Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cpu offlining patch from Ingo Molnar:
 "This tree includes a single commit that speeds up x86 suspend/resume
  by replacing a naive 100msec sleep based polling loop with proper
  completion notification.

  This gives some real suspend/resume benefit on servers with larger
  core counts"

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/smpboot: Speed up suspend/resume by avoiding 100ms sleep for CPU offline during S3
This commit is contained in:
Linus Torvalds 2014-10-13 18:20:39 +02:00
commit f1d0d14120
1 changed files with 12 additions and 11 deletions

View File

@ -102,6 +102,8 @@ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map);
DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
EXPORT_PER_CPU_SYMBOL(cpu_info);
static DEFINE_PER_CPU(struct completion, die_complete);
atomic_t init_deasserted;
/*
@ -1325,26 +1327,24 @@ int native_cpu_disable(void)
return ret;
clear_local_APIC();
init_completion(&per_cpu(die_complete, smp_processor_id()));
cpu_disable_common();
return 0;
}
void native_cpu_die(unsigned int cpu)
{
/* We don't do anything here: idle task is faking death itself. */
unsigned int i;
wait_for_completion_timeout(&per_cpu(die_complete, cpu), HZ);
for (i = 0; i < 10; i++) {
/* They ack this in play_dead by setting CPU_DEAD */
if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
if (system_state == SYSTEM_RUNNING)
pr_info("CPU %u is now offline\n", cpu);
return;
}
msleep(100);
/* They ack this in play_dead() by setting CPU_DEAD */
if (per_cpu(cpu_state, cpu) == CPU_DEAD) {
if (system_state == SYSTEM_RUNNING)
pr_info("CPU %u is now offline\n", cpu);
} else {
pr_err("CPU %u didn't die...\n", cpu);
}
pr_err("CPU %u didn't die...\n", cpu);
}
void play_dead_common(void)
@ -1356,6 +1356,7 @@ void play_dead_common(void)
mb();
/* Ack it */
__this_cpu_write(cpu_state, CPU_DEAD);
complete(&per_cpu(die_complete, smp_processor_id()));
/*
* With physical CPU hotplug, we should halt the cpu