diff options
| author | Suresh Siddha <suresh.b.siddha@intel.com> | 2010-11-23 16:11:40 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2010-12-13 16:23:56 -0800 |
| commit | 3fb82d56ad003e804923185316236f26b30dfdd5 (patch) | |
| tree | 3ee08bef7cdc0f0ed3b69be5609b53c44299a229 /arch/x86/kernel/smpboot.c | |
| parent | cf7d7e5a1980d1116ee152d25dac382b112b9c17 (diff) | |
| download | lwn-3fb82d56ad003e804923185316236f26b30dfdd5.tar.gz lwn-3fb82d56ad003e804923185316236f26b30dfdd5.zip | |
x86, suspend: Avoid unnecessary smp alternatives switch during suspend/resume
During suspend, we disable all the non boot cpus. And during resume we bring
them all back again. So no need to do alternatives_smp_switch() in between.
On my core 2 based laptop, this speeds up the suspend path by 15msec and the
resume path by 5 msec (suspend/resume speed up differences can be attributed
to the different P-states that the cpu is in during suspend/resume).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <1290557500.4946.8.camel@sbsiddha-MOBL3.sc.intel.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/smpboot.c')
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 083e99d1b7df..837c81e99edf 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1166,6 +1166,20 @@ out: preempt_enable(); } +void arch_disable_nonboot_cpus_begin(void) +{ + /* + * Avoid the smp alternatives switch during the disable_nonboot_cpus(). + * In the suspend path, we will be back in the SMP mode shortly anyways. + */ + skip_smp_alternatives = true; +} + +void arch_disable_nonboot_cpus_end(void) +{ + skip_smp_alternatives = false; +} + void arch_enable_nonboot_cpus_begin(void) { set_mtrr_aps_delayed_init(); |