| Message ID | 20171201000848.2656-6-bart.vanassche@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Nov 30, 2017 at 04:08:46PM -0800, Bart Van Assche wrote: > 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 <bart.vanassche@wdc.com> > Cc: Ming Lei <ming.lei@redhat.com> > Cc: Omar Sandoval <osandov@fb.com> > Cc: Christoph Hellwig <hch@lst.de> > Cc: Hannes Reinecke <hare@suse.de> > Cc: Johannes Thumshirn <jthumshirn@suse.de> > --- > 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); On the contrary, the above two lines should be removed simply, because this bit has to be set after the req is added to hctx->dispatch_list, otherwise the RESTART for this rq may be missed. Seems it is a issue introduced by f906a6a0f4268(blk-mq: improve tag waiting setup for non-shared tags). And the bit can be set in blk_mq_sched_dispatch_requests() if the following get_driver_tag fails. > 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 >
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;
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 <bart.vanassche@wdc.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Johannes Thumshirn <jthumshirn@suse.de> --- block/blk-mq-sched.c | 2 +- block/blk-mq.c | 4 ++-- block/blk-mq.h | 2 ++ 3 files changed, 5 insertions(+), 3 deletions(-)