From: Peter Zijlstra <peterz@infradead.org>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Daniel Bristot de Oliveira <bristot@redhat.com>,
Valentin Schneider <valentin.schneider@arm.com>,
Ingo Molnar <mingo@kernel.org>,
"Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Subject: Re: [PATCH] notifier: Make atomic_notifiers use raw_spinlock
Date: Fri, 6 Aug 2021 20:20:49 +0200 [thread overview]
Message-ID: <20210806182049.GC2184@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20210806180653.mohdmxgrt6h3valt@linutronix.de>
On Fri, Aug 06, 2021 at 08:06:53PM +0200, Sebastian Andrzej Siewior wrote:
> On 2021-08-06 20:02:42 [+0200], Peter Zijlstra wrote:
> > On Fri, Aug 06, 2021 at 04:07:18PM +0200, Sebastian Andrzej Siewior wrote:
> > > What do we do with this?
> > > Do we merge this as-is, add another "robust atomic notifier" using only
> > > raw_spinlock_t for registration and notification (for only
> > > cpu_pm_notifier_chain) instead of switching to raw_spinlock_t for all
> > > atomic notifier in -tree?
> >
> > Right, so the problem I see with this is that
> > notifier_chain_{,un}register() are O(n). Hardly something we should be
> > putting under raw_spin_lock :/
>
> Yup, pretty much. So we make one robust notifier for
> cpu_pm_notifier_chain?
Yeah, I suppose so :-( Ideally that whole pm notifier thing goes, but
that's *far* more work and I really don't want to be responsible for the
brain damange resulting from looking at all that 'special' idle code.
next prev parent reply other threads:[~2021-08-06 18:21 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-06 14:07 [PATCH] notifier: Make atomic_notifiers use raw_spinlock Sebastian Andrzej Siewior
2021-08-06 18:02 ` Peter Zijlstra
2021-08-06 18:06 ` Sebastian Andrzej Siewior
2021-08-06 18:20 ` Peter Zijlstra [this message]
-- strict thread matches above, loose matches on Subject: below --
2020-11-22 20:19 Valentin Schneider
2020-11-23 14:14 ` Peter Zijlstra
2020-11-23 14:52 ` Valentin Schneider
2020-11-30 10:09 ` Valentin Schneider
2020-11-30 13:51 ` Sebastian Andrzej Siewior
2020-11-30 13:55 ` Daniel Bristot de Oliveira
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