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author | Nathan Huckleberry <nhuck@google.com> | 2022-08-30 21:44:44 +0300 |
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committer | Mike Snitzer <snitzer@kernel.org> | 2022-10-19 00:17:47 +0300 |
commit | afd41fff9c73ccc3757e94ad727d2a9ac4d7f6cb (patch) | |
tree | 236db1c94c01fb1a99a1006205121f5a1f5a3c00 /drivers/md/dm-log-userspace-base.c | |
parent | cea446630feab57f49d47abccf206e9725019cce (diff) | |
download | linux-afd41fff9c73ccc3757e94ad727d2a9ac4d7f6cb.tar.xz |
dm verity: enable WQ_HIGHPRI on verify_wq
WQ_HIGHPRI increases throughput and decreases disk latency when using
dm-verity. This is important in Android for camera startup speed.
The following tests were run by doing 60 seconds of random reads using
a dm-verity device backed by two ramdisks.
Without WQ_HIGHPRI
lat (usec): min=13, max=3947, avg=69.53, stdev=50.55
READ: bw=51.1MiB/s (53.6MB/s), 51.1MiB/s-51.1MiB/s (53.6MB/s-53.6MB/s)
With WQ_HIGHPRI:
lat (usec): min=13, max=7854, avg=31.15, stdev=30.42
READ: bw=116MiB/s (121MB/s), 116MiB/s-116MiB/s (121MB/s-121MB/s)
Further testing was done by measuring how long it takes to open a
camera on an Android device.
Without WQ_HIGHPRI
Total verity work queue wait times (ms):
880.960, 789.517, 898.852
With WQ_HIGHPRI:
Total verity work queue wait times (ms):
528.824, 439.191, 433.300
The average time to open the camera is reduced by 350ms (or 40-50%).
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Diffstat (limited to 'drivers/md/dm-log-userspace-base.c')
0 files changed, 0 insertions, 0 deletions