Messages in this thread | | | Date | Thu, 21 Jan 2010 21:00:31 +0530 | From | Balbir Singh <> | Subject | Re: [PATCH mmotm] memcg use generic percpu allocator instead of private one |
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On Thursday 21 January 2010 07:37 AM, KAMEZAWA Hiroyuki wrote: > On Wed, 20 Jan 2010 15:07:52 +0530 > Balbir Singh <balbir@linux.vnet.ibm.com> wrote: > >>> This includes no functional changes. >>> >>> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> >> >> >> Before review, could you please post parallel pagefault data on a large >> system, since root now uses these per cpu counters and its overhead is >> now dependent on these counters. Also the data read from root cgroup is >> also dependent on these, could you make sure that is not broken. >> > Hmm, I rewrote test program for avoidng mmap_sem. This version does fork() > instead of pthread_create() and meausre parallel-process page fault speed. > > [Before patch] > [root@bluextal memory]# /root/bin/perf stat -e page-faults,cache-misses --repeat 5 ./multi-fault-fork 8 > > Performance counter stats for './multi-fault-fork 8' (5 runs): > > 45256919 page-faults ( +- 0.851% ) > 602230144 cache-misses ( +- 0.187% ) > > 61.020533723 seconds time elapsed ( +- 0.002% > > [After patch] > [root@bluextal memory]# /root/bin/perf stat -e page-faults,cache-misses --repeat 5 ./multi-fault-fork 8 > > Performance counter stats for './multi-fault-fork 8' (5 runs): > > 46007166 page-faults ( +- 0.339% ) > 599553505 cache-misses ( +- 0.298% ) > > 61.020937843 seconds time elapsed ( +- 0.004% ) > > slightly improved ? But this test program does some extreme behavior and > you can't see difference in real-world applications, I think. > So, I guess this is in error-range in famous (not small) benchmarks.
Looks good, please give me a couple of days to test, I'll revert back with numbers and review.
-- Three Cheers, Balbir Singh
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