From: Theodore Ts'o Subject: [PATCH 01/42] percpu counter: clean up percpu_counter_sum_and_set() Date: Thu, 9 Oct 2008 00:05:19 -0400 Message-ID: <1223525160-9887-2-git-send-email-tytso@mit.edu> References: <1223525160-9887-1-git-send-email-tytso@mit.edu> Cc: Mingming Cao , Peter Zijlstra , Andrew Morton , "Theodore Ts'o" To: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from www.church-of-our-saviour.org ([69.25.196.31]:54450 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751052AbYJIEGF (ORCPT ); Thu, 9 Oct 2008 00:06:05 -0400 In-Reply-To: <1223525160-9887-1-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Mingming Cao percpu_counter_sum_and_set() and percpu_counter_sum() is the same except the former updates the global counter after accounting. Since we are taking the fbc->lock to calculate the precise value of the counter in percpu_counter_sum() anyway, it should simply set fbc->count too, as the percpu_counter_sum_and_set() does. This patch merge these two interfaces into one. Signed-off-by: Mingming Cao Cc: Peter Zijlstra Cc: Signed-off-by: Andrew Morton Signed-off-by: "Theodore Ts'o" --- fs/ext4/balloc.c | 2 +- include/linux/percpu_counter.h | 12 +++--------- lib/percpu_counter.c | 8 +++----- 3 files changed, 7 insertions(+), 15 deletions(-) diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index e9fa960..00a94d5 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -1624,7 +1624,7 @@ ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi, #ifdef CONFIG_SMP if (free_blocks - root_blocks < FBC_BATCH) free_blocks = - percpu_counter_sum_and_set(&sbi->s_freeblocks_counter); + percpu_counter_sum(&sbi->s_freeblocks_counter); #endif if (free_blocks <= root_blocks) /* we don't have free space */ diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h index 2083888..9007ccd 100644 --- a/include/linux/percpu_counter.h +++ b/include/linux/percpu_counter.h @@ -35,7 +35,7 @@ int percpu_counter_init_irq(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, int set); +s64 __percpu_counter_sum(struct percpu_counter *fbc); static inline void percpu_counter_add(struct percpu_counter *fbc, s64 amount) { @@ -44,19 +44,13 @@ static inline void percpu_counter_add(struct percpu_counter *fbc, s64 amount) static inline s64 percpu_counter_sum_positive(struct percpu_counter *fbc) { - s64 ret = __percpu_counter_sum(fbc, 0); + s64 ret = __percpu_counter_sum(fbc); return ret < 0 ? 0 : ret; } -static inline s64 percpu_counter_sum_and_set(struct percpu_counter *fbc) -{ - return __percpu_counter_sum(fbc, 1); -} - - static inline s64 percpu_counter_sum(struct percpu_counter *fbc) { - return __percpu_counter_sum(fbc, 0); + return __percpu_counter_sum(fbc); } static inline s64 percpu_counter_read(struct percpu_counter *fbc) diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c index 4a8ba4b..a866389 100644 --- a/lib/percpu_counter.c +++ b/lib/percpu_counter.c @@ -52,7 +52,7 @@ EXPORT_SYMBOL(__percpu_counter_add); * Add up all the per-cpu counts, return the result. This is a more accurate * but much slower version of percpu_counter_read_positive() */ -s64 __percpu_counter_sum(struct percpu_counter *fbc, int set) +s64 __percpu_counter_sum(struct percpu_counter *fbc) { s64 ret; int cpu; @@ -62,11 +62,9 @@ s64 __percpu_counter_sum(struct percpu_counter *fbc, int set) for_each_online_cpu(cpu) { s32 *pcount = per_cpu_ptr(fbc->counters, cpu); ret += *pcount; - if (set) - *pcount = 0; + *pcount = 0; } - if (set) - fbc->count = ret; + fbc->count = ret; spin_unlock(&fbc->lock); return ret; -- 1.5.6.1.205.ge2c7.dirty