From: Peter Zijlstra Provide a method to set a percpu counter to a specified value. Signed-off-by: Peter Zijlstra Signed-off-by: Andrew Morton --- include/linux/percpu_counter.h | 6 ++++++ lib/percpu_counter.c | 14 ++++++++++++++ 2 files changed, 20 insertions(+) diff -puN include/linux/percpu_counter.h~lib-percpu_counter_set include/linux/percpu_counter.h --- a/include/linux/percpu_counter.h~lib-percpu_counter_set +++ a/include/linux/percpu_counter.h @@ -32,6 +32,7 @@ struct percpu_counter { void percpu_counter_init(struct percpu_counter *fbc, s64 amount); void percpu_counter_destroy(struct percpu_counter *fbc); +void percpu_counter_set(struct percpu_counter *fbc, s64 amount); void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch); s64 percpu_counter_sum(struct percpu_counter *fbc); @@ -75,6 +76,11 @@ static inline void percpu_counter_destro { } +static inline void percpu_counter_set(struct percpu_counter *fbc, s64 amount) +{ + fbc->count = amount; +} + #define __percpu_counter_add(fbc, amount, batch) \ percpu_counter_add(fbc, amount) diff -puN lib/percpu_counter.c~lib-percpu_counter_set lib/percpu_counter.c --- a/lib/percpu_counter.c~lib-percpu_counter_set +++ a/lib/percpu_counter.c @@ -14,6 +14,20 @@ static LIST_HEAD(percpu_counters); static DEFINE_MUTEX(percpu_counters_lock); #endif +void percpu_counter_set(struct percpu_counter *fbc, s64 amount) +{ + int cpu; + + spin_lock(&fbc->lock); + for_each_possible_cpu(cpu) { + s32 *pcount = per_cpu_ptr(fbc->counters, cpu); + *pcount = 0; + } + fbc->count = amount; + spin_unlock(&fbc->lock); +} +EXPORT_SYMBOL(percpu_counter_set); + void __percpu_counter_add(struct percpu_counter *fbc, s64 amount, s32 batch) { s64 count; _