From: Michal Hocko <mhocko@suse.com>
To: Frederic Weisbecker <frederic@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Kees Cook <kees@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Vlastimil Babka <vbabka@suse.cz>,
linux-mm@kvack.org, "Paul E. McKenney" <paulmck@kernel.org>,
Neeraj Upadhyay <neeraj.upadhyay@kernel.org>,
Joel Fernandes <joel@joelfernandes.org>,
Boqun Feng <boqun.feng@gmail.com>,
Zqiang <qiang.zhang1211@gmail.com>,
rcu@vger.kernel.org
Subject: Re: [PATCH 12/19] kthread: Default affine kthread to its preferred NUMA node
Date: Wed, 18 Sep 2024 13:17:09 +0200 [thread overview]
Message-ID: <Zuq2tVC8GlBJwUJ7@tiehlicka> (raw)
In-Reply-To: <ZuqfZhvWB5ox4nh3@localhost.localdomain>
On Wed 18-09-24 11:37:42, Frederic Weisbecker wrote:
> Le Tue, Sep 17, 2024 at 01:07:25PM +0200, Michal Hocko a écrit :
[...]
> > I am not objecting to patch per se. I am just not sure this is really
> > needed. It is great to have kernel threads bound to non isolated cpus by
> > default if they have node preferences. But as soon as somebody starts
> > offlining cpus excessively and make the initial cpumask empty then
> > select_fallback_rq sounds like the right thing to do.
> >
> > Not my call though. I was just curious why this is needed and it seems
> > to me you are looking for some sort of correctness for broken setups.
>
> It looks like it makes sense to explore that path. We still need the
> cpu up probe to reaffine when a suitable target comes up. But it seems
> the CPU down part can be handled by select_fallback_rq. I'll try that.
THanks! Btw. when you are looking at this, would it make sense to make
select_fallback_rq more cpu isolation aware as well? I mean using
housekeeping cpus before falling back to task_cpu_possible_mask?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2024-09-18 11:17 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20240916224925.20540-1-frederic@kernel.org>
2024-09-16 22:49 ` [PATCH 11/19] kthread: Make sure kthread hasn't started while binding it Frederic Weisbecker
2024-09-16 22:49 ` [PATCH 12/19] kthread: Default affine kthread to its preferred NUMA node Frederic Weisbecker
2024-09-17 6:26 ` Michal Hocko
2024-09-17 7:01 ` Vlastimil Babka
2024-09-17 7:05 ` Michal Hocko
2024-09-17 7:14 ` Vlastimil Babka
2024-09-17 10:34 ` Frederic Weisbecker
2024-09-17 11:07 ` Michal Hocko
2024-09-18 9:37 ` Frederic Weisbecker
2024-09-18 11:17 ` Michal Hocko [this message]
2024-09-16 22:49 ` [PATCH 13/19] mm: Create/affine kcompactd to its preferred node Frederic Weisbecker
2024-09-17 6:04 ` Michal Hocko
2024-09-16 22:49 ` [PATCH 14/19] mm: Create/affine kswapd " Frederic Weisbecker
2024-09-17 6:05 ` Michal Hocko
2024-09-16 22:49 ` [PATCH 15/19] kthread: Implement preferred affinity Frederic Weisbecker
[not found] <20241211154035.75565-1-frederic@kernel.org>
2024-12-11 15:40 ` [PATCH 12/19] kthread: Default affine kthread to its preferred NUMA node Frederic Weisbecker
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