Re: [PATCH 0/2] block: invalidate cached plug timestamp on context switch

[Peter Zijlstra]

On Tue, Jun 16, 2026 at 10:10:31AM -0600, Jens Axboe wrote:
> On 6/16/26 10:08 AM, Jens Axboe wrote:
> > 
> > On Tue, 16 Jun 2026 07:15:16 -0700, Usama Arif wrote:
> >> The details for this are in patch 2. The main reason for this series
> >> is to invalidate the cached timestamp on context switch. This was
> >> done in sched_update_worker() only before which was resulting in
> >> blk-iocost reading stale timestamps and throttling based on wrong
> >> information.
> >>
> >> Patch 1 is a prerequisite to create the invariant that
> >> PF_BLOCK_TS set implies current->plug != NULL.
> >>
> >> [...]
> > 
> > Applied, thanks!
> > 
> > [1/2] kernel/fork: clear PF_BLOCK_TS in copy_process()
> >       commit: fd38b75c4b43295b10d69772a46d1c74dbd6fc81
> > [2/2] block: invalidate cached plug timestamp after task switch
> >       commit: fad156c2af227f42ca796cbb20ddc354a6dd9932
> 
> Note: I tentatively queued this on up as a) it looks good to me (and
> thanks Usama for fixing this!), and b) about to head OOO for a week
> or so. If Peter or any of the sched people disagree, let me know and
> we can deal with it. If not, then I plan on sending this in with the
> usual follow-up merge window fixes next week.

FWIW, looks good to me.