
Cc: Eric Paris
Cc: H. Peter Anvin
Cc: Hugh Dickins
Cc: Ingo Molnar
Acked-by: James Morris
Cc: Jason Baron
Cc: Kentaro Takeda
Cc: Matt Helsley
Cc: Nick Piggin
Cc: Oleg Nesterov
Cc: Peter Zijlstra
Cc: Robert Richter
Cc: Suresh Siddha
Cc: Venkatesh Pallipadi
Acked-by: Linus Torvalds
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Aug, 2012
1 commit
-
Under certain workloads we see the following warnings:
WQ on CPU0, prefer CPU1
WQ on CPU0, prefer CPU2
WQ on CPU0, prefer CPU3It warns the user that the wq to access a per-cpu buffers runs not on
the same cpu. This happens if the wq is rescheduled on a different cpu
than where the buffer is located. This was probably implemented to
detect performance issues. Not sure if there actually is one as the
buffers are copied to a single buffer anyway which should be the
actual bottleneck.We wont change WQ implementation. Since a user can do nothing the
warning is pointless. Removing it.Cc: Andi Kleen
Signed-off-by: Robert Richter
22 Jun, 2012
1 commit
-
This changes oprofile_perf.c to use the per-cpu framework.
Using the per-cpu framework should avoid error like the following:
arch/arm/oprofile/../../../drivers/oprofile/oprofile_perf.c:28:28: error: variably modified 'perf_events' at file scope
Reported-by: William Cohen
Cc: Will Deacon
Signed-off-by: Robert Richter
21 Jun, 2012
1 commit
-
The OProfile perf backend uses a static array to keep track of the
perf events on the system. When compiling with CONFIG_CPUMASK_OFFSTACK=y
&& SMP, nr_cpumask_bits is not a compile-time constant and the build
will fail with:oprofile_perf.c:28: error: variably modified 'perf_events' at file scope
This patch uses NR_CPUs instead of nr_cpumask_bits for the array
initialisation. If this causes space problems in the future, we can
always move to dynamic allocation for the events array.Cc: Matt Fleming
Reported-by: Russell King - ARM Linux
Signed-off-by: Will Deacon
Cc: # v2.6.37+
Signed-off-by: Robert Richter
06 Apr, 2012
1 commit
-
Many users of debugfs copy the implementation of default_open() when
they want to support a custom read/write function op. This leads to a
proliferation of the default_open() implementation across the entire
tree.Now that the common implementation has been consolidated into libfs we
can replace all the users of this function with simple_open().This replacement was done with the following semantic patch:
@ open @
identifier open_f != simple_open;
identifier i, f;
@@
-int open_f(struct inode *i, struct file *f)
-{
(
-if (i->i_private)
-f->private_data = i->i_private;
|
-f->private_data = i->i_private;
)
-return 0;
-}@ has_open depends on open @
identifier fops;
identifier open.open_f;
@@
struct file_operations fops = {
...
-.open = open_f,
+.open = simple_open,
...
};[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Stephen Boyd
Cc: Greg Kroah-Hartman
Cc: Al Viro
Cc: Julia Lawall
Acked-by: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Mar, 2012
2 commits
-
Signed-off-by: Al Viro
-
Signed-off-by: Al Viro
07 Jan, 2012
1 commit
-
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (106 commits)
perf kvm: Fix copy & paste error in description
perf script: Kill script_spec__delete
perf top: Fix a memory leak
perf stat: Introduce get_ratio_color() helper
perf session: Remove impossible condition check
perf tools: Fix feature-bits rework fallout, remove unused variable
perf script: Add generic perl handler to process events
perf tools: Use for_each_set_bit() to iterate over feature flags
perf tools: Unify handling of features when writing feature section
perf report: Accept fifos as input file
perf tools: Moving code in some files
perf tools: Fix out-of-bound access to struct perf_session
perf tools: Continue processing header on unknown features
perf tools: Improve macros for struct feature_ops
perf: builtin-record: Document and check that mmap_pages must be a power of two.
perf: builtin-record: Provide advice if mmap'ing fails with EPERM.
perf tools: Fix truncated annotation
perf script: look up thread using tid instead of pid
perf tools: Look up thread names for system wide profiling
perf tools: Fix comm for processes with named threads
...
