Date: Mon, 28 Aug 2017 11:53:46 -0500 (CDT)
From: Christopher Lameter <cl@linux.com>
To: Peter Zijlstra <peterz@infradead.org>
cc: Frederic Weisbecker <fweisbec@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Chris Metcalf <cmetcalf@mellanox.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Luiz Capitulino <lcapitulino@redhat.com>,
        "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
        Ingo Molnar <mingo@kernel.org>, Mike Galbraith <efault@gmx.de>,
        Rik van Riel <riel@redhat.com>, Wanpeng Li <kernellwp@gmail.com>
Subject: Re: [RFC PATCH 12/12] housekeeping: Reimplement isolcpus on
 housekeeping
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On Mon, 28 Aug 2017, Peter Zijlstra wrote:

> Well, ideally something like this would start the system with all the
> 'crap' threads in !root cgroup. But that means cgroupfs needs to be
> populated with at least two directories on boot. And current cgroup
> cruft doesn't expect that.

Maybe an affinity mask for bootup will take care of that? I once wrote an
init wrapper that restricted the number of cpus for the threads that init
spawns but we can probably do much better.