Messages in this thread |  | | From | Vincent Guittot <> | Date | Mon, 28 Mar 2022 14:56:06 +0200 | Subject | Re: [PATCH 0/6] Add latency_nice priority |
| |
Hi Dietmar,
On Mon, 28 Mar 2022 at 11:24, Dietmar Eggemann <dietmar.eggemann@arm.com> wrote: > > 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.
Thanks for discussing this with Android folks. It's not always easy to change the behavior of a product and I would be interested to discuss this with them. Sometimes you need a PoC to get convinced
|  |