20 Dec, 2011
2 commits
-
If oprofilefs_ulong_from_user() is called with count equals
zero, *val remains unchanged. Depending on the implementation it
might be uninitialized.Change oprofilefs_ulong_from_user()'s interface to return count
on success. Thus, we are able to return early if count equals
zero which avoids using *val uninitialized. Fixing all users of
oprofilefs_ulong_ from_user().This follows write syscall implementation when count is zero:
"If count is zero ... [and if] no errors are detected, 0 will be
returned without causing any other effect." (man 2 write)Reported-By: Mike Waychison
Signed-off-by: Robert Richter
Cc: Andrew Morton
Cc:
Cc: oprofile-list
Link: http://lkml.kernel.org/r/20111219153830.GH16765@erda.amd.com
Signed-off-by: Ingo Molnar
07 Dec, 2011
1 commit
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Removing remainings of oprofile_timer_exit() completly.
Signed-off-by: Robert Richter
15 Nov, 2011
2 commits
04 Nov, 2011
3 commits
-
The legacy x86 nmi watchdog code was removed with the implementation
of the perf based nmi watchdog. This broke Oprofile's nmi timer
mode. To run nmi timer mode we relied on a continuous ticking nmi
source which the nmi watchdog provided. The nmi tick was no longer
available and current watchdog can not be used anymore since it runs
with very long periods in the range of seconds. This patch
reimplements the nmi timer mode using a perf counter nmi source.V2:
* removing pr_info()
* fix undefined reference to `__udivdi3' for 32 bit build
* fix section mismatch of .cpuinit.data:nmi_timer_cpu_nb
* removed nmi timer setup in arch/x86
* implemented function stubs for op_nmi_init/exit()
* made code more readable in oprofile_init()V3:
* fix architectural initialization in oprofile_init()
* fix CONFIG_OPROFILE_NMI_TIMER dependenciesAcked-by: Peter Zijlstra
Signed-off-by: Robert Richter -
Remove exit functions by moving init/exit code to oprofile's setup/
shutdown functions. Doing so the oprofile module exit code will be
easier and less error-prone.Signed-off-by: Robert Richter
-
Oprofile may crash in a KVM guest while unlaoding modules. This
happens if oprofile_arch_init() fails and oprofile switches to the hr
timer mode as a fallback. In this case oprofile_arch_exit() is called,
but it never was initialized properly which causes the crash. This
patch fixes this.oprofile: using timer interrupt.
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: [] unregister_syscore_ops+0x41/0x58
PGD 41da3f067 PUD 41d80e067 PMD 0
Oops: 0002 [#1] PREEMPT SMP
CPU 5
Modules linked in: oprofile(-)Pid: 2382, comm: modprobe Not tainted 3.1.0-rc7-00018-g709a39d #18 Advanced Micro Device Anaheim/Anaheim
RIP: 0010:[] [] unregister_syscore_ops+0x41/0x58
RSP: 0018:ffff88041de1de98 EFLAGS: 00010296
RAX: 0000000000000000 RBX: ffffffffa00060e0 RCX: dead000000200200
RDX: 0000000000000000 RSI: dead000000100100 RDI: ffffffff8178c620
RBP: ffff88041de1dea8 R08: 0000000000000001 R09: 0000000000000082
R10: 0000000000000000 R11: ffff88041de1dde8 R12: 0000000000000080
R13: fffffffffffffff5 R14: 0000000000000001 R15: 0000000000610210
FS: 00007f9ae5bef700(0000) GS:ffff88042fd40000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000008 CR3: 000000041ca44000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process modprobe (pid: 2382, threadinfo ffff88041de1c000, task ffff88042db6d040)
Stack:
ffff88041de1deb8 ffffffffa0006770 ffff88041de1deb8 ffffffffa000251e
