Date: Mon, 12 Feb 2007 01:18:43 -0800
From: Paul Jackson <pj@sgi.com>
To: menage@google.com
Cc: akpm@osdl.org, sekharan@us.ibm.com, dev@sw.ru, xemul@sw.ru,
       serue@us.ibm.com, vatsa@in.ibm.com, ebiederm@xmission.com,
       ckrm-tech@lists.sourceforge.net, linux-kernel@vger.kernel.org,
       rohitseth@google.com, mbligh@google.com, winget@google.com,
       containers@lists.osdl.org, devel@openvz.org
Subject: Re: [PATCH 0/7] containers (V7): Generic Process Containers
Message-Id: <20070212011843.c6e8f4ae.pj@sgi.com>
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> - temporarily removed the "release agent" support.

ouch

> ... it can be re-added ... via a kernel thread that periodically polls containers ...

double ouch.

You'll have a rough time selling me on the idea that some kernel thread
should be waking up every few seconds, grabbing system-wide locks, on a
big honkin NUMA box, for the few times per hour, or less, that a cpuset is
abandoned.

Offhand, that sounds mildly insane to me.

And how would this get the edge-triggered, rather than level-triggered,
release?  In other words, if a new cpuset is created, and marked with
the notify_on_release flag, but otherwise not yet used (no child
cpusets and no tasks in it) then it is not to be released (removed.)
Only children and/or tasks are added, then later removed, is it a
candidate for release.  I guess you'll need yet another state bit, set
when the cpuset is abandoned (last child removed or last pid
exits/leaves), and cleared when this kernel thread visits the cpuset to
see if it should be removed.

Can you explain to me how this intruded on the reference counting?

-- 
                  I won't rest till it's the best ...
                  Programmer, Linux Scalability
                  Paul Jackson <pj@sgi.com> 1.925.600.0401
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