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| author | Bart Van Assche <bvanassche@acm.org> | 2024-03-13 22:42:18 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-03-13 22:56:14 +0100 |
| commit | 256aab46e31683d76d45ccbedc287b4d3f3e322b (patch) | |
| tree | 68f53d685ad63a8239a06b258b1035ef2e7a9032 /block/mq-deadline.c | |
| parent | block: limit block time caching to in_task() context (diff) | |
| download | linux-256aab46e31683d76d45ccbedc287b4d3f3e322b.tar.xz linux-256aab46e31683d76d45ccbedc287b4d3f3e322b.zip | |
Revert "block/mq-deadline: use correct way to throttling write requests"
The code "max(1U, 3 * (1U << shift) / 4)" comes from the Kyber I/O
scheduler. The Kyber I/O scheduler maintains one internal queue per hwq
and hence derives its async_depth from the number of hwq tags. Using
this approach for the mq-deadline scheduler is wrong since the
mq-deadline scheduler maintains one internal queue for all hwqs
combined. Hence this revert.
Cc: stable@vger.kernel.org
Cc: Damien Le Moal <dlemoal@kernel.org>
Cc: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Cc: Zhiguo Niu <Zhiguo.Niu@unisoc.com>
Fixes: d47f9717e5cf ("block/mq-deadline: use correct way to throttling write requests")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20240313214218.1736147-1-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/mq-deadline.c')
| -rw-r--r-- | block/mq-deadline.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/block/mq-deadline.c b/block/mq-deadline.c index f958e79277b8..02a916ba62ee 100644 --- a/block/mq-deadline.c +++ b/block/mq-deadline.c @@ -646,9 +646,8 @@ static void dd_depth_updated(struct blk_mq_hw_ctx *hctx) struct request_queue *q = hctx->queue; struct deadline_data *dd = q->elevator->elevator_data; struct blk_mq_tags *tags = hctx->sched_tags; - unsigned int shift = tags->bitmap_tags.sb.shift; - dd->async_depth = max(1U, 3 * (1U << shift) / 4); + dd->async_depth = max(1UL, 3 * q->nr_requests / 4); sbitmap_queue_min_shallow_depth(&tags->bitmap_tags, dd->async_depth); } |