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authorSuresh Siddha <suresh.b.siddha@intel.com>2010-11-23 16:11:40 -0800
committerH. Peter Anvin <hpa@linux.intel.com>2010-12-13 16:23:56 -0800
commit3fb82d56ad003e804923185316236f26b30dfdd5 (patch)
tree3ee08bef7cdc0f0ed3b69be5609b53c44299a229 /arch/x86/kernel/alternative.c
parentcf7d7e5a1980d1116ee152d25dac382b112b9c17 (diff)
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/alternative.c')
-rw-r--r--arch/x86/kernel/alternative.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 5079f24c955..9f98eb400fe 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -353,6 +353,7 @@ void __init_or_module alternatives_smp_module_del(struct module *mod)
mutex_unlock(&smp_alt);
}
+bool skip_smp_alternatives;
void alternatives_smp_switch(int smp)
{
struct smp_alt_module *mod;
@@ -368,7 +369,7 @@ void alternatives_smp_switch(int smp)
printk("lockdep: fixing up alternatives.\n");
#endif
- if (noreplace_smp || smp_alt_once)
+ if (noreplace_smp || smp_alt_once || skip_smp_alternatives)
return;
BUG_ON(!smp && (num_online_cpus() > 1));