| Message ID | 20211221141459.1368176-2-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | blk-mq/dm-rq: support BLK_MQ_F_BLOCKING for dm-rq | expand |
Ming Lei <ming.lei@redhat.com> writes: > Now we reuse queue flag of QUEUE_FLAG_HAS_SRCU for both having srcu and > BLK_MQ_F_BLOCKING. Actually they are two things: one is that srcu is > allocated inside queue, another is that we need to handle blocking > ->queue_rq. So far this way works as expected. > > dm-rq needs to set BLK_MQ_F_BLOCKING if any underlying queue is > marked as BLK_MQ_F_BLOCKING. But dm queue is allocated before tagset > is allocated, one doable way is to always allocate SRCU for dm > queue, then set BLK_MQ_F_BLOCKING for the tagset if it is required, > meantime we can mark the request queue as supporting blocking > ->queue_rq. > > So add one new flag of QUEUE_FLAG_BLOCKING for supporting blocking > ->queue_rq only, and use one private field to describe if request > queue has allocated srcu instance. OK, so you switched to has_srcu because it's an internaly only detail, that makes sense. I think testing for blocking makes more sense than testing for the existence of srcu, so this actually makes the code a bit more readable in my opinion. Reviewed-by: Jeff Moyer <jmoyer@redhat.com> > > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > block/blk-core.c | 2 +- > block/blk-mq.c | 6 +++--- > block/blk-mq.h | 2 +- > block/blk-sysfs.c | 2 +- > include/linux/blkdev.h | 5 +++-- > 5 files changed, 9 insertions(+), 8 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index 10619fd83c1b..7ba806a4e779 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -449,7 +449,7 @@ struct request_queue *blk_alloc_queue(int node_id, bool alloc_srcu) > return NULL; > > if (alloc_srcu) { > - blk_queue_flag_set(QUEUE_FLAG_HAS_SRCU, q); > + q->has_srcu = true; > if (init_srcu_struct(q->srcu) != 0) > goto fail_q; > } > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 0d7c9d3e0329..1408a6b8ccdc 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -259,7 +259,7 @@ EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait); > */ > void blk_mq_wait_quiesce_done(struct request_queue *q) > { > - if (blk_queue_has_srcu(q)) > + if (blk_queue_blocking(q)) > synchronize_srcu(q->srcu); > else > synchronize_rcu(); > @@ -4024,8 +4024,8 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, > int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, > struct request_queue *q) > { > - WARN_ON_ONCE(blk_queue_has_srcu(q) != > - !!(set->flags & BLK_MQ_F_BLOCKING)); > + if (set->flags & BLK_MQ_F_BLOCKING) > + blk_queue_flag_set(QUEUE_FLAG_BLOCKING, q); > > /* mark the queue as mq asap */ > q->mq_ops = set->ops; > diff --git a/block/blk-mq.h b/block/blk-mq.h > index 948791ea2a3e..9601918e2034 100644 > --- a/block/blk-mq.h > +++ b/block/blk-mq.h > @@ -377,7 +377,7 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, > /* run the code block in @dispatch_ops with rcu/srcu read lock held */ > #define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops) \ > do { \ > - if (!blk_queue_has_srcu(q)) { \ > + if (!blk_queue_blocking(q)) { \ > rcu_read_lock(); \ > (dispatch_ops); \ > rcu_read_unlock(); \ > diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c > index e20eadfcf5c8..af89fabb58e3 100644 > --- a/block/blk-sysfs.c > +++ b/block/blk-sysfs.c > @@ -736,7 +736,7 @@ static void blk_free_queue_rcu(struct rcu_head *rcu_head) > struct request_queue *q = container_of(rcu_head, struct request_queue, > rcu_head); > > - kmem_cache_free(blk_get_queue_kmem_cache(blk_queue_has_srcu(q)), q); > + kmem_cache_free(blk_get_queue_kmem_cache(q->has_srcu), q); > } > > /* Unconfigure the I/O scheduler and dissociate from the cgroup controller. */ > diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h > index c80cfaefc0a8..d84abdb294c4 100644 > --- a/include/linux/blkdev.h > +++ b/include/linux/blkdev.h > @@ -365,6 +365,7 @@ struct request_queue { > #endif > > bool mq_sysfs_init_done; > + bool has_srcu; > > #define BLK_MAX_WRITE_HINTS 5 > u64 write_hints[BLK_MAX_WRITE_HINTS]; > @@ -385,7 +386,7 @@ struct request_queue { > /* Keep blk_queue_flag_name[] in sync with the definitions below */ > #define QUEUE_FLAG_STOPPED 0 /* queue is stopped */ > #define QUEUE_FLAG_DYING 1 /* queue being torn down */ > -#define QUEUE_FLAG_HAS_SRCU 2 /* SRCU is allocated */ > +#define QUEUE_FLAG_BLOCKING 2 /* ->queue_rq may block */ > #define QUEUE_FLAG_NOMERGES 3 /* disable merge attempts */ > #define QUEUE_FLAG_SAME_COMP 4 /* complete on same CPU-group */ > #define QUEUE_FLAG_FAIL_IO 5 /* fake timeout */ > @@ -423,7 +424,7 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q); > > #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) > #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) > -#define blk_queue_has_srcu(q) test_bit(QUEUE_FLAG_HAS_SRCU, &(q)->queue_flags) > +#define blk_queue_blocking(q) test_bit(QUEUE_FLAG_BLOCKING, &(q)->queue_flags) > #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) > #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags) > #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags) -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel
