Messages in this thread | | | Date | Wed, 23 Nov 2011 08:32:58 -0200 | From | Glauber Costa <> | Subject | Re: [RFC][PATCH 0/3] impelemnt cgroup_(subsys)_disabled in generic. |
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On 11/23/2011 06:28 AM, KAMEZAWA Hiroyuki wrote: > > Now, memory cgroup has 'mem_cgroup_disabled()' in memcontrol.h > > I made a brief trial to use static_branch() for that function. At doing that, > I thought it will be better to implement generic cgroup functions rather > than having memory cgroup's its own one. > > This series consists of 3 patches > 1 .... implement cgroup_xxxx_disabled() in generic. > 2 .... use jump_label for cgroup_xxxx_disabled() > 3 .... remove mem_cgroup_disabled() in memcontrol.c > > And I post this series for getting review/comments. > I'm not sure patches for using jump_label is worth to be merged. > > I did a test to run a loop > while(-) { > mmap(1M) > touch all pages > munmap() > } > > and measured performance score in ROOT cgroup. Here, > > (Before patch) > 182,932,842,128 cycles # 0.000 GHz [33.33%] > 192,711,643,877 instructions # 1.05 insns per cycle [49.99%] > 761,483,416 cache-references [49.98%] > 159,908 cache-misses # 0.021 % of all cache refs [50.00%] > 33,253,084,874 branches [33.34%] > 109,796,792 branch-misses # 0.33% of all branches [33.34%] > > 58.289265709 seconds time elapsed > > (After patch) > Performance counter stats for './malloc 1': > > 183,068,407,487 cycles # 0.000 GHz [33.33%] > 191,834,248,678 instructions # 1.05 insns per cycle [50.00%] > 798,635,028 cache-references [49.98%] > 95,562 cache-misses # 0.012 % of all cache refs [50.00%] > 32,755,318,286 branches [33.34%] > 77,774,624 branch-misses # 0.24% of all branches [33.34%] > > 58.332356996 seconds time elapsed > > There is no differece in 'time' ;) > But I got an impression that 'branch' score gets better in several tests. >
branch and cache misses are a lot smaller as well. I think this is a win.
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