03 Nov, 2009
3 commits
-
…/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futex: Fix spurious wakeup for requeue_pi really -
…/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:
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 -
…nel/git/tip/linux-2.6-tip
* '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
30 Oct, 2009
2 commits
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* '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.
29 Oct, 2009
11 commits
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* '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 -
…/git/tip/linux-2.6-tip
* '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 -
…/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:
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 -
…l/git/tip/linux-2.6-tip
* '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
Reported-by: Peter Teoh
Cc: "Eric W. Biederman"
Cc: "Rafael J. Wysocki"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
cgroup_write_X64() and cgroup_write_string() ignore the return value of
strstrip(). it makes small inconsistent behavior.example:
=========================
# cd /mnt/cgroup/hoge
# cat memory.swappiness
60
# echo "59 " > memory.swappiness
# cat memory.swappiness
59
# echo " 58" > memory.swappiness
bash: echo: write error: Invalid argumentThis patch fixes it.
Cc: Li Zefan
Acked-by: Paul Menage
Signed-off-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Since commit 02b51df1b07b4e9ca823c89284e704cadb323cd1 (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:
([] 0x13fe04100)
[] sk_filter+0x9a/0xd0
[] netlink_broadcast+0x2c0/0x53c
[] cn_netlink_send+0x272/0x2b0
[] proc_sid_connector+0xc4/0xd4
[] __set_special_pids+0x58/0x90
[] sys_setsid+0xb4/0xd8
[] sysc_noemu+0x10/0x16
[] 0x41616cb266The 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
Cc: Scott James Remnant
Cc: Matt Helsley
Cc: David S. Miller
Acked-by: Oleg Nesterov
Acked-by: Evgeniy Polyakov
Acked-by: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Rusty Russell
Cc: stable@kernel.org -
kp->arg is always true: it's the contents of that pointer we care about.
Reported-by: Takashi Iwai
Signed-off-by: Rusty Russell
Cc: stable@kernel.org -
e180a6b7759a "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
Cc: Sitsofe Wheeler
Cc: Frederic Weisbecker
Cc: Christof Schmitt
Signed-off-by: Rusty Russell
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:
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
Cc: Peter Zijlstra
Cc: Eric Dumazet
Cc: John Stultz
Cc: Dinakar Guniguntala
LKML-Reference:
Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner
28 Oct, 2009
1 commit
-
Commit 34d76c41 introduced percpu array update_shares_data, size of which
being proportional to NR_CPUS. Unfortunately this blows up ia64 for large
NR_CPUS configuration, as ia64 allows only 64k for .percpu section.Fix this by allocating this array dynamically and keep only pointer to it
percpu.The per-cpu handling doesn't impose significant performance penalty on
potentially contented path in tg_shares_up()....
ffffffff8104337c: 65 48 8b 14 25 20 cd mov %gs:0xcd20,%rdx
ffffffff81043383: 00 00
ffffffff81043385: 48 c7 c0 00 e1 00 00 mov $0xe100,%rax
ffffffff8104338c: 48 c7 45 a0 00 00 00 movq $0x0,-0x60(%rbp)
ffffffff81043393: 00
ffffffff81043394: 48 c7 45 a8 00 00 00 movq $0x0,-0x58(%rbp)
ffffffff8104339b: 00
ffffffff8104339c: 48 01 d0 add %rdx,%rax
ffffffff8104339f: 49 8d 94 24 08 01 00 lea 0x108(%r12),%rdx
ffffffff810433a6: 00
ffffffff810433a7: b9 ff ff ff ff mov $0xffffffff,%ecx
ffffffff810433ac: 48 89 45 b0 mov %rax,-0x50(%rbp)
ffffffff810433b0: bb 00 04 00 00 mov $0x400,%ebx
ffffffff810433b5: 48 89 55 c0 mov %rdx,-0x40(%rbp)
...After:
...
ffffffff8104337c: 65 8b 04 25 28 cd 00 mov %gs:0xcd28,%eax
ffffffff81043383: 00
ffffffff81043384: 48 98 cltq
ffffffff81043386: 49 8d bc 24 08 01 00 lea 0x108(%r12),%rdi
ffffffff8104338d: 00
ffffffff8104338e: 48 8b 15 d3 7f 76 00 mov 0x767fd3(%rip),%rdx # ffffffff817ab368
ffffffff81043395: 48 8b 34 c5 00 ee 6d mov -0x7e921200(,%rax,8),%rsi
ffffffff8104339c: 81
ffffffff8104339d: 48 c7 45 a0 00 00 00 movq $0x0,-0x60(%rbp)
ffffffff810433a4: 00
ffffffff810433a5: b9 ff ff ff ff mov $0xffffffff,%ecx
ffffffff810433aa: 48 89 7d c0 mov %rdi,-0x40(%rbp)
ffffffff810433ae: 48 c7 45 a8 00 00 00 movq $0x0,-0x58(%rbp)
ffffffff810433b5: 00
ffffffff810433b6: bb 00 04 00 00 mov $0x400,%ebx
ffffffff810433bb: 48 01 f2 add %rsi,%rdx
ffffffff810433be: 48 89 55 b0 mov %rdx,-0x50(%rbp)
...Signed-off-by: Jiri Kosina
Acked-by: Ingo Molnar
Signed-off-by: Tejun Heo
24 Oct, 2009
4 commits
-
The cpu argument is not used inside the rb_time_stamp() function.
