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| author | Tejun Heo <tj@kernel.org> | 2014-09-08 09:51:29 +0900 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2014-09-08 09:51:29 +0900 |
| commit | ebd8fef304f99da84d4a52ad056f6137ac9652d4 (patch) | |
| tree | 8fc0366c43264d684b0ade18f82c00182db26040 /lib/percpu_counter.c | |
| parent | 1a4d76076cda69b0abf15463a8cebc172406da25 (diff) | |
| download | lwn-ebd8fef304f99da84d4a52ad056f6137ac9652d4.tar.gz lwn-ebd8fef304f99da84d4a52ad056f6137ac9652d4.zip | |
percpu_counter: make percpu_counters_lock irq-safe
percpu_counter is scheduled to grow @gfp support to allow atomic
initialization. This patch makes percpu_counters_lock irq-safe so
that it can be safely used from atomic contexts.
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'lib/percpu_counter.c')
| -rw-r--r-- | lib/percpu_counter.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c index 7dd33577b905..3fde78275cd1 100644 --- a/lib/percpu_counter.c +++ b/lib/percpu_counter.c @@ -115,6 +115,8 @@ EXPORT_SYMBOL(__percpu_counter_sum); int __percpu_counter_init(struct percpu_counter *fbc, s64 amount, struct lock_class_key *key) { + unsigned long flags __maybe_unused; + raw_spin_lock_init(&fbc->lock); lockdep_set_class(&fbc->lock, key); fbc->count = amount; @@ -126,9 +128,9 @@ int __percpu_counter_init(struct percpu_counter *fbc, s64 amount, #ifdef CONFIG_HOTPLUG_CPU INIT_LIST_HEAD(&fbc->list); - spin_lock(&percpu_counters_lock); + spin_lock_irqsave(&percpu_counters_lock, flags); list_add(&fbc->list, &percpu_counters); - spin_unlock(&percpu_counters_lock); + spin_unlock_irqrestore(&percpu_counters_lock, flags); #endif return 0; } @@ -136,15 +138,17 @@ EXPORT_SYMBOL(__percpu_counter_init); void percpu_counter_destroy(struct percpu_counter *fbc) { + unsigned long flags __maybe_unused; + if (!fbc->counters) return; debug_percpu_counter_deactivate(fbc); #ifdef CONFIG_HOTPLUG_CPU - spin_lock(&percpu_counters_lock); + spin_lock_irqsave(&percpu_counters_lock, flags); list_del(&fbc->list); - spin_unlock(&percpu_counters_lock); + spin_unlock_irqrestore(&percpu_counters_lock, flags); #endif free_percpu(fbc->counters); fbc->counters = NULL; @@ -173,7 +177,7 @@ static int percpu_counter_hotcpu_callback(struct notifier_block *nb, return NOTIFY_OK; cpu = (unsigned long)hcpu; - spin_lock(&percpu_counters_lock); + spin_lock_irq(&percpu_counters_lock); list_for_each_entry(fbc, &percpu_counters, list) { s32 *pcount; unsigned long flags; @@ -184,7 +188,7 @@ static int percpu_counter_hotcpu_callback(struct notifier_block *nb, *pcount = 0; raw_spin_unlock_irqrestore(&fbc->lock, flags); } - spin_unlock(&percpu_counters_lock); + spin_unlock_irq(&percpu_counters_lock); #endif return NOTIFY_OK; } |