On Tue, 22 Mar 2022 14:07:55 +0000, Pavel Begunkov wrote:
> This saves one mutex lock/unlock pair per syscall when users do
> submit + getevents. Perf tells that for QD1 iopoll this patch reduces overhead
> on locking from ~4.3% to ~2.6%, iow cuts 1.3% - 1.9% of CPU time. Something
> similar I see in final throughput.
>
> It's a good win for smaller QD, especially considering that io_uring only
> takes about 20-30% of all cycles, the rest goes to syscalling, the block
> layer and below.
>
> [...]
Applied, thanks!
[1/3] io_uring: split off IOPOLL argument verifiction
(no commit info)
[2/3] io_uring: pre-calculate syscall iopolling decision
(no commit info)
[3/3] io_uring: optimise mutex locking for submit+iopoll
(no commit info)
Best regards,
--
Jens Axboe
