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| author | Mikulas Patocka <mpatocka@redhat.com> | 2016-11-23 16:52:01 -0500 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2016-12-08 14:13:04 -0500 |
| commit | d12067f428c037b4575aaeb2be00847fc214c24a (patch) | |
| tree | 7998dcb07191152c9e5ce83d0e44eaece082f1e6 /drivers/md/dm-bufio.c | |
| parent | 9ea61cac0b1ad0c09022f39fd97e9b99a2cfc2dc (diff) | |
| download | blackbird-obmc-linux-d12067f428c037b4575aaeb2be00847fc214c24a.tar.gz blackbird-obmc-linux-d12067f428c037b4575aaeb2be00847fc214c24a.zip | |
dm bufio: don't take the lock in dm_bufio_shrink_count
dm_bufio_shrink_count() is called from do_shrink_slab to find out how many
freeable objects are there. The reported value doesn't have to be precise,
so we don't need to take the dm-bufio lock.
Suggested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-bufio.c')
| -rw-r--r-- | drivers/md/dm-bufio.c | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index b5d3428d109e..9ef88f0e2382 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -1588,18 +1588,9 @@ dm_bufio_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) static unsigned long dm_bufio_shrink_count(struct shrinker *shrink, struct shrink_control *sc) { - struct dm_bufio_client *c; - unsigned long count; - - c = container_of(shrink, struct dm_bufio_client, shrinker); - if (sc->gfp_mask & __GFP_FS) - dm_bufio_lock(c); - else if (!dm_bufio_trylock(c)) - return 0; + struct dm_bufio_client *c = container_of(shrink, struct dm_bufio_client, shrinker); - count = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY]; - dm_bufio_unlock(c); - return count; + return ACCESS_ONCE(c->n_buffers[LIST_CLEAN]) + ACCESS_ONCE(c->n_buffers[LIST_DIRTY]); } /* |
