Messages in this thread |  | | Date | Mon, 28 Mar 2022 11:24:16 +0200 | Subject | Re: [PATCH 0/6] Add latency_nice priority | From | Dietmar Eggemann <> |
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On 11/03/2022 17:14, Vincent Guittot wrote: > This patchset restarts the work about adding a latency nice priority to > describe the latency tolerance of cfs tasks. > > The patches [1-4] have been done by Parth: > https://lore.kernel.org/lkml/20200228090755.22829-1-parth@linux.ibm.com/ > > I have just rebased and moved the set of latency priority outside the > priority update. I have removed the reviewed tag because the patches > are 2 years old. > > The patches [5-6] use latency nice priority to decide if a cfs task can > preempt the current running task. Patch 5 gives some tests results with > cyclictests and hackbench to highlight the benefit of latency nice > priority for short interactive task or long intensive tasks.
The Android specific `latency_nice` (in Android `latency_sensitive` [latency_nice < 0]) use case `Skip energy aware task placement` favors an idle CPU over the EAS search path for a `latency_sensitive` task.
https://lkml.kernel.org/r/2aa4b838-c298-ec7d-08f3-caa50cc87dc2@arm.com
This is Android proprietary code similar to what we have in find_idlest_group_cpu() in mainline. We talked to the Android folks last week and IMHO they are not convinced that they can switch this to the proposed `latency_nice->tweak preemption` use case.
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