From: "Serge E. Hallyn" <serge@hallyn.com>
To: Tejun Heo <tj@kernel.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>,
Peter Zijlstra <peterz@infradead.org>,
Preeti U Murthy <preeti@linux.vnet.ibm.com>,
svaidy@linux.vnet.ibm.com, nacc@linux.vnet.ibm.com,
rjw@rjwysocki.net, linux-kernel@vger.kernel.org,
lizefan@huawei.com, anton@samba.org, bharata@linux.vnet.ibm.com,
cgroups@vger.kernel.org, paulmck@linux.vnet.ibm.com,
mingo@kernel.org
Subject: Re: [PATCH V2] cpuset: Add knob to make allowed masks hotplug invariant on legacy hierarchy
Date: Wed, 15 Apr 2015 11:36:17 -0500 [thread overview]
Message-ID: <20150415163617.GA26177@mail.hallyn.com> (raw)
In-Reply-To: <20150415161811.GD30337@htj.duckdns.org>
On Wed, Apr 15, 2015 at 12:18:11PM -0400, Tejun Heo wrote:
> On Wed, Apr 15, 2015 at 11:15:35AM -0500, Serge E. Hallyn wrote:
> > The reason would be because it breaks "legacy" software. So that
> > would only matter if Preeti needs to run such software.
>
> Sure, I get that argument but this is changing how the contorller
> behaves in a major way.
It is. My main counter to that would be that it is how cpusets
should always have worked :)
> There are specifics which may make this
> particular case more justifiable but overall the combination of
> arguments is pretty weird.
And becomes harder to reason about and review/maintain. I agree
there.
>From userspace, I suppose one approach (though note it is racy) to
solving this would be to have udev rules which
. On cpu unplug, record all cgroups which were using that cpu
. on cpu plug, re-add the cpu to all recorded cgroups for that
cpu (if any), as well as to any cgroups marked (in some /etc
file) as using "all" or a percentage of all cpus.
-serge
next prev parent reply other threads:[~2015-04-15 16:36 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-10 14:11 Preeti U Murthy
2015-04-11 8:35 ` Peter Zijlstra
2015-04-11 11:21 ` Preeti U Murthy
2015-04-11 13:42 ` Peter Zijlstra
2015-04-13 7:01 ` Peter Zijlstra
2015-04-13 8:25 ` Preeti U Murthy
2015-04-13 12:16 ` Preeti U Murthy
2015-04-13 14:43 ` Peter Zijlstra
2015-04-15 11:40 ` Preeti U Murthy
2015-04-15 15:03 ` Serge E. Hallyn
2015-04-15 15:19 ` Peter Zijlstra
2015-04-15 15:30 ` Serge E. Hallyn
2015-04-15 15:48 ` Tejun Heo
2015-04-15 16:15 ` Serge E. Hallyn
2015-04-15 16:18 ` Tejun Heo
2015-04-15 16:36 ` Serge E. Hallyn [this message]
2015-04-16 11:57 ` Preeti U Murthy
2015-04-20 3:28 ` Zefan Li
2015-04-13 14:50 ` Tejun Heo
2015-04-13 15:05 ` Peter Zijlstra
2015-04-15 11:12 ` Preeti U Murthy
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