From: Dave Chiluk <chiluk@canonical.com>
To: paulmck@linux.vnet.ibm.com
Cc: Rafael Tinoco <rafael.tinoco@canonical.com>,
linux-kernel@vger.kernel.org, davem@davemloft.net,
ebiederm@xmission.com,
Christopher Arges <chris.j.arges@canonical.com>,
Jay Vosburgh <jay.vosburgh@canonical.com>
Subject: Re: Possible netns creation and execution performance/scalability regression since v3.8 due to rcu callbacks being offloaded to multiple cpus
Date: Wed, 11 Jun 2014 13:27:07 -0500 [thread overview]
Message-ID: <53989F7B.6000004@canonical.com> (raw)
In-Reply-To: <20140611161857.GC4581@linux.vnet.ibm.com>
On 06/11/2014 11:18 AM, Paul E. McKenney wrote:
> On Wed, Jun 11, 2014 at 10:46:00AM -0500, David Chiluk wrote:
>> Now think about what happens when a gateway goes down, the namespaces
>> need to be migrated, or a new machine needs to be brought up to replace
>> it. When we're talking about 3000 namespaces, the amount of time it
>> takes simply to recreate the namespaces becomes very significant.
>>
>> The script is a stripped down example of what exactly is being done on
>> the neutron gateway in order to create namespaces.
>
> Are the namespaces torn down and recreated one at a time, or is there some
> syscall, ioctl(), or whatever that allows bulk tear down and recreating?
>
> Thanx, Paul
In the normal running case, the namespaces are created one at a time, as
new customers create a new set of VMs on the cloud.
However, in the case of failover to a new neutron gateway the namespaces
are created all at once using the ip command (more or less serially).
As far as I know there is no syscall or ioctl that allows bulk tear down
and recreation. if such a beast exists that might be helpful.
next prev parent reply other threads:[~2014-06-11 18:27 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-11 5:52 Possible netns creation and execution performance/scalability regression since v3.8 due to rcu callbacks being offloaded to multiple cpus Rafael Tinoco
2014-06-11 7:07 ` Eric W. Biederman
2014-06-11 13:39 ` Paul E. McKenney
2014-06-11 15:17 ` Rafael Tinoco
2014-06-11 15:46 ` David Chiluk
2014-06-11 16:18 ` Paul E. McKenney
2014-06-11 18:27 ` Dave Chiluk [this message]
2014-06-11 19:48 ` Paul E. McKenney
2014-06-11 20:55 ` Eric W. Biederman
2014-06-11 21:03 ` Rafael Tinoco
2014-06-11 20:46 ` Eric W. Biederman
2014-06-11 21:14 ` Dave Chiluk
2014-06-11 22:52 ` Paul E. McKenney
2014-06-11 23:12 ` Eric W. Biederman
2014-06-11 23:49 ` Paul E. McKenney
2014-06-12 0:14 ` Eric W. Biederman
2014-06-12 0:25 ` Rafael Tinoco
2014-06-12 1:09 ` Eric W. Biederman
2014-06-12 1:14 ` Rafael Tinoco
[not found] ` <CAJE_dJzjcWP=e_CPM1M64URVHiEFFb+fP6g2YKZVdoFntkQMZg@mail.gmail.com>
2014-06-13 18:22 ` Rafael Tinoco
2014-06-14 0:02 ` Eric W. Biederman
2014-06-16 15:01 ` Rafael Tinoco
2014-07-17 12:05 ` Rafael David Tinoco
2014-07-24 7:01 ` Eric W. Biederman
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