Messages in this thread | | | Date | Fri, 29 Jan 2010 15:46:53 +0000 | From | Mel Gorman <> | Subject | Re: 2.6.32.5 regression: page allocation failure. order:1, |
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On Fri, Jan 29, 2010 at 08:56:20AM -0500, Mark Lord wrote: > Mel Gorman wrote: >> On Thu, Jan 28, 2010 at 09:17:17AM -0500, Mark Lord wrote: > .. >>> Rather than wasting time trying to bisect a full major kernel revision, >>> I think instead I'll just focus on mm/page_alloc.c. > .. >> Well, it might not eve be necessary. In the patch I sent you, it pointed >> the finger at commit 5f8dcc21211a3d4e3a7a5ca366b469fb88117f61 being the >> problem in that case. I believe your problem is a variation of the >> slowdown-in-swapping problem except in your case it manifests as >> GFP_ATOMIC allocations failing. >> >> If the fix does not help you, then I'll take a fresh look at the other >> commits with your particular problem in mind. > .. > > Last night, I installed 2.6.32.7, plus the patch you sent. > So far, no allocation faults. >
Nice one.
> I'll leave it running for another day or so, and then perhaps revert > the one patch to see which of the two things (new kernel, or patch) > is responsible for the difference. >
Thanks, I'd appreciate it. While I'm reasonably confident the problem is with MIGRATE_RESERVE not being free as intended and that the patch fixes it, I'd like more proof.
> The changelog for 2.6.32.7 included something to fix default rsize/wsize > values on NFS. Dunno if this might have had an effect or not, > but when it was failing.. NFS (order 1) was the most frequent case. >
I consider it unlikely that a change in NFS is responsible. The network MTU would remain the same and it's a bigger factor in the size of allocations made. I think it's just a co-incidence that NFS reported the most failures simply because it was responsible for the bulk of network traffic.
Hugh, can I get a signed-off-by on that patch please? I can improve the changelog if you like and send it to Andrew for merging if you like.
-- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab
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