From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Bart Van Assche To: Jens Axboe Cc: linux-block@vger.kernel.org, Christoph Hellwig , Bart Van Assche , Ming Lei , Omar Sandoval , Hannes Reinecke , Johannes Thumshirn Subject: [PATCH 5/7] blk-mq: Avoid that blk_mq_mark_tag_wait() triggers a queue stall Date: Thu, 30 Nov 2017 16:08:46 -0800 Message-Id: <20171201000848.2656-6-bart.vanassche@wdc.com> In-Reply-To: <20171201000848.2656-1-bart.vanassche@wdc.com> References: <20171201000848.2656-1-bart.vanassche@wdc.com> List-ID: The blk_mq_sched_restart() call from inside blk_mq_free_request() only runs those queues for which BLK_MQ_S_SCHED_RESTART has been set. Hence set that flag from inside blk_mq_mark_tag_wait() whether or not a queue is shared. Signed-off-by: Bart Van Assche Cc: Ming Lei Cc: Omar Sandoval Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Johannes Thumshirn --- block/blk-mq-sched.c | 2 +- block/blk-mq.c | 4 ++-- block/blk-mq.h | 2 ++ 3 files changed, 5 insertions(+), 3 deletions(-) diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c index c4e0cb5f6f1f..398545d94521 100644 --- a/block/blk-mq-sched.c +++ b/block/blk-mq-sched.c @@ -54,7 +54,7 @@ void blk_mq_sched_assign_ioc(struct request *rq, struct bio *bio) * Mark a hardware queue as needing a restart. For shared queues, maintain * a count of how many hardware queues are marked for restart. */ -static void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx) +void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx) { if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state)) return; diff --git a/block/blk-mq.c b/block/blk-mq.c index 26fec4dfa40f..3e0ce940377f 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1036,9 +1036,9 @@ static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx **hctx, wait_queue_entry_t *wait; bool ret; + blk_mq_sched_mark_restart_hctx(this_hctx); + if (!shared_tags) { - if (!test_bit(BLK_MQ_S_SCHED_RESTART, &this_hctx->state)) - set_bit(BLK_MQ_S_SCHED_RESTART, &this_hctx->state); ret = blk_mq_get_driver_tag(rq, hctx, false); /* * Don't clear RESTART here, someone else could have set it. diff --git a/block/blk-mq.h b/block/blk-mq.h index 6c7c3ff5bf62..eb3c93aeb8b3 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -139,6 +139,8 @@ static inline bool blk_mq_hw_queue_mapped(struct blk_mq_hw_ctx *hctx) void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part, unsigned int inflight[2]); +void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx); + static inline void blk_mq_put_dispatch_budget(struct blk_mq_hw_ctx *hctx) { struct request_queue *q = hctx->queue; -- 2.15.0