From: Christoph Hellwig <hch@lst.de>
To: Joe Korty <joe.korty@ccur.com>
Cc: Christoph Hellwig <hch@lst.de>,
Keith Busch <keith.busch@intel.com>,
linux-nvme@lists.infradead.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/6] genirq: allow assigning affinity to present but not online CPUs
Date: Sun, 5 Feb 2017 17:40:23 +0100 [thread overview]
Message-ID: <20170205164023.GA9281@lst.de> (raw)
In-Reply-To: <20170204015809.GA16203@zipoli.ccur.kvm>
Hi Joe,
On Fri, Feb 03, 2017 at 08:58:09PM -0500, Joe Korty wrote:
> IIRC, some years ago I ran across a customer system where
> the #cpus_present was twice as big as #cpus_possible.
>
> Hyperthreading was turned off in the BIOS so it was not
> entirely out of line for the extra cpus to be declared
> present, even though none of them would ever be available
> for use.
This sounds like a system we should quirk around instead of optimizing
for it. Unless I totally misunderstand the idea behind cpu_possible
and cpu_present.
WARNING: multiple messages have this Message-ID (diff)
From: hch@lst.de (Christoph Hellwig)
Subject: [PATCH 1/6] genirq: allow assigning affinity to present but not online CPUs
Date: Sun, 5 Feb 2017 17:40:23 +0100 [thread overview]
Message-ID: <20170205164023.GA9281@lst.de> (raw)
In-Reply-To: <20170204015809.GA16203@zipoli.ccur.kvm>
Hi Joe,
On Fri, Feb 03, 2017@08:58:09PM -0500, Joe Korty wrote:
> IIRC, some years ago I ran across a customer system where
> the #cpus_present was twice as big as #cpus_possible.
>
> Hyperthreading was turned off in the BIOS so it was not
> entirely out of line for the extra cpus to be declared
> present, even though none of them would ever be available
> for use.
This sounds like a system we should quirk around instead of optimizing
for it. Unless I totally misunderstand the idea behind cpu_possible
and cpu_present.
next parent reply other threads:[~2017-02-05 16:40 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <t6NbP-2IT-5@gated-at.bofh.it>
[not found] ` <t6NbP-2IT-13@gated-at.bofh.it>
[not found] ` <20170204015809.GA16203@zipoli.ccur.kvm>
2017-02-05 16:40 ` Christoph Hellwig [this message]
2017-02-05 16:40 ` [PATCH 1/6] genirq: allow assigning affinity to present but not online CPUs Christoph Hellwig
2017-02-06 17:03 ` Keith Busch
2017-02-06 17:03 ` Keith Busch
2017-02-06 17:03 ` Christoph Hellwig
2017-02-06 17:03 ` Christoph Hellwig
2017-02-03 14:35 spread MSI(-X) vectors to all possible CPUs Christoph Hellwig
2017-02-03 14:35 ` [PATCH 1/6] genirq: allow assigning affinity to present but not online CPUs Christoph Hellwig
2017-02-03 14:35 ` Christoph Hellwig
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