Messages in this thread | | | Date | Mon, 22 Apr 2013 15:12:32 +0800 | From | Simon Jeons <> | Subject | Re: [PATCH 0/10] Reduce system disruption due to kswapd V2 |
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Hi Zlatko, On 04/22/2013 02:54 PM, Zlatko Calusic wrote: > On 22.04.2013 08:43, Simon Jeons wrote: >> Hi Zlatko, >> On 04/22/2013 02:37 PM, Zlatko Calusic wrote: >>> On 12.04.2013 22:07, Zlatko Calusic wrote: >>>> On 12.04.2013 21:40, 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? >>>>> >>>> >>>> Really nothing special. The server is lightly loaded, but it does >>>> enough >>>> reading from the disk so that pagecache is mostly populated and page >>>> reclaiming is active. So, kswapd is no doubt using CPU time gradually, >>>> nothing extraordinary. >>>> >>>> When I sent my reply yesterday, the server uptime was 12 days, and >>>> kswapd had accumulated 4:28 CPU time. Now, approx 24 hours later (13 >>>> days uptime): >>>> >>>> root 23 0.0 0.0 0 0 ? S Mar30 4:52 >>>> [kswapd0] >>>> >>>> I will apply your v3 series soon and see if there's any improvement >>>> wrt >>>> CPU usage, although as I said I don't see that as a big issue. It's >>>> still only 0.013% of available CPU resources (dual core CPU). >>>> >>> >>> JFTR, v3 kswapd uses about 15% more CPU time than v2. 2:50 kswapd CPU >>> time after 6 days 14h uptime. >>> >>> And find attached another debugging graph that shows how ANON pages >>> are privileged in the ZONE_NORMAL on a 4GB machine. Take notice that >>> the number of pages in the ZONE_DMA32 is scaled (/5) to fit the graph >>> nicely. >>> >> >> Could you tell me how you draw this picture? >> > > It's a home made server monitoring system. I just added the code > needed to graph the size of active + inactive LRU lists, per zone and > per type. Check out http://oss.oetiker.ch/rrdtool/
Thanks Zlatko, I successfully install, could you tell me your options?
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