Plus fix a typo.Signed-off-by: Jiri Olsa
Signed-off-by: Steven Rostedt
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar -
Trivial patch to fix a documentation example and to fix a
comment.Signed-off-by: Jiri Olsa
Signed-off-by: Steven Rostedt
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar -
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
Signed-off-by: Steven Rostedt
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar -
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
Signed-off-by: Steven Rostedt
Cc: Frederic Weisbecker
LKML-Reference:
Signed-off-by: Ingo Molnar
23 Oct, 2009
2 commits
-
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
Cc: Peter Zijlstra
Cc: Mike Galbraith
Cc: Paul Mackerras
Cc: Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker
Cc: Steven Rostedt
LKML-Reference:
Signed-off-by: Ingo Molnar -
…n enabling/disabling swevent hrtimers
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>
22 Oct, 2009
1 commit
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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
Signed-off-by: Linus Torvalds
19 Oct, 2009
1 commit
-
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
16 Oct, 2009
3 commits
-
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
Signed-off-by: Darren Hart
Cc:
Cc: Peter Zijlstra
Cc: Eric Dumazet
Cc: Dinakar Guniguntala
Cc: John Stultz
Cc: Sven-Thorsten Dietrich
Cc: John Kacur
LKML-Reference:
Signed-off-by: Ingo Molnar -
* 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
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:
Signed-off-by: Ingo Molnar
15 Oct, 2009
9 commits
-
For the short term, map synchronize_rcu_expedited() to
synchronize_rcu() for TREE_PREEMPT_RCU and to
synchronize_sched_expedited() for TREE_RCU.Longer term, there needs to be a real expedited grace period for
TREE_PREEMPT_RCU, but candidate patches to date are considerably
more complex and intrusive.Signed-off-by: Paul E. McKenney
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
Cc: npiggin@suse.de
Cc: jens.axboe@oracle.com
LKML-Reference:
Signed-off-by: Ingo Molnar -
As the number of callbacks on a given CPU rises, invoke
force_quiescent_state() only every blimit number of callbacks
(defaults to 10,000), and even then only if no other CPU has
invoked force_quiescent_state() in the meantime.This should fix the performance regression reported by Nick.
Reported-by: Nick Piggin
Signed-off-by: Paul E. McKenney
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
Cc: jens.axboe@oracle.com
LKML-Reference:
Signed-off-by: Ingo Molnar -
* 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 -
…/git/tip/linux-2.6-tip
* '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 -
…l/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix missing kernel-doc notation
Revert "x86, timers: Check for pending timers after (device) interrupts"
sched: Update the clock of runqueue select_task_rq() selected -
…nel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tracing/filters: Fix memory leak when setting a filter
tracing: fix trace_vprintk call -
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
[ Fixed to use 'del_timer_sync()' as noted by Oleg ]
Signed-off-by: Linus Torvalds -
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
Cc: Peter Zijlstra
Cc: Ingo Molnar
CC: Eric Dumazet
CC: Dinakar Guniguntala
CC: John Stultz
Cc: stable@kernel.org
LKML-Reference:
Signed-off-by: Thomas Gleixner -
It basically turns a delayed work into an immediate work, and then waits
for it to finish.
14 Oct, 2009
3 commits
-
Yanmin reported a hackbench regression due to:
> commit de69a80be32445b0a71e8e3b757e584d7beb90f7
> Author: Peter Zijlstra
> Date: Thu Sep 17 09:01:20 2009 +0200
>
> sched: Stop buddies from hogging the systemI 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"
Signed-off-by: Peter Zijlstra
CC: Mike Galbraith
LKML-Reference:
Signed-off-by: Ingo Molnar -
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
Signed-off-by: Paul Mackerras
Cc: Corey Ashford
Cc: Peter Zijlstra
LKML-Reference:
Signed-off-by: Ingo Molnar -
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
Debugged-by: Darren Hart
Signed-off-by: Thomas Gleixner
Cc: Peter Zijlstra
Cc: stable@kernel.org
LKML-Reference:
