From: David L Stevens <david.stevens@oracle•com>
To: Raghuram Kothakota <Raghuram.Kothakota@oracle•com>
Cc: David Miller <davem@davemloft•net>, netdev@vger•kernel.org
Subject: Re: [PATCHv6 net-next 1/3] sunvnet: upgrade to VIO protocol version 1.6
Date: Mon, 22 Sep 2014 00:40:27 -0400 [thread overview]
Message-ID: <541FA83B.2050608@oracle.com> (raw)
In-Reply-To: <541B395D.1000809@oracle.com>
> On 09/18/2014 02:49 PM, Raghuram Kothakota wrote:
>> In the virtualization world, we want resources to be efficiently used and memory is
>> still very important resource. My concern is mostly because this memory usage of
>> 32+MB is on a per LDC basis. LDoms today supports a max of 128 domains, but
>> from my experience seen actual deployments of the order of 50 domains. This is
>> going up as the platforms getting more and more powerful. If there are really
>> that many peers, then the amount of memory consumed by one vnet instance
>> is 50 * 32+MB = 1.6GB+. It's fine if this memory is really used, but it seems like this
>> will be useful only when the peer is another linux guest with this version of vnet and
>> also the MTU is configured to use 64K. The memory is being wasted for all other
>> peers that either don't support 64K MTU or not configured to use it and also
>> the switch port as obviously it doesn't support 64K MTU today.
I think I have a solution for this -- I'm doing some experimenting, but it may be a few days.
However, fundamentally, the problem is that there are n^2-n links both ways, so 50 LDOMs on the same vswitch
will always be 2450X the resources of a single pair, and lead to scary aggregate numbers. Large installations
really need more vswitches with fewer LDOMs per switch, at least with the current code.
+-DLS
next prev parent reply other threads:[~2014-09-22 4:40 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-18 0:11 [PATCHv6 net-next 1/3] sunvnet: upgrade to VIO protocol version 1.6 David L Stevens
2014-09-18 4:09 ` Raghuram Kothakota
2014-09-18 13:03 ` David L Stevens
2014-09-18 18:49 ` Raghuram Kothakota
2014-09-18 19:58 ` David L Stevens
2014-09-22 4:40 ` David L Stevens [this message]
2014-09-22 16:40 ` Raghuram Kothakota
2014-09-23 16:24 ` David Miller
2014-09-23 16:49 ` David L Stevens
2014-09-23 18:44 ` David Miller
2014-09-24 14:43 ` David L Stevens
2014-09-18 4:23 ` Raghuram Kothakota
2014-09-18 13:21 ` David L Stevens
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