Messages in this thread | | | Subject | Re: [PATCH v2 1/1] sched/uclamp: add SCHED_FLAG_UTIL_CLAMP_RESET flag to reset uclamp | From | Dietmar Eggemann <> | Date | Thu, 15 Oct 2020 13:56:09 +0200 |
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On 14/10/2020 17:00, Yun Hsiang wrote: > On Tue, Oct 13, 2020 at 10:25:48PM +0200, Dietmar Eggemann wrote: >> Hi Yun, >> >> On 12/10/2020 18:31, Yun Hsiang wrote:
[...]
> The tg uclamp value may also change. If top-app's cpu.uclamp.min change > to 50 (~500), then task A's effective uclamp min value is 300 not ~500. > We can set task A's uclamp to 1024, it will be restricted by the tg. > But when task A move to root group, it's effective uclamp min value > will be 1024 not 0. If a task is in root group and it doesn't want to > control it's uclamp, the effective uclamp min value of that task should be 0. > So I think reset functionality is needed.
OK, looks like the intended solution { a) or b) in https://lkml.kernel.org/r/87zh4ohnf9.derkling@matbug.net} is not really feasible.
So we do need the uclamp reset to enable throughout the entire lifetime of task p 'p is !user_defined -> p is controlled by taskgroup hierarchy)'.
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