Re: [Patch] shm cleanups

[Christoph Rohland <hans-christoph.rohland@sap.com>]

Andrea Arcangeli <andrea@suse.de> writes:

> Christoph Rohland <hans-christoph.rohland@sap.com> writes:
> 
> >         if (!(page_map = prepare_highmem_swapout(page_map)))
> > -               goto check_table;
> > +               goto failed;
> 
> This fragment isn't correct. You may fail too early and so you may get
> a task killed due OOM even if you still have lots of regular pages
> queued in a shm segment.

Yes I know it is questionable, but if prepare_highmem_swapout fails we
are in the highmem area and probably most of the rest of shm is also
there. So we only consume a lot of CPU if going on and calling
prepare_highmem_swapout again and again..

prepare_highmem_swapout should not fail (and does not fail very often
in 2.3.26-pre2) In 2.3.25 the machine effectivly locked up when it
failed (and it failed very often).

On 2.3.26-pre2 I do not see a difference between the two versions. So
I do not know which way will be better.

        Christoph
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