Messages in this thread | | | Date | Mon, 7 Sep 2009 20:46:40 +0200 | From | Jens Axboe <> | Subject | Re: BFS vs. mainline scheduler benchmarks and measurements |
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On Mon, Sep 07 2009, Avi Kivity wrote: > On 09/07/2009 12:49 PM, Jens Axboe wrote: >> >> I ran a simple test as well, since I was curious to see how it performed >> wrt interactiveness. One of my pet peeves with the current scheduler is >> that I have to nice compile jobs, or my X experience is just awful while >> the compile is running. >> > > I think the problem is that CFS is optimizing for the wrong thing. It's > trying to be fair to tasks, but these are meaningless building blocks of > jobs, which is what the user sees and measures. Your make -j128 > dominates your interactive task by two orders of magnitude. If the > scheduler attempts to bridge this gap using heuristics, it will fail > badly when it misdetects since it will starve the really important > 100-thread job for a task that was misdetected as interactive.
Agree, I was actually looking into doing joint latency for X number of tasks for the test app. I'll try and do that and see if we can detect something from that.
-- Jens Axboe
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