diff options
| author | Alexander Motin <[email protected]> | 2020-12-06 12:55:02 -0500 |
|---|---|---|
| committer | GitHub <[email protected]> | 2020-12-06 09:55:02 -0800 |
| commit | 8136b9d73bda48771ab49b32272b7870b463e6fd (patch) | |
| tree | 9d4fd5672a0f68568edf7e1416fd024c5f25e7fc /module/zfs/vdev_queue.c | |
| parent | 6366ef22404ef1bd0ba26364905e19f2ec7df2a4 (diff) | |
Avoid some spa_has_pending_synctask() calls.
Since 8c4fb36a24 (PR #7795) spa_has_pending_synctask() started to
take two more locks per write inside txg_all_lists_empty(). I am
surprised those pool-wide locks are not contended, but still their
operations are visible in CPU profiles under contended vdev lock.
This commit slightly changes vdev_queue_max_async_writes() flow to
not call the function if we are going to return max_active any way
due to high amount of dirty data. It allows to save some CPU time
exactly when the pool is busy.
Reviewed-by: Ryan Moeller <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-By: Tom Caputi <[email protected]>
Signed-off-by: Alexander Motin <[email protected]>
Closes #11280
Diffstat (limited to 'module/zfs/vdev_queue.c')
| -rw-r--r-- | module/zfs/vdev_queue.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/module/zfs/vdev_queue.c b/module/zfs/vdev_queue.c index 6f3c4208a..02040c3ee 100644 --- a/module/zfs/vdev_queue.c +++ b/module/zfs/vdev_queue.c @@ -338,14 +338,12 @@ vdev_queue_max_async_writes(spa_t *spa) * Sync tasks correspond to interactive user actions. To reduce the * execution time of those actions we push data out as fast as possible. */ - if (spa_has_pending_synctask(spa)) + dirty = dp->dp_dirty_total; + if (dirty > max_bytes || spa_has_pending_synctask(spa)) return (zfs_vdev_async_write_max_active); - dirty = dp->dp_dirty_total; if (dirty < min_bytes) return (zfs_vdev_async_write_min_active); - if (dirty > max_bytes) - return (zfs_vdev_async_write_max_active); /* * linear interpolation: |