Re: regression/bisected commit 773688a6cb24b0b3c2ba40354d883348a2befa38 make my system completely unusable under high load

From: Andrew Morton
Date: Mon Feb 19 2024 - 18:28:43 EST


On Mon, 19 Feb 2024 11:09:23 +0100 Vlastimil Babka <vbabka@xxxxxxx> wrote:

> On 2/19/24 10:52, Marco Elver wrote:
> > On Mon, 19 Feb 2024 at 10:48, Mikhail Gavrilov
> > <mikhail.v.gavrilov@xxxxxxxxx> wrote:
> >>
> >> On Sat, Feb 3, 2024 at 1:14 AM Mikhail Gavrilov
> >> <mikhail.v.gavrilov@xxxxxxxxx> wrote:
> >> >
> >> > You are right.
> >> > Thanks for digging into it!
> >> >
> >>
> >> This [2] revert is still not merged at least I checked on 4f5e5092fdbf.
> >> Is there any plan to merge it or find another approach?
> >>
> >> [2] https://lore.kernel.org/all/20240118110216.2539519-2-elver@xxxxxxxxxx/
> >
> > I think it's already in -mm and -next. It just takes time, which is a
> > good thing, after all we want to let -next testing confirm nothing is
> > wrong with it.
> >
> > Andrew, is this planned for the next merge window or as a "hot fix"
> > for the current rc? Given it has the right "Fixes" tags it will make
> > it to stable kernels eventually, but I also think that the previous
> > "slow" version is almost unusable on big systems, so it may be
> > worthwhile considering the current rc.
>
> Yeah it would be best to fix in 6.8 to prevent regressions.
>

I'm all confused.

4434a56ec209 ("stackdepot: make fast paths lock-less again") was
mainlined for v6.8-rc3.

That patch Fixed: 108be8def46e ("lib/stackdepot: allow users to evict
stack traces") which was mainlined for v6.8-rc1, so 4434a56ec209 did
not need a cc:stable?