Messages in this thread |  | | From | Alex Shi <> | Subject | [PATCH 0/4] sched: remove cpu_load decay | Date | Tue, 3 Dec 2013 17:05:52 +0800 |
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The cpu_load decays on time according past cpu load of rq. New sched_avg decays on tasks' load of time. Now we has 2 kind decay for cpu_load. That is a kind of redundancy. And increase the system load in sched_tick etc.
This patch removes the cpu_load decay.
There are 5 load_idx used for cpu_load in sched_domain. busy_idx and idle_idx are not zero usually, but newidle_idx, wake_idx and forkexec_idx are all zero on every arch. A shortcut to remove cpu_Load decay in the first patch. just one line patch for this change. :)
I have tested the patchset on my pandaES board, 2 cores ARM Cortex A9. hackbench thread/pipe performance increased nearly 8% with this patchset!
latest kernel 527d1511310a89 + this patchset hackbench -T -g 10 -f 40 23.25" 21.7" 23.16" 19.99" 24.24" 21.53" hackbench -p -g 10 -f 40 26.52" 22.48" 23.89" 24.00" 25.65" 23.06" hackbench -P -g 10 -f 40 20.14" 19.37" 19.96" 19.76" 21.76" 21.54"
Daniel tested this patchset on his Core2 2 socket server, the hackbench has no clear regression/improvement. This patchset is also in Fengguang's x86 testing for more than 1 week, and no regression report until now. Fengguang, could I assume there is no regression on Intel platforms? :)
The git tree for this patchset at: git@github.com:alexshi/power-scheduling.git no-load-idx
-- Thanks Alex
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