Received-SPF: pass (google.com: domain of linux-kernel+bounces-96964-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
Precedence: bulk
MIME-Version: 1.0
References: <20240304094831.3639338-1-mingo@kernel.org> <20240304094831.3639338-7-mingo@kernel.org>
 <xhsmhbk7tdkac.mognet@vschneid-thinkpadt14sgen2i.remote.csb>
 <CAKfTPtCNnTVFdf85sRdJxPhdNZxc8qKcnHL3sznjg-KBVn8Bew@mail.gmail.com> <ZerlUU4kAv580rLh@gmail.com>
In-Reply-To: <ZerlUU4kAv580rLh@gmail.com>
From: Vincent Guittot <vincent.guittot@linaro.org>
Date: Fri, 8 Mar 2024 12:57:54 +0100
Message-ID: <CAKfTPtAwh-khpNw-=oku3VU8xR6qVpoL2hrzEF6u1AZ7WQ+3Cw@mail.gmail.com>
Subject: Re: [PATCH 6/9] sched/balancing: Update run_rebalance_domains() comments
To: Ingo Molnar <mingo@kernel.org>
Cc: Valentin Schneider <vschneid@redhat.com>, linux-kernel@vger.kernel.org, 
	Shrikanth Hegde <sshegde@linux.ibm.com>, Peter Zijlstra <peterz@infradead.org>, 
	Dietmar Eggemann <dietmar.eggemann@arm.com>, Linus Torvalds <torvalds@linux-foundation.org>
Content-Type: text/plain; charset="UTF-8"

On Fri, 8 Mar 2024 at 11:15, Ingo Molnar <mingo@kernel.org> wrote:
>
>
> * Vincent Guittot <vincent.guittot@linaro.org> wrote:
>
> > > """
> > > The run_rebalance_domains() softirq handler is triggered via SCHED_SOFTIRQ
> > > from two places:
> > >
> > > - directly from trigger_load_balance() in scheduler_tick(), for periodic
> > >   load balance
> > >
> > > - indirectly from kick_ilb() (invoked down the scheduler_tick() too), which
> > >   issues an SMP cross-call to nohz_csd_func() which will itself raise the
> > >   softirq, for NOHZ idle balancing.
> >
> > I'm not sure that we should provide too many details of the path as
> > this might change in the future. What about the below ?
> >
> >  - directly from the local scheduler_tick() for periodic load balance
> >
> > - indirectly from a remote scheduler_tick() for NOHZ idle balancing
> > through the SMP cross-call nohz_csd_func()
>
> Okay - I updated it to:
>
>   /*
>    * This softirq handler is triggered via SCHED_SOFTIRQ from two places:
>    *
>    * - directly from the local scheduler_tick() for periodic load balancing
>    *
>    * - indirectly from a remote scheduler_tick() for NOHZ idle balancing
>    *   through the SMP cross-call nohz_csd_func()
>    */
>   static __latent_entropy void run_rebalance_domains(struct softirq_action *h)
>
> Does this work with everyone?

yes looks good for me

>
> Thanks,
>
>         Ingo