ffff88041de1dec8 ffffffffa00022c2 ffff88041de1ded8 ffffffffa0004993
ffff88041de1df78 ffffffff81073115 656c69666f72706f 0000000000610200
Call Trace:
[] op_nmi_exit+0x15/0x17 [oprofile]
[] oprofile_arch_exit+0xe/0x10 [oprofile]
[] oprofile_exit+0x13/0x15 [oprofile]
[] sys_delete_module+0x1c3/0x22f
[] ? trace_hardirqs_on_thunk+0x3a/0x3f
[] system_call_fastpath+0x16/0x1b
Code: 20 c6 78 81 e8 c5 cc 23 00 48 8b 13 48 8b 43 08 48 be 00 01 10 00 00 00 ad de 48 b9 00 02 20 00 00 00 ad de 48 c7 c7 20 c6 78 81
89 42 08 48 89 10 48 89 33 48 89 4b 08 e8 a6 c0 23 00 5a 5b
RIP [] unregister_syscore_ops+0x41/0x58
RSP
CR2: 0000000000000008
---[ end trace 06d4e95b6aa3b437 ]---CC: stable@kernel.org # 2.6.37+
Signed-off-by: Robert Richter
13 Sep, 2011
1 commit
-
The oprofilefs_lock can be taken in atomic context (in profiling
interrupts) and therefore cannot cannot be preempted on -rt -
annotate it.In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.Signed-off-by: Thomas Gleixner
Signed-off-by: Ingo Molnar
27 Jul, 2011
1 commit
-
This allows us to move duplicated code in
(atomic_inc_not_zero() for now) toSigned-off-by: Arun Sharma
Reviewed-by: Eric Dumazet
Cc: Ingo Molnar
Cc: David Miller
Cc: Eric Dumazet
Acked-by: Mike Frysinger
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Jul, 2011
1 commit
-
In commit a8b0ca17b80e ("perf: Remove the nmi parameter from the
swevent and overflow interface") one site was overlooked.Signed-off-by: Peter Zijlstra
Link: http://lkml.kernel.org/r/20110708173442.GB31972@e102144-lin.cambridge.arm.com
Signed-off-by: Ingo Molnar
01 Jul, 2011
1 commit
-
The perf_event overflow handler does not receive any caller-derived
argument, so many callers need to resort to looking up the perf_event
in their local data structure. This is ugly and doesn't scale if a
single callback services many perf_events.Fix by adding a context parameter to perf_event_create_kernel_counter()
(and derived hardware breakpoints APIs) and storing it in the perf_event.
The field can be accessed from the callback as event->overflow_handler_context.
All callers are updated.Signed-off-by: Avi Kivity
Signed-off-by: Peter Zijlstra
Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.com
Signed-off-by: Ingo Molnar
31 May, 2011
2 commits
-
This fixes the A->B/B->A locking dependency, see the warning below.
The function task_exit_notify() is called with (task_exit_notifier)
.rwsem set and then calls sync_buffer() which locks buffer_mutex. In
sync_start() the buffer_mutex was set to prevent notifier functions to
be started before sync_start() is finished. But when registering the
notifier, (task_exit_notifier).rwsem is locked too, but now in
different order than in sync_buffer(). In theory this causes a locking
dependency, what does not occur in practice since task_exit_notify()
is always called after the notifier is registered which means the lock
is already released.However, after checking the notifier functions it turned out the
buffer_mutex in sync_start() is unnecessary. This is because
sync_buffer() may be called from the notifiers even if sync_start()
did not finish yet, the buffers are already allocated but empty. No
need to protect this with the mutex.So we fix this theoretical locking dependency by removing buffer_mutex
in sync_start(). This is similar to the implementation before commit:750d857 oprofile: fix crash when accessing freed task structs
which introduced the locking dependency.
