On Sat, Jun 02, 2018 at 12:59:21PM +0800, Ming Lei wrote: > If the current io scheduler is 'none', the max allowed 'nr_requests' > should be from set->queue_depth, instead of the tags's depth, which > can be adjusted before. > > This patch fixes this issue by using set->queue_depth as the max > allowed 'nr_requests', meantime updating q->nr_requests when switching > to 'none' scheduler. > > Cc: Marco Patalano <[email protected]> > Cc: "Ewan D. Milne" <[email protected]> > Signed-off-by: Ming Lei <[email protected]> > --- > > This issue can be reproduced by the blktests block/021, which will > be posted soon. > > > block/blk-mq-sched.c | 1 + > block/blk-mq-tag.c | 6 ++++-- > 2 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c > index b0f2c2a40a0c..b087d8884a08 100644 > --- a/block/blk-mq-sched.c > +++ b/block/blk-mq-sched.c > @@ -585,6 +585,7 @@ int blk_mq_init_sched(struct request_queue *q, struct > elevator_type *e) > > if (!e) { > q->elevator = NULL; > + q->nr_requests = q->tag_set->queue_depth; > return 0; > } > > diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c > index a4e58fc28a06..a178d862a29a 100644 > --- a/block/blk-mq-tag.c > +++ b/block/blk-mq-tag.c > @@ -423,7 +423,9 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, > struct blk_mq_tags **tagsptr, unsigned int tdepth, > bool can_grow) > { > + struct blk_mq_tag_set *set = hctx->queue->tag_set; > struct blk_mq_tags *tags = *tagsptr; > + unsigned int max_depth; > > if (tdepth <= tags->nr_reserved_tags) > return -EINVAL; > @@ -434,8 +436,8 @@ int blk_mq_tag_update_depth(struct blk_mq_hw_ctx *hctx, > * If we are allowed to grow beyond the original size, allocate > * a new set of tags before freeing the old one. > */ > - if (tdepth > tags->nr_tags) { > - struct blk_mq_tag_set *set = hctx->queue->tag_set; > + max_depth = can_grow ? tags->nr_tags: set->queue_depth; > + if (tdepth > max_depth) { > struct blk_mq_tags *new; > bool ret;
Turns out the change on blk_mq_tag_update_depth() isn't necessary, will post a new one. Thanks, Ming
