Messages in this thread | | | From | Waiman Long <> | Subject | Re: [PATCH v3 0/5] mm/memcg: Reduce kmemcache memory accounting overhead | Date | Thu, 15 Apr 2021 09:17:37 -0400 |
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On 4/14/21 11:26 PM, Masayoshi Mizuma wrote: > > Hi Longman, > > Thank you for your patches. > I rerun the benchmark with your patches, it seems that the reduction > is small... The total duration of sendto() and recvfrom() system call > during the benchmark are as follows. > > - sendto > - v5.8 vanilla: 2576.056 msec (100%) > - v5.12-rc7 vanilla: 2988.911 msec (116%) > - v5.12-rc7 with your patches (1-5): 2984.307 msec (115%) > > - recvfrom > - v5.8 vanilla: 2113.156 msec (100%) > - v5.12-rc7 vanilla: 2305.810 msec (109%) > - v5.12-rc7 with your patches (1-5): 2287.351 msec (108%) > > kmem_cache_alloc()/kmem_cache_free() are called around 1,400,000 times during > the benchmark. I ran a loop in a kernel module as following. The duration > is reduced by your patches actually. > > --- > dummy_cache = KMEM_CACHE(dummy, SLAB_ACCOUNT); > for (i = 0; i < 1400000; i++) { > p = kmem_cache_alloc(dummy_cache, GFP_KERNEL); > kmem_cache_free(dummy_cache, p); > } > --- > > - v5.12-rc7 vanilla: 110 msec (100%) > - v5.12-rc7 with your patches (1-5): 85 msec (77%) > > It seems that the reduction is small for the benchmark though... > Anyway, I can see your patches reduce the overhead. > Please feel free to add: > > Tested-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> > > Thanks! > Masa > Thanks for the testing.
I was focusing on your kernel module benchmark in testing my patch. I will try out your pgbench benchmark to see if there can be other tuning that can be done.
BTW, how many numa nodes does your test machine? I did my testing with a 2-socket system. The vmstat caching part may be less effective on systems with more numa nodes. I will try to find a larger 4-socket systems for testing.
Cheers, Longman
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