Lockdep warning:
oprofiled/4447 is trying to acquire lock:
(buffer_mutex){+.+...}, at: [] sync_buffer+0x31/0x3ec [oprofile]but task is already holding lock:
((task_exit_notifier).rwsem){++++..}, at: [] __blocking_notifier_call_chain+0x39/0x67which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 ((task_exit_notifier).rwsem){++++..}:
[] lock_acquire+0xf8/0x11e
[] down_write+0x44/0x67
[] blocking_notifier_chain_register+0x52/0x8b
[] profile_event_register+0x2d/0x2f
[] sync_start+0x47/0xc6 [oprofile]
[] oprofile_setup+0x60/0xa5 [oprofile]
[] event_buffer_open+0x59/0x8c [oprofile]
[] __dentry_open+0x1eb/0x308
[] nameidata_to_filp+0x60/0x67
[] do_last+0x5be/0x6b2
[] path_openat+0xc7/0x360
[] do_filp_open+0x3d/0x8c
[] do_sys_open+0x110/0x1a9
[] sys_open+0x20/0x22
[] system_call_fastpath+0x16/0x1b-> #0 (buffer_mutex){+.+...}:
[] __lock_acquire+0x1085/0x1711
[] lock_acquire+0xf8/0x11e
[] mutex_lock_nested+0x63/0x309
[] sync_buffer+0x31/0x3ec [oprofile]
[] task_exit_notify+0x16/0x1a [oprofile]
[] notifier_call_chain+0x37/0x63
[] __blocking_notifier_call_chain+0x50/0x67
[] blocking_notifier_call_chain+0x14/0x16
[] profile_task_exit+0x1a/0x1c
[] do_exit+0x2a/0x6fc
[] do_group_exit+0x83/0xae
[] sys_exit_group+0x17/0x1b
[] system_call_fastpath+0x16/0x1bother info that might help us debug this:
1 lock held by oprofiled/4447:
#0: ((task_exit_notifier).rwsem){++++..}, at: [] __blocking_notifier_call_chain+0x39/0x67stack backtrace:
Pid: 4447, comm: oprofiled Not tainted 2.6.39-00007-gcf4d8d4 #10
Call Trace:
[] print_circular_bug+0xae/0xbc
[] __lock_acquire+0x1085/0x1711
[] ? sync_buffer+0x31/0x3ec [oprofile]
[] lock_acquire+0xf8/0x11e
[] ? sync_buffer+0x31/0x3ec [oprofile]
[] ? mark_lock+0x42f/0x552
[] ? sync_buffer+0x31/0x3ec [oprofile]
[] mutex_lock_nested+0x63/0x309
[] ? sync_buffer+0x31/0x3ec [oprofile]
[] sync_buffer+0x31/0x3ec [oprofile]
[] ? __blocking_notifier_call_chain+0x39/0x67
[] ? __blocking_notifier_call_chain+0x39/0x67
[] task_exit_notify+0x16/0x1a [oprofile]
[] notifier_call_chain+0x37/0x63
[] __blocking_notifier_call_chain+0x50/0x67
[] blocking_notifier_call_chain+0x14/0x16
[] profile_task_exit+0x1a/0x1c
[] do_exit+0x2a/0x6fc
[] ? retint_swapgs+0xe/0x13
[] do_group_exit+0x83/0xae
[] sys_exit_group+0x17/0x1b
[] system_call_fastpath+0x16/0x1bReported-by: Marcin Slusarz
Cc: Carl Love
Cc: # .36+
Signed-off-by: Robert Richter -
After registering the task free notifier we possibly have tasks in our
dying_tasks list. Free them after unregistering the notifier in case
of an error.Cc: # .36+
Signed-off-by: Robert Richter
24 May, 2011
1 commit
-
The oprofile code is still including asm/mutex.h instead of
linux/mutex.h.Signed-off-by: Anton Blanchard
Signed-off-by: Robert Richter
15 Feb, 2011
3 commits
-
This patch is a rework of the hwsampler oprofile implementation that
has been applied recently. Now there are less non-architectural
changes. The only changes are:* introduction of oprofile_add_ext_hw_sample(), and
* removal of section attributes of oprofile_timer_init/_exit().To setup hwsampler for oprofile we need to modify start()/stop()
callbacks and additional hwsampler control files in oprofilefs. We do
not reinitialize the timer or hwsampler mode by restarting calling
init/exit() anymore, instead hwsampler_running is used to switch the
mode directly in oprofile_hwsampler_start/_stop(). For locking reasons
there is also hwsampler_file that reflects the value in oprofilefs.The overall diffstat of the oprofile s390 hwsampler implemenation
shows the low impact to non-architectural code:arch/Kconfig | 3 +
arch/s390/Kconfig | 1 +
arch/s390/oprofile/Makefile | 2 +-
arch/s390/oprofile/hwsampler.c | 1256 ++++++++++++++++++++++++++++++++++
arch/s390/oprofile/hwsampler.h | 113 +++
arch/s390/oprofile/hwsampler_files.c | 162 +++++
arch/s390/oprofile/init.c | 6 +-
drivers/oprofile/cpu_buffer.c | 24 +-
drivers/oprofile/timer_int.c | 4 +-
include/linux/oprofile.h | 7 +
10 files changed, 1567 insertions(+), 11 deletions(-)Acked-by: Heiko Carstens
Signed-off-by: Robert Richter -
