lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

[PATCH] i386/x86-64/ia64: Move polling flag into thread_info_status

Browse Source 
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>
This commit is contained in:
Andi Kleen
2006-06-26 13:59:11 +02:00
committed by Linus Torvalds
parent d9005b52de
commit 495ab9c045
9 changed files with 37 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/acpi/processor_idle.c
View File

@@ -206,11 +206,11 @@ acpi_processor_power_activate(struct acpi_processor *pr,
static void acpi_safe_halt(void)
{
clear_thread_flag(TIF_POLLING_NRFLAG);
current_thread_info()->status &= ~TS_POLLING;
smp_mb__after_clear_bit();
if (!need_resched())
safe_halt();
set_thread_flag(TIF_POLLING_NRFLAG);
current_thread_info()->status |= TS_POLLING;
}
static atomic_t c3_cpu_count;
@@ -330,10 +330,10 @@ static void acpi_processor_idle(void)
* Invoke the current Cx state to put the processor to sleep.
*/
if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
clear_thread_flag(TIF_POLLING_NRFLAG);
current_thread_info()->status &= ~TS_POLLING;
smp_mb__after_clear_bit();
if (need_resched()) {
set_thread_flag(TIF_POLLING_NRFLAG);
current_thread_info()->status |= TS_POLLING;
local_irq_enable();
return;
}
@@ -371,7 +371,7 @@ static void acpi_processor_idle(void)
t2 = inl(acpi_fadt.xpm_tmr_blk.address);
/* Re-enable interrupts */
local_irq_enable();
set_thread_flag(TIF_POLLING_NRFLAG);
current_thread_info()->status |= TS_POLLING;
/* Compute time (ticks) that we were actually asleep */
sleep_ticks =
ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
@@ -411,7 +411,7 @@ static void acpi_processor_idle(void)
/* Re-enable interrupts */
local_irq_enable();
set_thread_flag(TIF_POLLING_NRFLAG);
current_thread_info()->status |= TS_POLLING;
/* Compute time (ticks) that we were actually asleep */
sleep_ticks =
ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;