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| author | Naohiro Aota <naohiro.aota@wdc.com> | 2021-02-04 19:22:10 +0900 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2021-02-09 02:46:07 +0100 |
| commit | 4eef29ef6360d9c3e4be111392e20b70e19171cc (patch) | |
| tree | e30793e811042b270e3b75af4078b7130aaa160c /kernel/task_work.c | |
| parent | 24c0a7227fdfa598badcfc0f735d16745d39e0c4 (diff) | |
btrfs: zoned: do not use async metadata checksum on zoned filesystems
On zoned filesystems, btrfs uses per-fs zoned_meta_io_lock to serialize
the metadata write IOs.
Even with this serialization, write bios sent from btree_write_cache_pages
can be reordered by async checksum workers as these workers are per CPU
and not per zone.
To preserve write bio ordering, we disable async metadata checksum on a
zoned filesystem. This does not result in lower performance with HDDs as
a single CPU core is fast enough to do checksum for a single zone write
stream with the maximum possible bandwidth of the device. If multiple
zones are being written simultaneously, HDD seek overhead lowers the
achievable maximum bandwidth, resulting again in a per zone checksum
serialization not affecting the performance.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'kernel/task_work.c')
0 files changed, 0 insertions, 0 deletions