On Fri, Apr 12, 2013 at 08:40:04PM +0100, Mel Gorman wrote: > On Thu, Apr 11, 2013 at 10:55:13PM +0200, Zlatko Calusic wrote: > > On 09.04.2013 13:06, Mel Gorman wrote: > > <SNIP> > > > > - The only slightly negative thing I observed is that with the patch > > applied kswapd burns 10x - 20x more CPU. So instead of about 15 > > seconds, it has now spent more than 4 minutes on one particular > > machine with a quite steady load (after about 12 days of uptime). > > Admittedly, that's still nothing too alarming, but... > > > > Would you happen to know what circumstances trigger the higher CPU > usage? >
There is also a slight possibility it has been fixed in V3 by the proportional scanning changes. In my own parallelio tests I got the following kswapd CPU times from top. 3.9.0-rc6-vanilla 0:05.21 3.9.0-rc6-lessdisrupt-v2r11 0:07.44 3.9.0-rc6-lessdisrupt-v3r6 0:03.21 In v2, I did see slightly higher CPU usage but it was reduced in v3. For a general set of page reclaim tests I got 3.9.0-rc6-vanilla-micro 3:09.51 3.9.0-rc6-lessdisrupt-v2r11 2:57.78 3.9.0-rc6-lessdisrupt-v3r6 1:10.05 In that case, v2 was comparable so unfortunately I was never seeing the 10-20x more CPU that you got. Thanks. -- Mel Gorman SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
