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From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Ming Lei <ming.lei@redhat.com>,
	Dou Liyang <douly.fnst@cn.fujitsu.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Jens Axboe <axboe@kernel.dk>,
	Christoph Hellwig <hch@infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	linux-block@vger.kernel.org,
	Laurence Oberman <loberman@redhat.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>
Subject: Re: [PATCH V3 0/4] genirq/affinity: irq vector spread among online CPUs as far as possible
Date: Tue, 13 Mar 2018 10:35:30 +0100	[thread overview]
Message-ID: <CAJZ5v0gcmkKVcgDBdt-aePgU0zvQwyf1yX5Qi_zRc1JfzaA5fg@mail.gmail.com> (raw)
In-Reply-To: <1520930375.20980.213.camel@gmail.com>

On Tue, Mar 13, 2018 at 9:39 AM, Artem Bityutskiy <dedekind1@gmail.com> wrote:
> On Tue, 2018-03-13 at 16:35 +0800, Ming Lei wrote:
>> Then looks this issue need to fix by making possible CPU count
>> accurate
>> because there are other resources allocated according to
>> num_possible_cpus(),
>> such as percpu variables.
>
> Short term the regression should be fixed. It is already v4.16-rc6, we
> have little time left.

Right.

> Longer term, yeah, I agree. Kernel's notion of possible CPU count
> should be realistic.

I agree.

Moreover, there are not too many systems where physical CPU hotplug
actually works in practice AFAICS, so IMO we should default to "no
physical CPU hotplug" and only change that default in special cases
(which may be hard to figure out, but that's a different matter).

What platform firmware tells us may be completely off.

  reply	other threads:[~2018-03-13  9:35 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-08 10:53 [PATCH V3 0/4] genirq/affinity: irq vector spread among online CPUs as far as possible Ming Lei
2018-03-08 10:53 ` [PATCH V3 1/4] genirq/affinity: rename *node_to_possible_cpumask as *node_to_cpumask Ming Lei
2018-04-06 21:52   ` [tip:irq/core] genirq/affinity: Rename " tip-bot for Ming Lei
2018-03-08 10:53 ` [PATCH V3 2/4] genirq/affinity: move actual irq vector spread into one helper Ming Lei
2018-04-06 21:53   ` [tip:irq/core] genirq/affinity: Move actual irq vector spreading into a helper function tip-bot for Ming Lei
2018-03-08 10:53 ` [PATCH V3 3/4] genirq/affinity: support to do irq vectors spread starting from any vector Ming Lei
2018-04-06 21:53   ` [tip:irq/core] genirq/affinity: Allow irq spreading from a given starting point tip-bot for Ming Lei
2018-03-08 10:53 ` [PATCH V3 4/4] genirq/affinity: irq vector spread among online CPUs as far as possible Ming Lei
2018-04-03 13:32   ` Thomas Gleixner
2018-04-03 16:00     ` Ming Lei
2018-04-04  8:25       ` Thomas Gleixner
2018-04-04 12:45         ` Thomas Gleixner
2018-04-04 15:20           ` Ming Lei
2018-04-05 10:12             ` Thomas Gleixner
2018-04-04 15:08         ` Ming Lei
2018-04-04 19:38           ` Thomas Gleixner
2018-04-06  9:13             ` Ming Lei
2018-04-06  9:46               ` Thomas Gleixner
2018-04-06 21:49                 ` Thomas Gleixner
2018-04-08  3:19                   ` Ming Lei
2018-04-06 21:54   ` [tip:irq/core] genirq/affinity: Spread irq vectors among present " tip-bot for Ming Lei
2018-03-08 13:18 ` [PATCH V3 0/4] genirq/affinity: irq vector spread among online " Artem Bityutskiy
2018-03-08 13:25   ` Artem Bityutskiy
2018-03-08 13:34   ` Ming Lei
2018-03-08 23:20     ` Thomas Gleixner
2018-03-09  1:24       ` Ming Lei
2018-03-09  7:00         ` Artem Bityutskiy
2018-03-09  7:33           ` Ming Lei
2018-03-09 10:08         ` Thomas Gleixner
2018-03-09 12:08           ` Ming Lei
2018-03-09 15:08             ` Thomas Gleixner
2018-03-13  3:11               ` Dou Liyang
2018-03-13  7:38                 ` Artem Bityutskiy
2018-03-13  8:35                   ` Ming Lei
2018-03-13  8:39                     ` Artem Bityutskiy
2018-03-13  9:35                       ` Rafael J. Wysocki [this message]
2018-03-14  3:29                         ` Dou Liyang
2018-03-14  4:11                           ` Dou Liyang
2018-03-14  9:07                             ` Artem Bityutskiy
2018-03-14  9:47                               ` Dou Liyang
2018-03-13  9:25                 ` Rafael J. Wysocki
2018-03-14  3:30                   ` Dou Liyang
2018-03-30  3:15               ` Ming Lei
2018-04-03 12:55                 ` Thomas Gleixner
2018-03-26  8:39   ` Thorsten Leemhuis
2018-03-28  6:15     ` Artem Bityutskiy

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