Messages in this thread | | | Date | Wed, 20 Sep 2023 00:37:04 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 2/2] sched/eevdf: Use sched_attr::sched_runtime to set request/slice suggestion |
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On Tue, Sep 19, 2023 at 11:07:08PM +0100, Qais Yousef wrote: > On 09/15/23 14:43, peterz@infradead.org wrote: > > Allow applications to directly set a suggested request/slice length using > > sched_attr::sched_runtime. > > I'm probably as eternally confused as ever, but is this going to be the latency > hint too? I find it hard to correlate runtime to latency if it is.
Yes. Think of it as if a task has to save up for it's slice. Shorter slice means a shorter time to save up for the time, means it can run sooner. Longer slice, you get to save up longer.
Some people really want longer slices to reduce cache trashing or held-lock-preemption like things. Oracle, Facebook, or virt thingies.
Other people just want very short activations but wants them quickly.
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