diff options
| author | Bart Van Assche <[email protected]> | 2024-05-09 10:01:49 -0700 |
|---|---|---|
| committer | Jens Axboe <[email protected]> | 2024-07-02 08:47:45 -0600 |
| commit | 39823b47bbd40502632ffba90ebb34fff7c8b5e8 (patch) | |
| tree | c35fbb19ce7683ca9822f8108bdd0d9942a88422 /scripts/rustdoc_test_builder.rs | |
| parent | 6259151c04d4e0085e00d2dcb471ebdd1778e72e (diff) | |
block/mq-deadline: Fix the tag reservation code
The current tag reservation code is based on a misunderstanding of the
meaning of data->shallow_depth. Fix the tag reservation code as follows:
* By default, do not reserve any tags for synchronous requests because
for certain use cases reserving tags reduces performance. See also
Harshit Mogalapalli, [bug-report] Performance regression with fio
sequential-write on a multipath setup, 2024-03-07
(https://lore.kernel.org/linux-block/[email protected]/)
* Reduce min_shallow_depth to one because min_shallow_depth must be less
than or equal any shallow_depth value.
* Scale dd->async_depth from the range [1, nr_requests] to [1,
bits_per_sbitmap_word].
Cc: Christoph Hellwig <[email protected]>
Cc: Damien Le Moal <[email protected]>
Cc: Zhiguo Niu <[email protected]>
Fixes: 07757588e507 ("block/mq-deadline: Reserve 25% of scheduler tags for synchronous requests")
Signed-off-by: Bart Van Assche <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jens Axboe <[email protected]>
Diffstat (limited to 'scripts/rustdoc_test_builder.rs')
0 files changed, 0 insertions, 0 deletions