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| author | Jens Axboe <axboe@fb.com> | 2017-01-26 12:40:07 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-01-27 08:20:35 -0700 |
| commit | c13660a08c8b3bb49def4374bfd414aaaa564662 (patch) | |
| tree | c7a61741aba75e320838865f176092c07af37f95 /block/blk-mq.c | |
| parent | 50e1dab86aa2c10cbca2f754aae9542169403141 (diff) | |
| download | linux-c13660a08c8b3bb49def4374bfd414aaaa564662.tar.gz linux-c13660a08c8b3bb49def4374bfd414aaaa564662.tar.bz2 linux-c13660a08c8b3bb49def4374bfd414aaaa564662.zip | |
blk-mq-sched: change ->dispatch_requests() to ->dispatch_request()
When we invoke dispatch_requests(), the scheduler empties everything
into the passed in list. This isn't always a good thing, since it
means that we remove items that we could have potentially merged
with.
Change the function to dispatch single requests at the time. If
we do that, we can backoff exactly at the point where the device
can't consume more IO, and leave the rest with the scheduler for
better merging and future dispatch decision making.
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Tested-by: Hannes Reinecke <hare@suse.com>
Diffstat (limited to 'block/blk-mq.c')
| -rw-r--r-- | block/blk-mq.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 21795c6575bc..301ae29fd229 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -998,7 +998,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) */ if (!list_empty(list)) { spin_lock(&hctx->lock); - list_splice(list, &hctx->dispatch); + list_splice_init(list, &hctx->dispatch); spin_unlock(&hctx->lock); /* |