diff --git a/block/blk-core.c b/block/blk-core.c index 10619fd83c1b..7ba806a4e779 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -449,7 +449,7 @@ struct request_queue *blk_alloc_queue(int node_id, bool alloc_srcu) return NULL; if (alloc_srcu) { - blk_queue_flag_set(QUEUE_FLAG_HAS_SRCU, q); + q->has_srcu = true; if (init_srcu_struct(q->srcu) != 0) goto fail_q; } diff --git a/block/blk-mq.c b/block/blk-mq.c index 0d7c9d3e0329..1408a6b8ccdc 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -259,7 +259,7 @@ EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait); */ void blk_mq_wait_quiesce_done(struct request_queue *q) { - if (blk_queue_has_srcu(q)) + if (blk_queue_blocking(q)) synchronize_srcu(q->srcu); else synchronize_rcu(); @@ -4024,8 +4024,8 @@ static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set, int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, struct request_queue *q) { - WARN_ON_ONCE(blk_queue_has_srcu(q) != - !!(set->flags & BLK_MQ_F_BLOCKING)); + if (set->flags & BLK_MQ_F_BLOCKING) + blk_queue_flag_set(QUEUE_FLAG_BLOCKING, q); /* mark the queue as mq asap */ q->mq_ops = set->ops; diff --git a/block/blk-mq.h b/block/blk-mq.h index 948791ea2a3e..9601918e2034 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -377,7 +377,7 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx, /* run the code block in @dispatch_ops with rcu/srcu read lock held */ #define __blk_mq_run_dispatch_ops(q, check_sleep, dispatch_ops) \ do { \ - if (!blk_queue_has_srcu(q)) { \ + if (!blk_queue_blocking(q)) { \ rcu_read_lock(); \ (dispatch_ops); \ rcu_read_unlock(); \ diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index e20eadfcf5c8..af89fabb58e3 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -736,7 +736,7 @@ static void blk_free_queue_rcu(struct rcu_head *rcu_head) struct request_queue *q = container_of(rcu_head, struct request_queue, rcu_head); - kmem_cache_free(blk_get_queue_kmem_cache(blk_queue_has_srcu(q)), q); + kmem_cache_free(blk_get_queue_kmem_cache(q->has_srcu), q); } /* Unconfigure the I/O scheduler and dissociate from the cgroup controller. */ diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index c80cfaefc0a8..d84abdb294c4 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -365,6 +365,7 @@ struct request_queue { #endif bool mq_sysfs_init_done; + bool has_srcu; #define BLK_MAX_WRITE_HINTS 5 u64 write_hints[BLK_MAX_WRITE_HINTS]; @@ -385,7 +386,7 @@ struct request_queue { /* Keep blk_queue_flag_name[] in sync with the definitions below */ #define QUEUE_FLAG_STOPPED 0 /* queue is stopped */ #define QUEUE_FLAG_DYING 1 /* queue being torn down */ -#define QUEUE_FLAG_HAS_SRCU 2 /* SRCU is allocated */ +#define QUEUE_FLAG_BLOCKING 2 /* ->queue_rq may block */ #define QUEUE_FLAG_NOMERGES 3 /* disable merge attempts */ #define QUEUE_FLAG_SAME_COMP 4 /* complete on same CPU-group */ #define QUEUE_FLAG_FAIL_IO 5 /* fake timeout */ @@ -423,7 +424,7 @@ bool blk_queue_flag_test_and_set(unsigned int flag, struct request_queue *q); #define blk_queue_stopped(q) test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags) #define blk_queue_dying(q) test_bit(QUEUE_FLAG_DYING, &(q)->queue_flags) -#define blk_queue_has_srcu(q) test_bit(QUEUE_FLAG_HAS_SRCU, &(q)->queue_flags) +#define blk_queue_blocking(q) test_bit(QUEUE_FLAG_BLOCKING, &(q)->queue_flags) #define blk_queue_dead(q) test_bit(QUEUE_FLAG_DEAD, &(q)->queue_flags) #define blk_queue_init_done(q) test_bit(QUEUE_FLAG_INIT_DONE, &(q)->queue_flags) #define blk_queue_nomerges(q) test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
Now we reuse queue flag of QUEUE_FLAG_HAS_SRCU for both having srcu and BLK_MQ_F_BLOCKING. Actually they are two things: one is that srcu is allocated inside queue, another is that we need to handle blocking ->queue_rq. So far this way works as expected. dm-rq needs to set BLK_MQ_F_BLOCKING if any underlying queue is marked as BLK_MQ_F_BLOCKING. But dm queue is allocated before tagset is allocated, one doable way is to always allocate SRCU for dm queue, then set BLK_MQ_F_BLOCKING for the tagset if it is required, meantime we can mark the request queue as supporting blocking ->queue_rq. So add one new flag of QUEUE_FLAG_BLOCKING for supporting blocking ->queue_rq only, and use one private field to describe if request queue has allocated srcu instance. Signed-off-by: Ming Lei <ming.lei@redhat.com> --- block/blk-core.c | 2 +- block/blk-mq.c | 6 +++--- block/blk-mq.h | 2 +- block/blk-sysfs.c | 2 +- include/linux/blkdev.h | 5 +++-- 5 files changed, 9 insertions(+), 8 deletions(-)