Messages in this thread | | | Date | Tue, 30 Dec 2008 13:37:47 -0600 | From | Jayson King <> | Subject | Re: problem with "sched: revert back to per-rq vruntime"? |
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Here's some times using bash, for example. Let me know if there are some other tests I can do.
It shows on vanilla 2.6.28, a huge increase in latency (about 37X to 39X) starting bash -i when the CPU is loaded with 100% nice tasks, relative to idle CPU. But after reverting f9c0b0950d5fd8c8c5af39bc061f27ea8fddcac3 the latency increase is not as great (about 2X).
# running bash -i on vanilla 2.6.28, # with idle CPU [jayson@atlas tmp]$ time bash -i -c 'exit' exit
real 0m0.020s user 0m0.008s sys 0m0.014s [jayson@atlas tmp]$ time bash -i -c 'exit' exit
real 0m0.020s user 0m0.014s sys 0m0.005s [jayson@atlas tmp]$ time bash -i -c 'exit' exit
real 0m0.020s user 0m0.008s sys 0m0.009s
# running bash -i on vanilla 2.6.28, # with 100% nice CPU usage [jayson@atlas tmp]$ time bash -i -c 'exit' exit
real 0m0.753s user 0m0.011s sys 0m0.011s [jayson@atlas tmp]$ time bash -i -c 'exit' exit
real 0m0.752s user 0m0.012s sys 0m0.012s [jayson@atlas tmp]$ time bash -i -c 'exit' exit
real 0m0.786s user 0m0.010s sys 0m0.008s
# running 2.6.28 reverted f9c0b0950d5fd8c8c5af39bc061f27ea8fddcac3, # with idle CPU [jayson@atlas tmp]$ time bash -i -c 'exit' exit
real 0m0.021s user 0m0.012s sys 0m0.007s [jayson@atlas tmp]$ time bash -i -c 'exit' exit
real 0m0.020s user 0m0.012s sys 0m0.011s [jayson@atlas tmp]$ time bash -i -c 'exit' exit
real 0m0.020s user 0m0.011s sys 0m0.012s
# running 2.6.28 reverted f9c0b0950d5fd8c8c5af39bc061f27ea8fddcac3, # with 100% nice CPU usage [jayson@atlas tmp]$ time bash -i -c 'exit' exit
real 0m0.043s user 0m0.010s sys 0m0.009s [jayson@atlas tmp]$ time bash -i -c 'exit' exit
real 0m0.046s user 0m0.011s sys 0m0.007s [jayson@atlas tmp]$ time bash -i -c 'exit' exit
real 0m0.047s user 0m0.011s sys 0m0.006s
Jayson
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