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| author | Andrew Morton <akpm@linux-foundation.org> | 2008-12-09 22:14:14 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-12-10 17:01:52 +0100 |
| commit | 02d211688727ad02bb4555b1aa8ae2de16b21b39 (patch) | |
| tree | 2ee10b2f0cbfb615c40a2df98627426b8543d6cd /lib/percpu_counter.c | |
| parent | revert "percpu counter: clean up percpu_counter_sum_and_set()" (diff) | |
| download | linux-02d211688727ad02bb4555b1aa8ae2de16b21b39.tar.xz linux-02d211688727ad02bb4555b1aa8ae2de16b21b39.zip | |
revert "percpu_counter: new function percpu_counter_sum_and_set"
Revert
commit e8ced39d5e8911c662d4d69a342b9d053eaaac4e
Author: Mingming Cao <cmm@us.ibm.com>
Date: Fri Jul 11 19:27:31 2008 -0400
percpu_counter: new function percpu_counter_sum_and_set
As described in
revert "percpu counter: clean up percpu_counter_sum_and_set()"
the new percpu_counter_sum_and_set() is racy against updates to the
cpu-local accumulators on other CPUs. Revert that change.
This means that ext4 will be slow again. But correct.
Reported-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: <stable@kernel.org> [2.6.27.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/percpu_counter.c')
| -rw-r--r-- | lib/percpu_counter.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/lib/percpu_counter.c b/lib/percpu_counter.c index dba1530a5b29..b255b939bc1b 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; @@ -62,12 +62,7 @@ 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; } - if (set) - fbc->count = ret; - spin_unlock(&fbc->lock); return ret; } |