Re: commit 1c29a32ce65f4cd0f1c causes Bad rss-counter state and firefox-esr crash in linux-next-20240613

From: Andrew Morton
Date: Fri Jun 14 2024 - 13:21:56 EST


On Fri, 14 Jun 2024 08:30:20 -0400 "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx> wrote:

> >
> > > (these are the error messages of several crashes and the error seems to affect
> > > other processes, too (T1))
> > >
> > > The crash can be provoked to appear in ~1min by opening large numbers of tabs in
> > > firefox-esr (by holding pressing ctrl+t for some time). With this I bisected the
> > > error to commit "1c29a32ce65f mm/mmap: use split munmap calls for MAP_FIXED" and
> > > reverting this commit in linux-next-20240613 fixes the issue for me.
> >
> > Thanks, that must have taken a lot of time.
>
> Yes, thank you for all that work and apologies in creating this
> frustrating situation.
>
> Andrew, please drop the set from your branch. I need to write some more
> tests, but I suspect I will need to do some work around the vma_merge()
> function, which is never a fun endeavor.

Dropped, thanks.