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From: Frederic Weisbecker <frederic@kernel.org>
To: Joel Fernandes <joel@joelfernandes.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>,
	Z qiang <qiang.zhang1211@gmail.com>,
	linux-kernel@vger.kernel.org, rcu@vger.kernel.org
Subject: Re: [PATCH] rcutorture: Traverse possible cpu to set maxcpu in rcu_nocb_toggle()
Date: Tue, 29 Aug 2023 11:24:24 +0200	[thread overview]
Message-ID: <ZO25SDat3cd6opQ7@lothringen> (raw)
In-Reply-To: <16F11103-75C4-4DCE-8272-D619ECAA96BD@joelfernandes.org>

On Mon, Aug 28, 2023 at 05:51:09PM -0400, Joel Fernandes wrote:
> I think the issue is the loop later in the function does
> not try to toggle cpus that came online too late.
> 
> So it does not test offloading on all CPUs just because max got updated too
> late.

Right, and therefore for_each_possible_cpu() or for_each_present_cpu()
should be fine to iterate since it's ok to try to toggle an offline CPU.

> 
> One fix could be to periodically check in the loop if a new cpu at maxcpu + 1
> ever got onlined. If it did, update the maxcpu.

Is it worth the complication though?

Thanks.

> 
> Thanks.
> 
> 
> > 
> > Thanks.

  reply	other threads:[~2023-08-29  9:25 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-24  8:42 [PATCH] rcutorture: Traverse possible cpu to set maxcpu in rcu_nocb_toggle() Zqiang
2023-08-24  8:59 ` Z qiang
2023-08-24 13:21 ` Paul E. McKenney
2023-08-25  2:28   ` Z qiang
2023-08-26  1:29     ` Paul E. McKenney
2023-08-26  6:13       ` Z qiang
2023-08-26 13:06         ` Paul E. McKenney
2023-08-28 15:17           ` Frederic Weisbecker
2023-08-28 21:51             ` Joel Fernandes
2023-08-29  9:24               ` Frederic Weisbecker [this message]
2023-08-29 10:12                 ` Joel Fernandes
2023-08-29 12:38                 ` Paul E. McKenney
2023-09-01 14:56                   ` Paul E. McKenney
  -- strict thread matches above, loose matches on Subject: below --
2023-08-24  8:41 Zqiang

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