Messages in this thread | | | From | Florian Fainelli <> | Date | Fri, 6 Dec 2013 14:51:00 -0800 | Subject | Re: high kswapd CPU usage when executing binaries from NFS w/ CMA and COMPACTION |
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2013/12/4 Mel Gorman <mgorman@suse.de>: > On Tue, Dec 03, 2013 at 06:30:28PM -0800, Florian Fainelli wrote: >> Hi all, >> >> I am experiencing high kswapd CPU usage on an ARMv7 system running >> 3.8.13 when executing relatively large binaries from NFS. When this >> happens kswapd consumes around 55-60% CPU usage and the applications >> takes a huge time to load. >> > > There were a number of changes made related to how and when kswapd > stalls, particularly when pages are dirty. Brief check confirms that > > git log v3.8..v3.12 --pretty=one --author "Mel Gorman" mm/vmscan.c > > NFS dirty pages are problematic for compaction as dirty pages cannot be > migrated until cleaned. I'd suggest checking if current mainline suffers > the same problem and if not, focus on patches related to dirty page > handling and kswapd throttling in mm/vmscan.c as backport candidates.
I have just backported these patches to 3.8.13 and am still seeing the problem, although kswapd usage dropped considerably (by half approximately). Will keep you updated once I have properly tested current mainline on my platform. Thanks! -- Florian
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