From: Dietmar Eggemann <dietmar.eggemann@arm.com>
To: Valentin Schneider <valentin.schneider@arm.com>,
Parth Shah <parth@linux.ibm.com>,
linux-kernel@vger.kernel.org
Cc: peterz@infradead.org, mingo@redhat.com,
vincent.guittot@linaro.org, patrick.bellasi@matbug.net,
qais.yousef@arm.com, pavel@ucw.cz, dhaval.giani@oracle.com,
qperret@qperret.net, David.Laight@ACULAB.COM,
morten.rasmussen@arm.com, pjt@google.com, tj@kernel.org,
viresh.kumar@linaro.org, rafael.j.wysocki@intel.com,
daniel.lezcano@linaro.org
Subject: Re: [RFC 0/3] Introduce per-task latency_tolerance for scheduler hints
Date: Thu, 5 Dec 2019 15:03:51 +0100 [thread overview]
Message-ID: <838f233e-fa4c-d5a3-9b50-69e2e121edda@arm.com> (raw)
In-Reply-To: <c26f7909-0e4e-a897-bf84-0aa9e5389a0d@arm.com>
On 05/12/2019 11:49, Valentin Schneider wrote:
>
> On 05/12/2019 09:24, Dietmar Eggemann wrote:
>> On 25/11/2019 10:46, Parth Shah wrote:
>>> This patch series is based on the discussion started as the "Usecases for
>>> the per-task latency-nice attribute"[1]
>>>
>>> This patch series introduces a new per-task attribute latency_tolerance to
>>> provide the scheduler hints about the latency requirements of the task.
>>
>> I forgot but is there a chance to have this as a per-taskgroup attribute
>> as well?
>>
>
> Peter argued we should go for task attributes first, and then
> cgroup/taskgroups later on:
>
> https://lore.kernel.org/lkml/20190905083127.GA2332@hirez.programming.kicks-ass.net/
OK, I went through this thread again. So Google or we have to provide
the missing per-taskgroup API via cpu controller's attributes (like for
uclamp) for the EAS usecase.
After reading:
https://lore.kernel.org/r/20190905114030.GL2349@hirez.programming.kicks-ass.net
IMHO the following mapping of the existing Android (binary)
latency_sensitive per-taskgroup flag makes sense:
latency_sensitive=1 -> latency_tolerance*[-20 .. -1] (less tolerant,
more sensitive)
latency_sensitive=0 -> latency_tolerance[0 .. 19] (more tolerant, less
sensitive)
Default value is 0 so not latency_sensitive.
* Since we use [-20 .. 19] as values for latency_tolerance we could name
it latency_nice. It's shorter ... ?
next prev parent reply other threads:[~2019-12-05 14:04 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-25 9:46 [RFC 0/3] Introduce per-task latency_tolerance for scheduler hints Parth Shah
2019-11-25 9:46 ` [RFC 1/3] Introduce latency-tolerance as an per-task attribute Parth Shah
2019-12-03 8:36 ` Qais Yousef
2019-12-03 15:47 ` Parth Shah
2019-12-05 9:24 ` Dietmar Eggemann
2019-12-05 11:42 ` Parth Shah
2019-11-25 9:46 ` [RFC 2/3] Propagate parent task's latency requirements to the child task Parth Shah
2019-11-25 9:46 ` [RFC 3/3] Allow sched_{get,set}attr to change latency_tolerance of the task Parth Shah
2019-12-03 8:39 ` Qais Yousef
2019-12-03 15:51 ` Parth Shah
2019-12-05 9:24 ` Dietmar Eggemann
2019-12-06 16:04 ` Dietmar Eggemann
2019-12-08 5:52 ` Parth Shah
2019-12-05 9:24 ` [RFC 0/3] Introduce per-task latency_tolerance for scheduler hints Dietmar Eggemann
2019-12-05 10:49 ` Valentin Schneider
2019-12-05 14:03 ` Dietmar Eggemann [this message]
2019-12-05 17:13 ` Parth Shah
2019-12-06 12:31 ` Dietmar Eggemann
2019-12-08 5:57 ` Parth Shah
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