From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Liu Subject: Re: [RFC PATCH V2] New Xen netback implementation Date: Sun, 29 Jan 2012 13:42:41 +0000 Message-ID: <1327844561.2911.5.camel@leeds.uk.xensource.com> References: <1326808024-3744-1-git-send-email-wei.liu2@citrix.com> <20120127192214.GA14437@phenom.dumpdata.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: , Ian Campbell , "netdev@vger.kernel.org" , "xen-devel@lists.xensource.com" , "David Vrabel" , Paul Durrant To: Konrad Rzeszutek Wilk Return-path: Received: from smtp.ctxuk.citrix.com ([62.200.22.115]:36142 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753086Ab2A2Nxi (ORCPT ); Sun, 29 Jan 2012 08:53:38 -0500 In-Reply-To: <20120127192214.GA14437@phenom.dumpdata.com> Sender: netdev-owner@vger.kernel.org List-ID: On Fri, 2012-01-27 at 19:22 +0000, Konrad Rzeszutek Wilk wrote: > On Tue, Jan 17, 2012 at 01:46:56PM +0000, Wei Liu wrote: > > A new netback implementation which includes three major features: > > > > - Global page pool support > > - NAPI + kthread 1:1 model > > - Netback internal name changes > > > > Changes in V2: > > - Fix minor bugs in V1 > > - Embed pending_tx_info into page pool > > - Per-cpu scratch space > > - Notification code path clean up > > > > This patch series is the foundation of furture work. So it is better > > to get it right first. Patch 1 and 3 have the real meat. > > I've been playing with these patches and couple of things > came to my mind: > - would it make sense to also register to the shrinker API? This way > if the host is running low on memory it can squeeze it out of the > pool code. Perhaps a future TODO.. > - I like the pool code. I was thinking that perhaps (in the future) > it could be used by blkback as well, as it runs into "not enought > request structure" with the default setting. And making this dynamic > would be pretty sweet. Interesting thoughts worth adding to TODO list. But I'm focusing on multi-page ring support and split event channel at the moment, which should help improve performance on 10G network. Hopefully I can submit RFC patch V3 in a few days. ;-) > - This patch set solves the CPU banding problem I've seen with the > older netback. The older one I could see X netback threads eating 80% > of CPU. With this one, the number is down to 13-14%. > > So you can definitly stick 'Tested-by: Konrad.." on them. And definitly > Reviewed-by on the first two - hadn't had a chance to look at the rest. > Thanks for your extensive test and review. Wei.