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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-13 18:20:39 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-13 18:20:39 +0200 |
| commit | f1d0d14120a8a6224a8aead925cf4310f48947d5 (patch) | |
| tree | 434b4cfbaa6af2d60861dda334f785d7a335fe31 | |
| parent | bf10fa857f0604865006d9705e63415b9d4e0d62 (diff) | |
| parent | 2ed53c0d6cc99fc712f7c037e41d9ec4eb8d6b08 (diff) | |
| download | linux-f1d0d14120a8a6224a8aead925cf4310f48947d5.tar.bz2 | |
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
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 1c3443d98105..2d5200e56357 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -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 |