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Date: Fri, 11 Sep 2015 22:35:47 +0530
Message-ID: <CAHjTdYd=MmgRcRPsMjJ58bNtcPiqywDfj=z-5zD+sD7GGVwVGA@mail.gmail.com>
Subject: Re: [PATCH 0/2] nohz_full: Offload task_tick to remote housekeeping
 cpus for nohz_full cpus
From: Vatika Harlalka <vatikaharlalka@gmail.com>
To: Preeti Murthy <preeti.murthy@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>, preetium@andrew.cmu.edu,
        Peter Zijlstra <peterz@infradead.org>, mingo@redhat.com,
        Thomas Gleixner <tglx@linutronix.de>, rafael.j.wysocki@intel.com,
        schwidefsky@de.ibm.com, linux-kernel <linux-kernel@vger.kernel.org>
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> 1. If LB_BIAS is false for nohz_full CPUs. This will help us figure out if
> rq->cpu_load
> is read for them.

lb_bias feature is not disabled for full dynticks. rq->cpu_load[] is
never used for them.
nohz_full cpus verify the condition on_null_domain(rq)

> 2. When a cpu reports scheduling stats for all cpus such as
> sum_exec_runtime,
> does it consider cpu_isolated_map (most likely it will) ? If it does, we
> need to be
> able to remotely update those statistics before reporting them. i.e. call
> update_curr(rq) on behalf of the nohz_full cpus.

Yeah, cpu stats are reported and updated for all cpus.

The next step would be to offload these on other cpus now for nohz_full cpus
running a single task now?

Thanks
Vatika

>
>
>
> --
> This is Preeti, signing off.