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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-03-30 19:07:02 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-06 09:30:36 +0200 |
| commit | 925d519ab82b6dd7aca9420d809ee83819c08db2 (patch) | |
| tree | aa05bd7eb607915aa691d5434ec74521b487b466 /arch/x86/kernel/signal.c | |
| parent | 53cfbf593758916aac41db728f029986a62f1254 (diff) | |
| download | op-kernel-dev-925d519ab82b6dd7aca9420d809ee83819c08db2.zip op-kernel-dev-925d519ab82b6dd7aca9420d809ee83819c08db2.tar.gz | |
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>
Diffstat (limited to 'arch/x86/kernel/signal.c')
| -rw-r--r-- | arch/x86/kernel/signal.c | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 611615a..0a813b1 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -6,7 +6,6 @@ * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes * 2000-2002 x86-64 support by Andi Kleen */ -#include <linux/perf_counter.h> #include <linux/sched.h> #include <linux/mm.h> #include <linux/smp.h> @@ -872,11 +871,6 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) tracehook_notify_resume(regs); } - if (thread_info_flags & _TIF_PERF_COUNTERS) { - clear_thread_flag(TIF_PERF_COUNTERS); - perf_counter_notify(regs); - } - #ifdef CONFIG_X86_32 clear_thread_flag(TIF_IRET); #endif /* CONFIG_X86_32 */ |
