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SubjectRe: [resend][PATCH 4/4] oom: don't ignore rss in nascent mm
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> > > Stupid question.
> > >
> > > Can't we just account these allocations in the old -mm temporary?
> > >
> > > IOW. Please look at the "patch" below. It is of course incomplete
> > > and wrong (to the point inc_mm_counter() is not safe without
> > > SPLIT_RSS_COUNTING), and copy_strings/flush_old_exec are not the
> > > best places to play with mm-counters, just to explain what I mean.
> > >
> > > It is very simple. copy_strings() increments MM_ANONPAGES every
> > > time we add a new page into bprm->vma. This makes this memory
> > > visible to select_bad_process().
> > >
> > > When exec changes ->mm (or if it fails), we change MM_ANONPAGES
> > > counter back.
> > >
> > > Most probably I missed something, but what do you think?
> >
> > Because, If the pages of argv is swapping out when processing execve,
> > This accouing doesn't work.
>
> Why?
>
> If copy_strings() inserts the new page into bprm->vma and then
> this page is swapped out, inc_mm_counter(current->mm, MM_ANONPAGES)
> becomes incorrect, yes. And we can't turn it into MM_SWAPENTS.
>
> But does this really matter? oom_badness() counts MM_ANONPAGES +
> MM_SWAPENTS, and result is the same.

Ah, I got it. I did too strongly get stucked correct accounting. but
you mean it's not must.

Okey, I'll tackle this one at this weekend hopefully.



> > Is this enough explanation? Please don't hesitate say "no". If people
> > don't like my approach, I don't hesitate change my thinking.
>
> Well, certainly I can't say no ;)
>
> But it would be nice to find a more simple fix (if it can work,
> of course).
>
>
> And. I need a simple solution for the older kernels.

Alright. It is certinally considerable one.




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