Re: Possible 6.5 regression: Huge values for "commited memory"

[Helge Deller]

Greg & Sasha,

can you please queue-up this upstream patch for kernel v6.5-stable ?

commit 3cec50490969afd4a76ccee441f747d869ccff77
Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date:   Sat Sep 16 12:31:42 2023 -0700

    vm: fix move_vma() memory accounting being off

Thanks,
Helge


On 9/16/23 23:17, Linus Torvalds wrote:
> On Sat, 16 Sept 2023 at 12:31, Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> > Does the attached patch fix the problem?
>
> So while I didn't confirm the fix myself, I'm pretty sure that was it.
> Getting the return value wrong would cause an incorrect extra
> vm_acct_memory() call in the non-error case when VM_ACCOUNT is set
> (and mean the loss of one in the error case, but the error case never
> happens in practice).
>
> Which then causes 'vm_committed_as' to grow when it shouldn't, and
> causes exactly that "Committed_AS" in /proc/meminfo to be off.
>
> So here's the same patch, but now with a proper commit message etc.
>
> I haven't pushed it out (because it would be lovely to get a
> "Tested-by" for it, and that will make the commit ID change), but I'll
> probably do so later today, with or without confirmation, because it
> does seem to be the problem.
>
>                Linus