diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq-sched.c | 9 | ||||
| -rw-r--r-- | block/blk-mq.c | 9 |
2 files changed, 18 insertions, 0 deletions
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index 74cedea56034..7620734d5542 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -77,6 +77,15 @@ void blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx) return; clear_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state); + /* + * Order clearing SCHED_RESTART and list_empty_careful(&hctx->dispatch) + * in blk_mq_run_hw_queue(). Its pair is the barrier in + * blk_mq_dispatch_rq_list(). So dispatch code won't see SCHED_RESTART, + * meantime new request added to hctx->dispatch is missed to check in + * blk_mq_run_hw_queue(). + */ + smp_mb(); + blk_mq_run_hw_queue(hctx, true); } diff --git a/block/blk-mq.c b/block/blk-mq.c index 8f67f0f16ec2..b748d1e63f9c 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1319,6 +1319,15 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list, spin_unlock(&hctx->lock); /* + * Order adding requests to hctx->dispatch and checking + * SCHED_RESTART flag. The pair of this smp_mb() is the one + * in blk_mq_sched_restart(). Avoid restart code path to + * miss the new added requests to hctx->dispatch, meantime + * SCHED_RESTART is observed here. + */ + smp_mb(); + + /* * If SCHED_RESTART was set by the caller of this function and * it is no longer set that means that it was cleared by another * thread and hence that a queue rerun is needed. |