Re: changing timeslice in linux

From: Mike Galbraith
Date: Mon Aug 20 2012 - 01:54:46 EST


On Sun, 2012-08-19 at 11:58 -0700, Xin Tong wrote:
> I have 2 questions about linux 2.6 x86_64 scheduler.
>
> 1. is the default scheduling algorithm SCHED_NORMAL in linux ?

Yes.

> 2. how do i change the time slice in linux source code ?

You shouldn't need to. You can tune "slice" by adjusting
sched_latency_ns and sched_min_granularity_ns, but note that "slice" is
not a fixed quantum. Also note that CFS preemption decisions are based
upon instantaneous state. A task may have received a full (variable)
"slice" of CPU time, but preemption will be triggered only if a more
deserving task is available, so a "slice" is not the "max uninterrupted
CPU time" that you may expect it to be.. but it is somewhat similar.

-Mike

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