On Sun, May 30, 2083 at 09:51:06AM +0530, Nitesh Shetty wrote: > This removes the dependency on interrupts to wake up task. Set task > state as TASK_RUNNING, if need_resched() returns true, > while polling for IO completion. > Earlier, polling task used to sleep, relying on interrupt to wake it up. > This made some IO take very long when interrupt-coalescing is enabled in > NVMe. > > Reference: > http://lists.infradead.org/pipermail/linux-nvme/2018-February/015435.html > Signed-off-by: Nitesh Shetty <nj.shetty@xxxxxxxxxxx> > --- > fs/block_dev.c | 16 ++++++++++++---- > fs/direct-io.c | 8 ++++++-- > fs/iomap.c | 10 +++++++--- > 3 files changed, 25 insertions(+), 9 deletions(-) I think it'd be simpler to have blk_poll set it back to running if need_resched is true rather than repeat this patter across all the callers: --- diff --git a/block/blk-mq.c b/block/blk-mq.c index df93102e2149..40285fe1c8ad 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -3164,6 +3164,7 @@ static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq) cpu_relax(); } + set_current_state(TASK_RUNNING); return false; } --
