Sync with F16

Linux 3.1-rc10
Copy nouveau updates patch from F16
Fix deadlock in POSIX cputimer code (rhbz #746485)
This commit is contained in:
Chuck Ebbert 2011-10-19 01:28:40 -04:00
parent 18312c11db
commit e05440cad9
4 changed files with 8624 additions and 4 deletions

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@ -0,0 +1,73 @@
Subject: cputimer: Cure lock inversion
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Mon Oct 17 11:50:30 CEST 2011
There's a lock inversion between the cputimer->lock and rq->lock; notably
the two callchains involved are:
update_rlimit_cpu()
sighand->siglock
set_process_cpu_timer()
cpu_timer_sample_group()
thread_group_cputimer()
cputimer->lock
thread_group_cputime()
task_sched_runtime()
->pi_lock
rq->lock
scheduler_tick()
rq->lock
task_tick_fair()
update_curr()
account_group_exec()
cputimer->lock
Where the first one is enabling a CLOCK_PROCESS_CPUTIME_ID timer, and
the second one is keeping up-to-date.
This problem was introduced by e8abccb7193 ("posix-cpu-timers: Cure
SMP accounting oddities").
Cure the problem by removing the cputimer->lock and rq->lock nesting,
this leaves concurrent enablers doing duplicate work, but the time
wasted should be on the same order otherwise wasted spinning on the
lock and the greater-than assignment filter should ensure we preserve
monotonicity.
Reported-by: Dave Jones <davej@redhat.com>
Reported-by: Simon Kirby <sim@hostway.ca>
Cc: stable@kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
kernel/posix-cpu-timers.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
Index: linux-2.6/kernel/posix-cpu-timers.c
===================================================================
--- linux-2.6.orig/kernel/posix-cpu-timers.c
+++ linux-2.6/kernel/posix-cpu-timers.c
@@ -274,9 +274,7 @@ void thread_group_cputimer(struct task_s
struct task_cputime sum;
unsigned long flags;
- spin_lock_irqsave(&cputimer->lock, flags);
if (!cputimer->running) {
- cputimer->running = 1;
/*
* The POSIX timer interface allows for absolute time expiry
* values through the TIMER_ABSTIME flag, therefore we have
@@ -284,8 +282,11 @@ void thread_group_cputimer(struct task_s
* it.
*/
thread_group_cputime(tsk, &sum);
+ spin_lock_irqsave(&cputimer->lock, flags);
+ cputimer->running = 1;
update_gt_cputime(&cputimer->cputime, &sum);
- }
+ } else
+ spin_lock_irqsave(&cputimer->lock, flags);
*times = cputimer->cputime;
spin_unlock_irqrestore(&cputimer->lock, flags);
}

File diff suppressed because it is too large Load Diff

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@ -51,7 +51,7 @@ Summary: The Linux kernel
# For non-released -rc kernels, this will be prepended with "0.", so
# for example a 3 here will become 0.3
#
%global baserelease 3
%global baserelease 1
%global fedora_build %{baserelease}
# base_sublevel is the kernel version we're starting with and patching
@ -82,7 +82,7 @@ Summary: The Linux kernel
# The next upstream release sublevel (base_sublevel+1)
%define upstream_sublevel %(echo $((%{base_sublevel} + 1)))
# The rc snapshot level
%define rcrev 9
%define rcrev 10
# The git snapshot level
%define gitrev 0
# Set rpm version accordingly
@ -746,6 +746,9 @@ Patch21002: mmc-Always-check-for-lower-base-frequency-quirk-for-.patch
Patch21020: 0001-mm-vmscan-Limit-direct-reclaim-for-higher-order-allo.patch
Patch21021: 0002-mm-Abort-reclaim-compaction-if-compaction-can-procee.patch
# rhbz #746485
Patch21030: cputimer-cure-lock-inversion.patch
%endif
BuildRoot: %{_tmppath}/kernel-%{KVERREL}-root
@ -1369,6 +1372,9 @@ ApplyPatch utrace.patch
ApplyPatch 0001-mm-vmscan-Limit-direct-reclaim-for-higher-order-allo.patch
ApplyPatch 0002-mm-Abort-reclaim-compaction-if-compaction-can-procee.patch
# rhbz #746485
ApplyPatch cputimer-cure-lock-inversion.patch
# END OF PATCH APPLICATIONS
%endif
@ -2077,6 +2083,12 @@ fi
# ||----w |
# || ||
%changelog
* Wed Oct 19 2011 Chuck Ebbert <cebbert@redhat.com>
- Sync with F16
- Linux 3.1-rc10
- Copy nouveau updates patch from F16
- Fix deadlock in POSIX cputimer code (rhbz #746485)
* Tue Oct 18 2011 Josh Boyer <jwboyer@redhat.com>
- Add patch to fix invalid EFI remap calls from Matt Fleming

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@ -1,2 +1,2 @@
398e95866794def22b12dfbc15ce89c0 linux-3.0.tar.bz2
85fd0d4c9701392b6eb9293035726a02 patch-3.1-rc9.bz2
6a91efe6505579a181c5f5e1a68f6c3a patch-3.1-rc10.bz2