From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: Re: [Xen-devel] [PATCH 1/8] netback: don't bind kthread to cpu Date: Tue, 5 Mar 2013 14:42:26 +0000 Message-ID: <51360452.5070200@citrix.com> References: <1360944010-15336-1-git-send-email-wei.liu2@citrix.com> <1360944010-15336-2-git-send-email-wei.liu2@citrix.com> <20130304205154.GB16762@phenom.dumpdata.com> <1362490210.4748.23.camel@zion.uk.xensource.com> <20130305135649.GA2589@phenom.dumpdata.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Cc: Wei Liu , "netdev@vger.kernel.org" , "annie.li@oracle.com" , Ian Campbell , "xen-devel@lists.xen.org" To: Konrad Rzeszutek Wilk Return-path: Received: from smtp02.citrix.com ([66.165.176.63]:34096 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753705Ab3CEOm3 (ORCPT ); Tue, 5 Mar 2013 09:42:29 -0500 In-Reply-To: <20130305135649.GA2589@phenom.dumpdata.com> Sender: netdev-owner@vger.kernel.org List-ID: On 05/03/13 13:56, Konrad Rzeszutek Wilk wrote: > On Tue, Mar 05, 2013 at 01:30:10PM +0000, Wei Liu wrote: >> On Mon, 2013-03-04 at 20:51 +0000, Konrad Rzeszutek Wilk wrote: >>> On Fri, Feb 15, 2013 at 04:00:02PM +0000, Wei Liu wrote: >>>> The initialization process makes an assumption that the online cpus are >>>> numbered from 0 to xen_netbk_group_nr-1, which is not always true. >>> >>> And xen_netbk_group_nr is num_online_cpus()? >>> >> >> Yes. >> >>> So under what conditions does this change? Is this when the CPU hotplug >>> is involved and the CPUs go offline? In which case should there be a >> >> Yes, the hotplug path. >> >>> CPU hotplug notifier to re-bind the workers are appropiate? > > ? > Can't that option be explored? I'm not sure binding netback threads to particular VCPUs is useful without also binding the events to the corresponding VCPUs. I would hope that the scheduler would tend to the correct behavior if threads aren't bound, anyway. David