linux/arch
Peter Zijlstra 925d519ab8 perf_counter: unify and fix delayed counter wakeup
While going over the wakeup code I noticed delayed wakeups only work
for hardware counters but basically all software counters rely on
them.

This patch unifies and generalizes the delayed wakeup to fix this
issue.

Since we're dealing with NMI context bits here, use a cmpxchg() based
single link list implementation to track counters that have pending
wakeups.

[ This should really be generic code for delayed wakeups, but since we
  cannot use cmpxchg()/xchg() in generic code, I've let it live in the
  perf_counter code. -- Eric Dumazet could use it to aggregate the
  network wakeups. ]

Furthermore, the x86 method of using TIF flags was flawed in that its
quite possible to end up setting the bit on the idle task, loosing the
wakeup.

The powerpc method uses per-cpu storage and does appear to be
sufficient.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090330171023.153932974@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:30:36 +02:00
..
alpha Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
arm Merge branch 'for-next' of git://git.o-hand.com/linux-mfd 2009-04-05 11:38:37 -07:00
avr32 Merge branch 'avr32-arch' of git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6 2009-04-05 11:15:28 -07:00
blackfin Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
cris Merge branch 'for-linus' of git://repo.or.cz/cris-mirror 2009-04-05 11:36:31 -07:00
frv Simplify copy_thread() 2009-04-02 19:04:51 -07:00
h8300 Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
ia64 Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
m32r Simplify copy_thread() 2009-04-02 19:04:51 -07:00
m68k Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
m68knommu Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2009-04-03 09:44:58 -07:00
mips Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
mn10300 Simplify copy_thread() 2009-04-02 19:04:51 -07:00
parisc Merge git://git.kernel.org/pub/scm/linux/kernel/git/kyle/parisc-2.6 2009-04-03 09:52:04 -07:00
powerpc perf_counter: unify and fix delayed counter wakeup 2009-04-06 09:30:36 +02:00
s390 Merge branch 'ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-03 17:33:30 -07:00
sh Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6 2009-04-05 11:15:54 -07:00
sparc Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-cpumask 2009-04-05 10:33:07 -07:00
um Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
x86 perf_counter: unify and fix delayed counter wakeup 2009-04-06 09:30:36 +02:00
xtensa Merge branch 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-04-05 11:04:19 -07:00
.gitignore
Kconfig Merge branch 'tracing/core-v2' into tracing-for-linus 2009-04-02 00:49:02 +02:00