On Sun, 27 Mar 2011 20:26:00 -0700 Ying Han <yinghan@xxxxxxxxxx> wrote: > Two new stats in per-memcg memory.stat which tracks the number of > page faults and number of major page faults. > > "pgfault" > "pgmajfault" > > They are different from "pgpgin"/"pgpgout" stat which count number of > pages charged/discharged to the cgroup and have no meaning of reading/ > writing page to disk. > > It is valuable to track the two stats for both measuring application's > performance as well as the efficiency of the kernel page reclaim path. > Counting pagefaults per process is useful, but we also need the aggregated > value since processes are monitored and controlled in cgroup basis in memcg. > > Functional test: check the total number of pgfault/pgmajfault of all > memcgs and compare with global vmstat value: > > $ cat /proc/vmstat | grep fault > pgfault 1070751 > pgmajfault 553 > > $ cat /dev/cgroup/memory.stat | grep fault > pgfault 1071138 > pgmajfault 553 > total_pgfault 1071142 > total_pgmajfault 553 > > $ cat /dev/cgroup/A/memory.stat | grep fault > pgfault 199 > pgmajfault 0 > total_pgfault 199 > total_pgmajfault 0 > > Performance test: run page fault test(pft) wit 16 thread on faulting in 15G > anon pages in 16G container. There is no regression noticed on the "flt/cpu/s" > > Sample output from pft: > TAG pft:anon-sys-default: > Gb Thr CLine User System Wall flt/cpu/s fault/wsec > 15 16 1 0.69s 230.99s 14.62s 16972.539 268876.196 > > +-------------------------------------------------------------------------+ > N Min Max Median Avg Stddev > x 10 16682.962 17344.027 16913.524 16928.812 166.5362 > + 10 16718.92 17023.453 16907.164 16902.399 88.468851 > No difference proven at 95.0% confidence > > Signed-off-by: Ying Han <yinghan@xxxxxxxxxx> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>