Re: ZONE_NORMAL exhaustion (dcache slab)

"Martin J. Bligh" wrote:

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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.

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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).
 

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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.
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