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Date:   Sat, 4 Apr 2020 23:05:52 +0000 (UTC)
From:   Christopher Lameter <cl@linux.com>
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To:     Peter Zijlstra <peterz@infradead.org>
cc:     Marcelo Tosatti <mtosatti@redhat.com>,
        linux-kernel@vger.kernel.org,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Chris Friesen <chris.friesen@windriver.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        Jim Somerville <Jim.Somerville@windriver.com>
Subject: Re: [patch 3/3] isolcpus: undeprecate on documentation
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On Tue, 31 Mar 2020, Peter Zijlstra wrote:

> > Why do you dislike it? What you think would be a decent approach?
>
> Try and reconfigure it after boot.

Not really a problem since this is not the only issue that requires a
reboot.

You have to reboot most of the time if you change applications on a HPC
machine. After all you cannot reliably change the available set of huge
pages after boot. So you have to reboot anyways if you want some cores to
do different things.

And then the machines performance goes down over time due to
memory fragmentation. So you better reboot frequently.

Thus reboot, reboot, reboot. We have become like Windows 95 ...