Re: abnormal OOM killer message

From: Minchan Kim
Date: Wed Aug 19 2009 - 02:51:38 EST


On Wed, 19 Aug 2009 15:24:54 +0900
ììê <chungki.woo@xxxxxxxxx> wrote:

> Thank you very much for replys.
>
> But I think it seems not to relate with stale data problem in compcache.
> My question was why last chance to allocate memory was failed.
> When OOM killer is executed, memory state is not a condition to
> execute OOM killer.
> Specially, there are so many pages of order 0. And allocating order is zero.
> I think that last allocating memory should have succeeded.
> That's my worry.

Yes. I agree with you.
Mel. Could you give some comment in this situation ?
Is it possible that order 0 allocation is failed
even there are many pages in buddy ?

>
> -----------------------------------------------------------------------------------------------------------------------------------------------
> page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
> <== this is last chance
> zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET);
> <== uses ALLOC_WMARK_HIGH
> if (page)
> goto got_pg;
>
> out_of_memory(zonelist, gfp_mask, order);
> goto restart;
> -----------------------------------------------------------------------------------------------------------------------------------------------
>
> > Let me have a question.
> > Now the system has 79M as total swap.
> > It's bigger than system memory size.
> > Is it possible in compcache?
> > Can we believe the number?
>
> Yeah, It's possible. 79Mbyte is data size can be swap.
> It's not compressed data size. It's just original data size.

You means your pages with 79M are swap out in compcache's reserved
memory?

>
> Thanks,
> Minchan, Nitin


--
Kind regards,
Minchan Kim
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