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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2016-11-03 15:50:00 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2016-11-09 23:45:26 +0100 |
| commit | 5588f5afb4cfc33eb377b751ba4b97184373e8d6 (patch) | |
| tree | de2211c3767a7a8886f3f5d65526dc3d8a1da90e | |
| parent | 308167fcb330296fc80505a6b11ba0661f38a4cc (diff) | |
| download | lwn-5588f5afb4cfc33eb377b751ba4b97184373e8d6.tar.gz lwn-5588f5afb4cfc33eb377b751ba4b97184373e8d6.zip | |
lib/percpu_counter: Convert to hotplug state machine
Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20161103145021.28528-5-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | include/linux/cpuhotplug.h | 1 | ||||
| -rw-r--r-- | lib/percpu_counter.c | 25 |
2 files changed, 15 insertions, 11 deletions
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index c622ab349af3..04e5f99ffc70 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -33,6 +33,7 @@ enum cpuhp_state { CPUHP_FS_BUFF_DEAD, CPUHP_PRINTK_DEAD, CPUHP_MM_MEMCQ_DEAD, + CPUHP_PERCPU_CNT_DEAD, CPUHP_WORKQUEUE_PREP, CPUHP_POWER_NUMA_PREPARE, CPUHP_HRTIMERS_PREPARE, diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c index 72d36113ccaa..c8cebb137076 100644 --- a/lib/percpu_counter.c +++ b/lib/percpu_counter.c @@ -158,25 +158,21 @@ EXPORT_SYMBOL(percpu_counter_destroy); int percpu_counter_batch __read_mostly = 32; EXPORT_SYMBOL(percpu_counter_batch); -static void compute_batch_value(void) +static int compute_batch_value(unsigned int cpu) { int nr = num_online_cpus(); percpu_counter_batch = max(32, nr*2); + return 0; } -static int percpu_counter_hotcpu_callback(struct notifier_block *nb, - unsigned long action, void *hcpu) +static int percpu_counter_cpu_dead(unsigned int cpu) { #ifdef CONFIG_HOTPLUG_CPU - unsigned int cpu; struct percpu_counter *fbc; - compute_batch_value(); - if (action != CPU_DEAD && action != CPU_DEAD_FROZEN) - return NOTIFY_OK; + compute_batch_value(cpu); - cpu = (unsigned long)hcpu; spin_lock_irq(&percpu_counters_lock); list_for_each_entry(fbc, &percpu_counters, list) { s32 *pcount; @@ -190,7 +186,7 @@ static int percpu_counter_hotcpu_callback(struct notifier_block *nb, } spin_unlock_irq(&percpu_counters_lock); #endif - return NOTIFY_OK; + return 0; } /* @@ -222,8 +218,15 @@ EXPORT_SYMBOL(__percpu_counter_compare); static int __init percpu_counter_startup(void) { - compute_batch_value(); - hotcpu_notifier(percpu_counter_hotcpu_callback, 0); + int ret; + + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "lib/percpu_cnt:online", + compute_batch_value, NULL); + WARN_ON(ret < 0); + ret = cpuhp_setup_state_nocalls(CPUHP_PERCPU_CNT_DEAD, + "lib/percpu_cnt:dead", NULL, + percpu_counter_cpu_dead); + WARN_ON(ret < 0); return 0; } module_init(percpu_counter_startup); |