Re: 2.6.21 frozen for a few minutes, swapping to disk

[Nick Piggin <nickpiggin@yahoo.com.au>]

Andrew Morton wrote:
> On Tue, 01 May 2007 15:42:30 +1000 Nick Piggin <nickpiggin@yahoo.com.au> wrote:
> 
> 
>>>hm, a genuine oom on an all-ext3 data=ordered i386 system, just like a
>>>million other people.  How very weird.
>>>
>>>I assume all those pages on the LRU are pagecache pages which for some
>>>reason we're unable to reclaim.
>>
>>It looks like it used up all swap? I'd guess a memory leak in some
>>application, or maybe a page refcount leak somewhere.
> 
> 
> yes, I missed that.   The number of mapped pages is tiny so the thing has
> been trying to swap out like.

I didn't quite parse this :)

If the memory is leaking slowly, it could be eventually pushing
everything out to swap without having a large amount of mapped pages.

Or if something is slowly writing stuff to tmpfs, that may not show
up in mapped pages either.


> The question is: how much memory is free after the oom-killing storm?
> If it's "lots" then it's probably an application problem.  If it's
> "not much" then perhaps there's a kernel leak.

Yeah, or a tmpfs filesystem being filled up (what does `df` say?).

-- 
SUSE Labs, Novell Inc.