Re: [PATCH RESEND] block: annotate refault stalls from IO submission

[Jens Axboe]

On 8/8/19 1:03 PM, Johannes Weiner wrote:
> psi tracks the time tasks wait for refaulting pages to become
> uptodate, but it does not track the time spent submitting the IO. The
> submission part can be significant if backing storage is contended or
> when cgroup throttling (io.latency) is in effect - a lot of time is
> spent in submit_bio(). In that case, we underreport memory pressure.
> 
> Annotate submit_bio() to account submission time as memory stall when
> the bio is reading userspace workingset pages.

Applied for 5.4.

-- 
Jens Axboe