Commit f1d0d141 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents bf10fa85 2ed53c0d

arch/x86/kernel/smpboot.c

+12 −11
Original line number Diff line number Diff line
@@ -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;



/*
@@ -1325,27 +1327,25 @@ 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 */

	/* 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);

	}

	} else {

		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

CRA Git | Maintained and supported by SUSTech CRA and CCSE