On 02/06/2017 12:24 PM, Omar Sandoval wrote: > From: Omar Sandoval <[email protected]> > > In blk_mq_sched_dispatch_requests(), we call blk_mq_sched_mark_restart() > after we dispatch requests left over on our hardware queue dispatch > list. This is so we'll go back and dispatch requests from the scheduler. > In this case, it's only necessary to restart the hardware queue that we > are running; there's no reason to run other hardware queues just because > we are using shared tags. > > So, split out blk_mq_sched_mark_restart() into two operations, one for > just the hardware queue and one for the whole request queue. The core > code uses both, and I/O schedulers may also want to use them. > > Signed-off-by: Omar Sandoval <[email protected]> > --- > Patch based on block/for-next. > > block/blk-mq-sched.c | 2 +- > block/blk-mq-sched.h | 25 ++++++++++++++++++------- > block/blk-mq.c | 5 ++++- > 3 files changed, 23 insertions(+), 9 deletions(-) > > diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c > index ee455e7cf9d8..7538565359ea 100644 > --- a/block/blk-mq-sched.c > +++ b/block/blk-mq-sched.c > @@ -201,7 +201,7 @@ void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx > *hctx) > * needing a restart in that case. > */ > if (!list_empty(&rq_list)) { > - blk_mq_sched_mark_restart(hctx); > + blk_mq_sched_mark_restart_hctx(hctx); > blk_mq_dispatch_rq_list(hctx, &rq_list);
What if we dispatched nothing on this hardware queue, and it currently doesn't have any IO pending? -- Jens Axboe
