From 252e0ba6b77dcfae448fa2fbaf796e8a83839e75 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Tue, 16 Oct 2007 23:25:43 -0700 Subject: [PATCH] lib: percpu_counter variable batch Because the current batch setup has an quadric error bound on the counter, allow for an alternative setup. Signed-off-by: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/percpu_counter.h | 10 +++++++++- lib/percpu_counter.c | 6 +++--- 2 files changed, 12 insertions(+), 4 deletions(-) diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h index 438a170187ec..40df86f7a3b4 100644 --- a/include/linux/percpu_counter.h +++ b/include/linux/percpu_counter.h @@ -32,9 +32,14 @@ struct percpu_counter { void percpu_counter_init(struct percpu_counter *fbc, s64 amount); void percpu_counter_destroy(struct percpu_counter *fbc); -void percpu_counter_add(struct percpu_counter *fbc, s32 amount); +void __percpu_counter_add(struct percpu_counter *fbc, s32 amount, s32 batch); s64 percpu_counter_sum(struct percpu_counter *fbc); +static inline void percpu_counter_add(struct percpu_counter *fbc, s32 amount) +{ + __percpu_counter_add(fbc, amount, FBC_BATCH); +} + static inline s64 percpu_counter_read(struct percpu_counter *fbc) { return fbc->count; @@ -70,6 +75,9 @@ static inline void percpu_counter_destroy(struct percpu_counter *fbc) { } +#define __percpu_counter_add(fbc, amount, batch) \ + percpu_counter_add(fbc, amount) + static inline void percpu_counter_add(struct percpu_counter *fbc, s32 amount) { diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c index 5f36ad79a24a..f736d67c64d7 100644 --- a/lib/percpu_counter.c +++ b/lib/percpu_counter.c @@ -14,7 +14,7 @@ static LIST_HEAD(percpu_counters); static DEFINE_MUTEX(percpu_counters_lock); #endif -void percpu_counter_add(struct percpu_counter *fbc, s32 amount) +void __percpu_counter_add(struct percpu_counter *fbc, s32 amount, s32 batch) { long count; s32 *pcount; @@ -22,7 +22,7 @@ void percpu_counter_add(struct percpu_counter *fbc, s32 amount) pcount = per_cpu_ptr(fbc->counters, cpu); count = *pcount + amount; - if (count >= FBC_BATCH || count <= -FBC_BATCH) { + if (count >= batch || count <= -batch) { spin_lock(&fbc->lock); fbc->count += count; *pcount = 0; @@ -32,7 +32,7 @@ void percpu_counter_add(struct percpu_counter *fbc, s32 amount) } put_cpu(); } -EXPORT_SYMBOL(percpu_counter_add); +EXPORT_SYMBOL(__percpu_counter_add); /* * Add up all the per-cpu counts, return the result. This is a more accurate