Re: khugepaged: gets stuck when writing to USB flash, 2.6.38-rc2

From: Jindřich Makovička
Date: Sun Feb 13 2011 - 05:47:17 EST


2011/2/4 Andrea Arcangeli <aarcange@xxxxxxxxxx>:
> On Thu, Feb 03, 2011 at 10:16:17PM +0100, JindÅich MakoviÄka wrote:
>> I also tried echo never > Â/sys/kernel/mm/transparent_hugepage/defrag
>> , and it seems preventing the system freeze, but still the copying
>> itself sometimes comes to almost complete stop (GkrellM shows short
>> spikes of tens of kB/s on the USB /dev/sdX). In this case, khugepaged
>> is also in DN. I still didn't observe this problem when disabling THP
>> completely by echo never > enabled .
>
> Ok then you may need this too:
>
> Âecho never > /sys/kernel/mm/transparent_hugepage/khugepaged/defrag
>
> Compaction is likely too heavy so we need to look into that.

Sorry for the delay.

Yes, disabling both defrag settings also solves the problem:

echo never >/sys/kernel/mm/transparent_hugepage/defrag
echo no > /sys/kernel/mm/transparent_hugepage/khugepaged/defrag

--
Jindrich Makovicka
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