From: Subject: patch percpu-counter-clean-up-percpu_counter_sum_and_set.patch added to 2.6.27-stable tree Date: Mon, 19 Apr 2010 10:27:05 -0700 Message-ID: <12716980254063@kroah.org> References: <1268699165-17461-3-git-send-email-tytso@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Cc: , To: cmm@us.ibm.com, akpm@linux-foundation.org, a.p.zijlstra@chello.nl, dev@jaysonking.com, linux-ext4@vger.kernel.org, tytso@mit.edu Return-path: Received: from kroah.org ([198.145.64.141]:48486 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752434Ab0DSRaF (ORCPT ); Mon, 19 Apr 2010 13:30:05 -0400 In-Reply-To: <1268699165-17461-3-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: This is a note to let you know that we have just queued up the patch titled Subject: percpu counter: clean up percpu_counter_sum_and_set() to the 2.6.27-stable tree. Its filename is percpu-counter-clean-up-percpu_counter_sum_and_set.patch A git repo of this tree can be found at http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary >From tytso@mit.edu Mon Apr 19 10:20:04 2010 From: Mingming Cao Date: Mon, 15 Mar 2010 20:25:56 -0400 Subject: percpu counter: clean up percpu_counter_sum_and_set() To: stable@kernel.org Cc: "Theodore Ts'o" , Andrew Morton , Ext4 Developers List , Mingming Cao , "Jayson R. King" Message-ID: <1268699165-17461-3-git-send-email-tytso@mit.edu> From: Mingming Cao commit 1f7c14c62ce63805f9574664a6c6de3633d4a354 upstream. 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 merges these two interfaces into one. Signed-off-by: Mingming Cao Acked-by: Peter Zijlstra Cc: Signed-off-by: Andrew Morton Signed-off-by: "Theodore Ts'o" Signed-off-by: Jayson R. King 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(-) --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -1778,7 +1778,7 @@ ext4_fsblk_t ext4_has_free_blocks(struct #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 */ --- a/include/linux/percpu_counter.h +++ b/include/linux/percpu_counter.h @@ -35,7 +35,7 @@ int percpu_counter_init_irq(struct percp 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(st 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) --- 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_c 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; Patches currently in stable-queue which might be from cmm@us.ibm.com are queue-2.6.27/ext4-retry-block-allocation-if-we-have-free-blocks-left.patch queue-2.6.27/percpu-counter-clean-up-percpu_counter_sum_and_set.patch queue-2.6.27/ext4-retry-block-reservation.patch queue-2.6.27/ext4-add-percpu-dirty-block-accounting.patch