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authorAndi Kleen <ak@suse.de>2006-06-26 13:59:11 +0200
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-26 10:48:21 -0700
commit495ab9c045e1b0e5c82951b762257fe1c9d81564 (patch)
treef95c376015d340794f64f36fd52f8fa80a1daab7 /kernel
parentd9005b52de7bc9b20afa93e06d3e15843bafc12f (diff)
[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')
-rw-r--r--kernel/sched.c9
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