| Message ID | 20250418163708.442085-2-ming.lei@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | block: unify elevator changing and fix lockdep warning | expand |
Hi, 在 2025/04/19 0:36, Ming Lei 写道: > Move blk_mq_add_queue_tag_set() after blk_mq_map_swqueue(), and publish > this request queue to tagset after everything is setup. > > This way is safe because BLK_MQ_F_TAG_QUEUE_SHARED isn't used by > blk_mq_map_swqueue(), and this flag is mainly checked in fast IO code > path. > > Prepare for removing ->elevator_lock from blk_mq_map_swqueue() which > is supposed to be called when elevator switch isn't possible. I think you mean *is* possible? Or to protect against switching elevator concurrently? > > Reported-by: Nilay Shroff <nilay@linux.ibm.com> > Closes: https://lore.kernel.org/linux-block/567cb7ab-23d6-4cee-a915-c8cdac903ddd@linux.ibm.com/ > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > block/blk-mq.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index e0fe12f1320f..7cda919fafba 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -4561,8 +4561,8 @@ int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, > q->nr_requests = set->queue_depth; > > blk_mq_init_cpu_queues(q, set->nr_hw_queues); > - blk_mq_add_queue_tag_set(set, q); > blk_mq_map_swqueue(q); > + blk_mq_add_queue_tag_set(set, q); > return 0; > > err_hctxs: >
On 4/18/25 10:06 PM, Ming Lei wrote: > Move blk_mq_add_queue_tag_set() after blk_mq_map_swqueue(), and publish > this request queue to tagset after everything is setup. > > This way is safe because BLK_MQ_F_TAG_QUEUE_SHARED isn't used by > blk_mq_map_swqueue(), and this flag is mainly checked in fast IO code > path. > > Prepare for removing ->elevator_lock from blk_mq_map_swqueue() which > is supposed to be called when elevator switch isn't possible. > > Reported-by: Nilay Shroff <nilay@linux.ibm.com> > Closes: https://lore.kernel.org/linux-block/567cb7ab-23d6-4cee-a915-c8cdac903ddd@linux.ibm.com/ > Signed-off-by: Ming Lei <ming.lei@redhat.com> > --- > block/blk-mq.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Looks good to me: Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
diff --git a/block/blk-mq.c b/block/blk-mq.c index e0fe12f1320f..7cda919fafba 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -4561,8 +4561,8 @@ int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, q->nr_requests = set->queue_depth; blk_mq_init_cpu_queues(q, set->nr_hw_queues); - blk_mq_add_queue_tag_set(set, q); blk_mq_map_swqueue(q); + blk_mq_add_queue_tag_set(set, q); return 0; err_hctxs:
Move blk_mq_add_queue_tag_set() after blk_mq_map_swqueue(), and publish this request queue to tagset after everything is setup. This way is safe because BLK_MQ_F_TAG_QUEUE_SHARED isn't used by blk_mq_map_swqueue(), and this flag is mainly checked in fast IO code path. Prepare for removing ->elevator_lock from blk_mq_map_swqueue() which is supposed to be called when elevator switch isn't possible. Reported-by: Nilay Shroff <nilay@linux.ibm.com> Closes: https://lore.kernel.org/linux-block/567cb7ab-23d6-4cee-a915-c8cdac903ddd@linux.ibm.com/ Signed-off-by: Ming Lei <ming.lei@redhat.com> --- block/blk-mq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)