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| author | Matthew Ahrens <mahrens@delphix.com> | 2017-03-28 15:31:49 -0700 |
|---|---|---|
| committer | Prakash Surya <prakash.surya@delphix.com> | 2017-06-07 18:56:23 -0700 |
| commit | dbfd9f930004c390a2ce2cf850c71b4f880eef9c (patch) | |
| tree | 1816685cb776fddc8307aa751627ad7cc8c80a8e /usr/src | |
| parent | 690031d326342fa4ea28b5e80f1ad6a16281519d (diff) | |
| download | illumos-joyent-dbfd9f930004c390a2ce2cf850c71b4f880eef9c.tar.gz | |
8156 dbuf_evict_notify() does not need dbuf_evict_lock
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Diffstat (limited to 'usr/src')
| -rw-r--r-- | usr/src/uts/common/fs/zfs/dbuf.c | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/usr/src/uts/common/fs/zfs/dbuf.c b/usr/src/uts/common/fs/zfs/dbuf.c index 23d4d3b0bf..64700c5ba6 100644 --- a/usr/src/uts/common/fs/zfs/dbuf.c +++ b/usr/src/uts/common/fs/zfs/dbuf.c @@ -561,19 +561,15 @@ dbuf_evict_notify(void) if (tsd_get(zfs_dbuf_evict_key) != NULL) return; + /* + * We check if we should evict without holding the dbuf_evict_lock, + * because it's OK to occasionally make the wrong decision here, + * and grabbing the lock results in massive lock contention. + */ if (refcount_count(&dbuf_cache_size) > dbuf_cache_max_bytes) { - boolean_t evict_now = B_FALSE; - - mutex_enter(&dbuf_evict_lock); - if (refcount_count(&dbuf_cache_size) > dbuf_cache_max_bytes) { - evict_now = dbuf_cache_above_hiwater(); - cv_signal(&dbuf_evict_cv); - } - mutex_exit(&dbuf_evict_lock); - - if (evict_now) { + if (dbuf_cache_above_hiwater()) dbuf_evict_one(); - } + cv_signal(&dbuf_evict_cv); } } |