Messages in this thread | | | Date | Fri, 16 Mar 2007 10:03:07 +0000 (GMT) | From | Mel Gorman <> | Subject | Re: 2.6.21-rc3-mm1 |
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On Fri, 16 Mar 2007, Mariusz Kozlowski wrote:
> Hello Mel, >
Hi
>>>>>> Today after +- 24h of uptime I found some more page allocation >>>>>> failures ('eth1: Can't allocate skb for Rx'). You'll find more here: >>>>>> >>>>>> http://tuxland.pl/misc/2.6.21-rc3-mm1-page-allocation-failure.txt >>>>>> >>>>>> System wasn't doing anything unusual, as usual ;-) X, some p2p >>>>>> software, firefox+flash playing music. >>>>> >>>>> Do other kernels do this, or is 2.6.21-rc3-mm1 worse? >>>>> >>>>> It is of course a non-fatal problem and will inevitably happen sometimes, >>>>> but we would like the VM to be able to minimise the occurrence of this >>>>> problem. >>>> >>>> Mariusz, I would be interested in finding out if this problem still occurs when >>>> you set min_free_kbytes to 16384 via /proc/sys/vm/min_free_kbytes. I understand >>>> that the problem is not easily reproduced and requiring configuration changes >>>> is far from ideal but it'd allow me to find out if options 2 or 3 below make >>>> sense in advance. >>> >>> After a few hours I can confirm that this happens with >>> >>> $ cat /proc/sys/vm/min_free_kbytes >>> 16384 >>> >>> as well. See the syslog output below. Feel free to mail me to do some more tests. >> >> Ok, great. Well, not great because it's broken, but I know what's going >> on. I was able to reproduce the problem based on your report on my desktop >> and put together a fix for it. Full regression tests are still running but >> it should be in good enough state for you to test. >> >> Without this patch, I got allocation failures within 15 minutes by stressing >> the machine. With the patch below, it's been up an hour and 15 minutes and >> I'm seeing no problems so far. Will keep the machine running a few days to >> see what happens. >> > > [...] > >> Mariusz, please try the following patch. It should not be necessary to >> adjust your min_free_kbytes again but if you see a failure, please try >> with min_free_kbytes set to 16384. Thanks a lot. > > Works for me. min_free_kbytes was left at default 2791. I left the laptop with > X + aMule + azureus + firefox&flash (playing music) + kernel compilation so > the box was pushed a bit. Uptime close to 9 hours and no page allocation > failures. I leave it running some more. If anything pops out you'll know it :-) >
Excellent news.
This patch has a few flaws in it and it failed regression tests on sparsemem so it's far from ready but I know the basic idea appears sound now. I'll work on bringing the patch up to scratch and hopefully send on another version later today.
Thanks a million for testing.
-- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab - 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/
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