diff options
| author | Andi Kleen <ak@suse.de> | 2006-06-26 13:59:11 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-26 10:48:21 -0700 |
| commit | 495ab9c045e1b0e5c82951b762257fe1c9d81564 (patch) | |
| tree | f95c376015d340794f64f36fd52f8fa80a1daab7 /kernel/sched.c | |
| parent | d9005b52de7bc9b20afa93e06d3e15843bafc12f (diff) | |
| download | lwn-495ab9c045e1b0e5c82951b762257fe1c9d81564.tar.gz lwn-495ab9c045e1b0e5c82951b762257fe1c9d81564.zip | |
[PATCH] i386/x86-64/ia64: Move polling flag into thread_info_status
During some profiling I noticed that default_idle causes a lot of
memory traffic. I think that is caused by the atomic operations
to clear/set the polling flag in thread_info. There is actually
no reason to make this atomic - only the idle thread does it
to itself, other CPUs only read it. So I moved it into ti->status.
Converted i386/x86-64/ia64 for now because that was the easiest
way to fix ACPI which also manipulates these flags in its idle
function.
Cc: Nick Piggin <npiggin@novell.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Len Brown <len.brown@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index f06d059edef5..7d1027a4dd21 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -818,6 +818,11 @@ static void deactivate_task(struct task_struct *p, runqueue_t *rq) * the target CPU. */ #ifdef CONFIG_SMP + +#ifndef tsk_is_polling +#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) +#endif + static void resched_task(task_t *p) { int cpu; @@ -833,9 +838,9 @@ static void resched_task(task_t *p) if (cpu == smp_processor_id()) return; - /* NEED_RESCHED must be visible before we test POLLING_NRFLAG */ + /* NEED_RESCHED must be visible before we test polling */ smp_mb(); - if (!test_tsk_thread_flag(p, TIF_POLLING_NRFLAG)) + if (!tsk_is_polling(p)) smp_send_reschedule(cpu); } #else |