Re: 2.4.23-pre VM regression?

From: Marcelo Tosatti
Date: Thu Oct 16 2003 - 08:27:37 EST




On Thu, 16 Oct 2003, Andrea Arcangeli wrote:

> On Thu, Oct 16, 2003 at 09:52:30AM -0200, Marcelo Tosatti wrote:
> >
> > Andrea,
> >
> > Martin first reported problems with "gzip -dc file | less" (280MB file).
> > less was getting killed. He had no swap... I asked him to add some swap
> > and it works now. Fine.
> >
> > The thing is that with 2.4.22 less was being killed, but with 2.4.23-pre
> > he gets:
>
> note, that's a true oom, less needs to allocate 280MB and it doesn't fit
> in ram. there's no bug as far as I can tell.
>
> a `vmstat 1` could confirm that.
>
> > >> And yes, the app was killed:
> > > >
> > > > __alloc_pages: 0-order allocation failed (gfp=0x1d2/0)
> > > > VM: killing process named
> > > > __alloc_pages: 0-order allocation failed (gfp=0x1d2/0)
> > > > VM: killing process gpm
> > > > __alloc_pages: 0-order allocation failed (gfp=0x1d2/0)
> > > > VM: killing process sendmail
> > > > __alloc_pages: 0-order allocation failed (gfp=0x1d2/0)
> > > > VM: killing process less
>
> here the vm keeps killing until 'less' - the real offender - is nuked.
>
> > So a lot of processes which should not get killed are dying. This is
> > really bad. I was afraid it could happen and it did.
> >
> > What now? Resurrect OOM-killer?
>
> the oom killer has the problem I outlined some email ago, with shared
> memory it gets fooled badly etc.., though in a desktop with all tiny
> tasks except the memory-hog (`less` in this case) it works well.

Andrea,

There is no memory. Right. Some task has to be killed. But not small
programs like sendmail/named/etc. What should be killed is "less". That is
clear, right?



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/