Re: ZONE_NORMAL exhaustion (dcache slab)

From: Andrew Morton (akpm@digeo.com)
Date: Mon Oct 21 2002 - 16:33:42 EST


"Martin J. Bligh" wrote:
>
> >> My big NUMA box went OOM over the weekend and started killing things
> >> for no good reason (2.5.43-mm2). Probably running some background
> >> updatedb for locate thing, not doing any real work.
> >>
> >> meminfo:
> >>
> >
> > Looks like a plain dentry leak to me. Very weird.
> >
> > Did the machine recover and run normally?
>
> Nope, kept OOMing and killing everything .

Something broke.

> > Was it possible to force the dcache to shrink? (a cat /dev/hda1
> > would do that nicely)
>
> Well, I didn't try that, but even looking at man pages got oom killed,
> so I guess not ... were you looking at the cat /dev/hda1 to fill pagecache
> or something? I have 16Gb of highmem (pretty much all ununsed) so
> presumably that'd fill the highmem first (pagecache?)

Blockdevices only use ZONE_NORMAL for their pagecache. That cat will
selectively put pressure on the normal zone (and DMA zone, of course).
 
> > Is it reproducible?
>
> Will try again. Presumably "find /" should do it? ;-)

You must have a lot of files.

Actually, I expect a `find /' will only stat directories,
whereas an `ls -lR /' will stat plain files as well. Same
thing for dcache, but the ls will push the icache harder.

I don't know if updatedb stats regular files. Presumably not.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Wed Oct 23 2002 - 22:00:55 EST