Messages in this thread | | | From | Jeff Moyer <> | Subject | Re: [PATCH]block: make auto block plug flush threshold per-disk based | Date | Mon, 09 Apr 2012 10:13:12 -0400 |
| |
Jens Axboe <axboe@kernel.dk> writes:
> On 2012-04-06 11:27, Shaohua Li wrote: >> We do auto block plug flush to reduce latency, the threshold is 16 >> requests. This works well if the task is accessing one or two drives. >> The problem is if the task is accessing a raid 0 device and the raid >> disk number is big, say 8 or 16, 16/8 = 2 or 16/16=1, we will have >> heavy lock contention. >> >> This patch makes the threshold per-disk based. The latency should be >> still ok accessing one or two drives. The setup with application >> accessing a lot of drives in the meantime uaually is big machine, >> avoiding lock contention is more important, because any contention >> will actually increase latency. > > Thanks, applied. It should have been per-queue all along, so this > makes a lot of sense.
Yeah, I had noticed this before when looking over the code. Makes sense.
Acked-by: Jeff Moyer <jmoyer@redhat.com>
| |