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authorJens Axboe <axboe@fb.com>2017-01-26 14:42:34 -0700
committerJens Axboe <axboe@fb.com>2017-01-27 08:20:34 -0700
commit50e1dab86aa2c10cbca2f754aae9542169403141 (patch)
tree2e17cd0d604bf63d82e4f8838b57ec579690ca52 /block/blk-mq.c
parent99cf1dc580f0766825395aae4f60ec1d8438f011 (diff)
downloadlinux-0-day-50e1dab86aa2c10cbca2f754aae9542169403141.tar.gz
linux-0-day-50e1dab86aa2c10cbca2f754aae9542169403141.tar.xz
blk-mq-sched: fix starvation for multiple hardware queues and shared tags
If we have both multiple hardware queues and shared tag map between devices, we need to ensure that we propagate the hardware queue restart bit higher up. This is because we can get into a situation where we don't have any IO pending on a hardware queue, yet we fail getting a tag to start new IO. If that happens, it's not enough to mark the hardware queue as needing a restart, we need to bubble that up to the higher level queue as well. 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.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 7118833845854..21795c6575bc6 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -40,7 +40,7 @@ static LIST_HEAD(all_q_list);
/*
* Check if any of the ctx's have pending work in this hardware queue
*/
-static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
+bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
{
return sbitmap_any_bit_set(&hctx->ctx_map) ||
!list_empty_careful(&hctx->dispatch) ||
@@ -345,6 +345,7 @@ void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag);
if (sched_tag != -1)
blk_mq_sched_completed_request(hctx, rq);
+ blk_mq_sched_restart_queues(hctx);
blk_queue_exit(q);
}