On Mon, 31 Jan 2022 15:33:37 -0500, David Jeffery wrote:
> When blk_mq_delay_run_hw_queues sets an hctx to run in the future, it can
> reset the delay length for an already pending delayed work run_work. This
> creates a scenario where multiple hctx may have their queues set to run,
> but if one runs first and finds nothing to do, it can reset the delay of
> another hctx and stall the other hctx's ability to run requests.
>
> To avoid this I/O stall when an hctx's run_work is already pending,
> leave it untouched to run at its current designated time rather than
> extending its delay. The work will still run which keeps closed the race
> calling blk_mq_delay_run_hw_queues is needed for while also avoiding the
> I/O stall.
>
> [...]
Applied, thanks!
[1/1] blk-mq: avoid extending delays of active hctx from blk_mq_delay_run_hw_queues
commit: 8f5fea65b06de1cc51d4fc23fb4d378d1abd6ed7
Best regards,
--
Jens Axboe
