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
WARNING: multiple messages have this Message-ID (diff)
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: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-10 14:11 [PATCH V2] cpuset: Add knob to make allowed masks hotplug invariant on legacy hierarchy Preeti U Murthy
2015-04-10 14:11 ` Preeti U Murthy
[not found] ` <20150410141118.11284.36206.stgit-KrPcdFQQmm2yUtPGxGje5AC/G2K4zDHf@public.gmane.org>
2015-04-11 8:35 ` Peter Zijlstra
2015-04-11 8:35 ` Peter Zijlstra
2015-04-11 11:21 ` Preeti U Murthy
[not found] ` <552903BC.3050103-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2015-04-11 13:42 ` Peter Zijlstra
2015-04-11 13:42 ` Peter Zijlstra
[not found] ` <20150411083537.GR27490-IIpfhp3q70z/8w/KjCw3T+5/BudmfyzbbVWyRVo5IupeoWH0uzbU5w@public.gmane.org>
2015-04-13 7:01 ` Peter Zijlstra
2015-04-13 7:01 ` Peter Zijlstra
2015-04-13 8:25 ` Preeti U Murthy
[not found] ` <20150413070117.GX24151-ndre7Fmf5hadTX5a5knrm8zTDFooKrT+cvkQGrU6aU0@public.gmane.org>
2015-04-13 12:16 ` Preeti U Murthy
2015-04-13 12:16 ` Preeti U Murthy
[not found] ` <552BB3A5.9060905-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2015-04-13 14:43 ` Peter Zijlstra
2015-04-13 14:43 ` Peter Zijlstra
[not found] ` <20150413144311.GF5029-ndre7Fmf5hadTX5a5knrm8zTDFooKrT+cvkQGrU6aU0@public.gmane.org>
2015-04-15 11:40 ` Preeti U Murthy
2015-04-15 11:40 ` Preeti U Murthy
[not found] ` <552E4E41.3030008-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2015-04-15 15:03 ` Serge E. Hallyn
2015-04-15 15:03 ` Serge E. Hallyn
[not found] ` <20150415150302.GA25089-7LNsyQBKDXoIagZqoN9o3w@public.gmane.org>
2015-04-15 15:19 ` Peter Zijlstra
2015-04-15 15:19 ` Peter Zijlstra
[not found] ` <20150415151926.GS23123-ndre7Fmf5hadTX5a5knrm8zTDFooKrT+cvkQGrU6aU0@public.gmane.org>
2015-04-15 15:30 ` Serge E. Hallyn
2015-04-15 15:30 ` Serge E. Hallyn
[not found] ` <20150415153035.GA25390-7LNsyQBKDXoIagZqoN9o3w@public.gmane.org>
2015-04-15 15:48 ` Tejun Heo
2015-04-15 15:48 ` Tejun Heo
[not found] ` <20150415154802.GB30337-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org>
2015-04-15 16:15 ` Serge E. Hallyn
2015-04-15 16:15 ` Serge E. Hallyn
[not found] ` <20150415161534.GA25776-7LNsyQBKDXoIagZqoN9o3w@public.gmane.org>
2015-04-15 16:18 ` Tejun Heo
2015-04-15 16:18 ` Tejun Heo
2015-04-15 16:36 ` Serge E. Hallyn [this message]
2015-04-15 16:36 ` Serge E. Hallyn
2015-04-16 11:57 ` Preeti U Murthy
[not found] ` <552FA3B4.6080905-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
2015-04-20 3:28 ` Zefan Li
2015-04-20 3:28 ` Zefan Li
2015-04-13 14:50 ` Tejun Heo
2015-04-13 14:50 ` Tejun Heo
2015-04-13 15:05 ` Peter Zijlstra
[not found] ` <20150413145052.GC2596-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org>
2015-04-15 11:12 ` Preeti U Murthy
2015-04-15 11:12 ` Preeti U Murthy
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20150415163617.GA26177@mail.hallyn.com \
--to=serge@hallyn.com \
--cc=anton@samba.org \
--cc=bharata@linux.vnet.ibm.com \
--cc=cgroups@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=lizefan@huawei.com \
--cc=mingo@kernel.org \
--cc=nacc@linux.vnet.ibm.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=preeti@linux.vnet.ibm.com \
--cc=rjw@rjwysocki.net \
--cc=svaidy@linux.vnet.ibm.com \
--cc=tj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.