OProfile is enhanced to export all files for controlling System z's
hardware sampling, and to invoke hwsampler exported functions to
initialize and use System z's hardware sampling.The patch invokes hwsampler_setup() during oprofile init and exports
following hwsampler files under oprofilefs if hwsampler's setup
succeeded:A new directory for hardware sampling based files
/dev/oprofile/hwsampling/
The userland daemon must explicitly write to the following files
to disable (or enable) hardware based sampling/dev/oprofile/hwsampling/hwsampler
to modify the actual sampling rate
/dev/oprofile/hwsampling/hw_interval
to modify the amount of sampling memory (measured in 4K pages)
/dev/oprofile/hwsampling/hw_sdbt_blocks
The following files are read only and show
the possible minimum sampling rate/dev/oprofile/hwsampling/hw_min_interval
the possible maximum sampling rate
/dev/oprofile/hwsampling/hw_max_interval
The patch splits the oprofile_timer_[init/exit] function so that it
can be also called through user context (oprofilefs) to avoid kernel
oops.Applied with following changes:
* whitespace changes in Makefile and timer_int.cSigned-off-by: Mahesh Salgaonkar
Signed-off-by: Maran Pakkirisamy
Signed-off-by: Heinz Graalfs
Acked-by: Heiko Carstens
Signed-off-by: Robert Richter -
This patch introduces a new oprofile sample add function
(oprofile_add_ext_hw_sample) that can also take task_struct as an
argument, which is used by the hwsampler kernel module when copying
hardware samples to OProfile buffers.Applied with following changes:
* removed #include
* whitespace changes
* removed conditional compilation (CONFIG_HAVE_HWSAMPLER)
* modified order of functions
* fix missing function definition in header fileSigned-off-by: Mahesh Salgaonkar
Signed-off-by: Maran Pakkirisamy
Signed-off-by: Heinz Graalfs
Acked-by: Heiko Carstens
Signed-off-by: Robert Richter
31 Oct, 2010
1 commit
-
…nel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
jump label: Add work around to i386 gcc asm goto bug
x86, ftrace: Use safe noops, drop trap test
jump_label: Fix unaligned traps on sparc.
jump label: Make arch_jump_label_text_poke_early() optional
jump label: Fix error with preempt disable holding mutex
oprofile: Remove deprecated use of flush_scheduled_work()
oprofile: Fix the hang while taking the cpu offline
jump label: Fix deadlock b/w jump_label_mutex vs. text_mutex
jump label: Fix module __init section race* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Check irq_remapped instead of remapping_enabled in destroy_irq()
30 Oct, 2010
1 commit
-
…l/git/rostedt/linux-2.6-trace into perf/urgent
29 Oct, 2010
2 commits
-
flush_scheduled_work() is deprecated and scheduled to be removed.
sync_stop() currently cancels cpu_buffer works inside buffer_mutex and
flushes the system workqueue outside. Instead, split end_cpu_work()
into two parts - stopping further work enqueues and flushing works -
and do the former inside buffer_mutex and latter outside.For stable kernels v2.6.35.y and v2.6.36.y.
Signed-off-by: Tejun Heo
Cc: stable@kernel.org
Signed-off-by: Robert Richter -
The kernel build with CONFIG_OPROFILE and CPU_HOTPLUG enabled.
The oprofile is initialised using system timer in absence of hardware
counters supports. Oprofile isn't started from userland.In this setup while doing a CPU offline the kernel hangs in infinite
for loop inside lock_hrtimer_base() functionThis happens because as part of oprofile_cpu_notify(, it tries to
stop an hrtimer which was never started. These per-cpu hrtimers
are started when the oprfile is started.
echo 1 > /dev/oprofile/enableThis problem also existwhen the cpu is booted with maxcpus parameter
set. When bringing the remaining cpus online the timers are started
even if oprofile is not yet enabled.This patch fix this issue by adding a state variable so that
these hrtimer start/stop is only attempted when oprofile is
startedFor stable kernels v2.6.35.y and v2.6.36.y.
Reported-by: Jan Sebastien
Tested-by: sricharan
Signed-off-by: Santosh Shilimkar
Cc: stable@kernel.org
Signed-off-by: Robert Richter
