From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753292AbcDAJ0a (ORCPT ); Fri, 1 Apr 2016 05:26:30 -0400 Received: from mx2.suse.de ([195.135.220.15]:42180 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751432AbcDAJ03 (ORCPT ); Fri, 1 Apr 2016 05:26:29 -0400 Subject: Re: [PATCH v3 5/6] virt, sched: add cpu pinning to smp_call_sync_on_phys_cpu() To: Peter Zijlstra References: <1459494874-12194-1-git-send-email-jgross@suse.com> <1459494874-12194-6-git-send-email-jgross@suse.com> <20160401074325.GC12845@twins.programming.kicks-ass.net> <56FE313E.9060804@suse.com> <20160401084408.GF3448@twins.programming.kicks-ass.net> <56FE3959.2030508@suse.com> <20160401091507.GG3448@twins.programming.kicks-ass.net> Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, konrad.wilk@oracle.com, boris.ostrovsky@oracle.com, david.vrabel@citrix.com, mingo@redhat.com, Douglas_Warzecha@dell.com, pali.rohar@gmail.com, jdelvare@suse.com, linux@roeck-us.net, tglx@linutronix.de, hpa@zytor.com, jeremy@goop.org, chrisw@sous-sol.org, akataria@vmware.com, rusty@rustcorp.com.au, virtualization@lists.linux-foundation.org, x86@kernel.org From: Juergen Gross Message-ID: <56FE3EC1.7000800@suse.com> Date: Fri, 1 Apr 2016 11:26:25 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.0 MIME-Version: 1.0 In-Reply-To: <20160401091507.GG3448@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/04/16 11:15, Peter Zijlstra wrote: > On Fri, Apr 01, 2016 at 11:03:21AM +0200, Juergen Gross wrote: >>> Maybe just make the vpin thing an option like: >>> >>> smp_call_on_cpu(int (*func)(void *), int phys_cpu); > >>> Also; is something like the vpin thing possible on KVM? because if we're >>> going to expose it to generic code like this we had maybe look at wider >>> support. >> >> It is necessary for dom0 under Xen. I don't think there is a need to do >> this on KVM as a guest has no direct access to e.g. BIOS functions of >> the real hardware and the host system needs no vcpu pinning. I'm not >> sure about VMWare. > > OK, then can we WARN if .phys=1 and the platform doesn't support it? > Yes, good idea. Juergen