From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Mason Subject: Re: jumbo frames Date: Wed, 11 May 2005 13:55:13 -0500 Message-ID: <200505111355.13664.jdmason@us.ibm.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com Cc: Kip Macy List-Id: xen-devel@lists.xenproject.org On Wednesday 11 May 2005 01:21 am, Keir Fraser wrote: > On 11 May 2005, at 01:14, Kip Macy wrote: > > What is the status of jumbo frame support in dom0 and domU? Unless > > something has changed I know it isn't supported in domU, but shouldn't > > it just work in dom0? > > I think it'll just work, but it's untested. If the jumbo area spans > multiple memory pages then it needs to be allocated with something like > dma_alloc_coherent, or be represented by a fragmented skbuff. (i.e., > hopefully the network stack and drivers don't assume that kmalloc() > always return physically contiguous memory extents). I've actually wanted to look into this for a while. It seems to me that MTUs of ~4000 (1 page) should be fairly trivial to impliment, and should boost performance significantly (with no extra cost as we are using the full page anyway). Kip, if you don't want to do it, I will ;-) Thanks, Jon