On Mon, Nov 26, 2018 at 09:35:55AM -0700, Jens Axboe wrote: > If we are issuing a list of requests, we know if we're at the last one. > If we fail issuing, ensure that we call ->commits_rqs() to flush any > potential previous requests. > > Signed-off-by: Jens Axboe <[email protected]> > --- > block/blk-core.c | 2 +- > block/blk-mq.c | 32 ++++++++++++++++++++++++-------- > block/blk-mq.h | 2 +- > 3 files changed, 26 insertions(+), 10 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index c9758d185357..808a65d23f1a 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -1334,7 +1334,7 @@ blk_status_t blk_insert_cloned_request(struct > request_queue *q, struct request * > * bypass a potential scheduler on the bottom device for > * insert. > */ > - return blk_mq_request_issue_directly(rq); > + return blk_mq_request_issue_directly(rq, true); > } > EXPORT_SYMBOL_GPL(blk_insert_cloned_request); > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 6a249bf6ed00..0a12cec0b426 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -1260,6 +1260,14 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, > struct list_head *list, > if (!list_empty(list)) { > bool needs_restart; > > + /* > + * If we didn't flush the entire list, we could have told > + * the driver there was more coming, but that turned out to > + * be a lie. > + */ > + if (q->mq_ops->commit_rqs) > + q->mq_ops->commit_rqs(hctx); > +
Looks you miss to do it for blk_mq_do_dispatch_sched() and blk_mq_do_dispatch_ctx(), in which only one request is added to the rq_list. Maybe we can call the .commit_rqs(hctx) just at the end of blk_mq_sched_dispatch_requests() for cover all non-direct-issue cases. Thanks, Ming
