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| author | Eric Dumazet <dada1@cosmosbay.com> | 2006-03-24 03:18:10 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-24 07:33:26 -0800 |
| commit | 8a14342683b1e3adcf5f78660a42fcbd95b44a35 (patch) | |
| tree | 332265cb9fe8b1e107864cdb380bf5f6b4bfb840 | |
| parent | 2ecb9e633c5057d1203a59ef3e5c3aaea37c402e (diff) | |
| download | linux-3.10-8a14342683b1e3adcf5f78660a42fcbd95b44a35.tar.gz linux-3.10-8a14342683b1e3adcf5f78660a42fcbd95b44a35.tar.bz2 linux-3.10-8a14342683b1e3adcf5f78660a42fcbd95b44a35.zip | |
[PATCH] HOTPLUG_CPU: avoid hitting too many cachelines in recalc_bh_state()
Instead of using for_each_cpu(i), we can use for_each_online_cpu(i).
When a CPU goes offline (ie removed from online map), it might have a non
null bh_accounting.nr, so this patch adds a transfer of this counter to an
online CPU counter.
We already have a hotcpu_notifier, (function buffer_cpu_notify()), where we
can do this bh_accounting.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | fs/buffer.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index 36c7253bea7..11ca6eb46a3 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -3078,7 +3078,7 @@ static void recalc_bh_state(void) if (__get_cpu_var(bh_accounting).ratelimit++ < 4096) return; __get_cpu_var(bh_accounting).ratelimit = 0; - for_each_cpu(i) + for_each_online_cpu(i) tot += per_cpu(bh_accounting, i).nr; buffer_heads_over_limit = (tot > max_buffer_heads); } @@ -3127,6 +3127,9 @@ static void buffer_exit_cpu(int cpu) brelse(b->bhs[i]); b->bhs[i] = NULL; } + get_cpu_var(bh_accounting).nr += per_cpu(bh_accounting, cpu).nr; + per_cpu(bh_accounting, cpu).nr = 0; + put_cpu_var(bh_accounting); } static int buffer_cpu_notify(struct notifier_block *self, |