| Message ID | 20181117214354.822-8-axboe@kernel.dk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/7] block: avoid ordered task state change for polled IO | expand |
On Sat, Nov 17, 2018 at 02:43:54PM -0700, Jens Axboe wrote: > Right now we immediately bail if need_resched() is true, but > we need to do at least one loop in case we have entries waiting. > So just invert the need_resched() check, putting it at the > bottom of the loop. Looks good, Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/block/blk-mq.c b/block/blk-mq.c index 0a2847d9248b..4769c975b8c8 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3336,7 +3336,7 @@ static int __blk_mq_poll(struct blk_mq_hw_ctx *hctx, bool spin) hctx->poll_considered++; state = current->state; - while (!need_resched()) { + do { int ret; hctx->poll_invoked++; @@ -3356,7 +3356,7 @@ static int __blk_mq_poll(struct blk_mq_hw_ctx *hctx, bool spin) if (ret < 0 || !spin) break; cpu_relax(); - } + } while (!need_resched()); __set_current_state(TASK_RUNNING); return 0;
Right now we immediately bail if need_resched() is true, but we need to do at least one loop in case we have entries waiting. So just invert the need_resched() check, putting it at the bottom of the loop. Signed-off-by: Jens Axboe <axboe@kernel.dk> --- block/blk-mq.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)