openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

x86_64: speedup touch_nmi_watchdog 

Avoid dirtying remote cpu's memory if it already has the correct value.

Cc: Andi Kleen <ak@suse.de>
Cc: Konrad Rzeszutek <konrad@darnok.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrew Morton 2007-07-17 04:03:58 -07:00 committed by Linus Torvalds
parent f2890255b0
commit 567f3e422a
1 changed files with 5 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
arch/x86_64/kernel/nmi.c
View File

@ -296,7 +296,7 @@ static DEFINE_PER_CPU(unsigned, last_irq_sum);
static DEFINE_PER_CPU(local_t, alert_counter);
static DEFINE_PER_CPU(int, nmi_touch);
void touch_nmi_watchdog (void)
void touch_nmi_watchdog(void)
{
if (nmi_watchdog > 0) {
unsigned cpu;
@ -306,8 +306,10 @@ void touch_nmi_watchdog (void)
* do it ourselves because the alert count increase is not
* atomic.
*/
for_each_present_cpu (cpu)
per_cpu(nmi_touch, cpu) = 1;
for_each_present_cpu(cpu) {
if (per_cpu(nmi_touch, cpu) != 1)
per_cpu(nmi_touch, cpu) = 1;
}
}
touch_softlockup_watchdog();