diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2024-04-08 22:36:56 +0300 |
|---|---|---|
| committer | Mike Snitzer <snitzer@kernel.org> | 2024-04-16 18:34:47 +0300 |
| commit | 5268de78e1e61c828174cb2ac7d9c566a97cce69 (patch) | |
| tree | ffe0ac0469daeec112acb98f6f664e22187ac295 /Documentation/admin-guide/device-mapper | |
| parent | 48ef0ba12e6b77a1ce5d09c580c38855b090ae7c (diff) | |
| download | linux-5268de78e1e61c828174cb2ac7d9c566a97cce69.tar.xz | |
dm-crypt: add the optional "high_priority" flag
When WQ_HIGHPRI was used for the dm-crypt kcryptd workqueue it was
reported that dm-crypt performs badly when the system is loaded[1].
Because of reports of audio skipping, dm-crypt stopped using
WQ_HIGHPRI with commit f612b2132db5 (Revert "dm crypt: use WQ_HIGHPRI
for the IO and crypt workqueues").
But it has since been determined that WQ_HIGHPRI provides improved
performance (with reduced latency) for highend systems with much more
resources than those laptop/desktop users which suffered from the use
of WQ_HIGHPRI.
As such, add an option "high_priority" that allows the use of
WQ_HIGHPRI for dm-crypt's workqueues and also sets the write_thread to
nice level MIN_NICE (-20). This commit makes it optional, so that
normal users won't be harmed by it.
[1] https://listman.redhat.com/archives/dm-devel/2023-February/053410.html
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Diffstat (limited to 'Documentation/admin-guide/device-mapper')
| -rw-r--r-- | Documentation/admin-guide/device-mapper/dm-crypt.rst | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/admin-guide/device-mapper/dm-crypt.rst b/Documentation/admin-guide/device-mapper/dm-crypt.rst index aa2d04d95df6..41f5f57f00eb 100644 --- a/Documentation/admin-guide/device-mapper/dm-crypt.rst +++ b/Documentation/admin-guide/device-mapper/dm-crypt.rst @@ -113,6 +113,11 @@ same_cpu_crypt The default is to use an unbound workqueue so that encryption work is automatically balanced between available CPUs. +high_priority + Set dm-crypt workqueues and the writer thread to high priority. This + improves throughput and latency of dm-crypt while degrading general + responsiveness of the system. + submit_from_crypt_cpus Disable offloading writes to a separate thread after encryption. There are some situations where offloading write bios from the |