From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752842AbcCKNR1 (ORCPT ); Fri, 11 Mar 2016 08:17:27 -0500 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:37846 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752340AbcCKNRU (ORCPT ); Fri, 11 Mar 2016 08:17:20 -0500 Date: Fri, 11 Mar 2016 13:15:04 +0000 From: One Thousand Gnomes To: Peter Zijlstra Cc: Juergen Gross , 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, x86@kernel.org Subject: Re: [PATCH 0/6] Support calling functions on dedicated physical cpu Message-ID: <20160311131504.109cb244@lxorguk.ukuu.org.uk> In-Reply-To: <20160311122514.GA6344@twins.programming.kicks-ass.net> References: <1457697574-6710-1-git-send-email-jgross@suse.com> <20160311122514.GA6344@twins.programming.kicks-ass.net> Organization: Intel Corporation X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.29; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 11 Mar 2016 13:25:14 +0100 Peter Zijlstra wrote: > On Fri, Mar 11, 2016 at 12:59:28PM +0100, Juergen Gross wrote: > > Some hardware (e.g. Dell Studio laptops) require special functions to > > be called on physical cpu 0 in order to avoid occasional hangs. When > > running as dom0 under Xen this could be achieved only via special boot > > parameters (vcpu pinning) limiting the hypervisor in it's scheduling > > decisions. > > So instead of telling Dell to get their act together and fix their damn > firmware, we're going to add the most horrid gunk to the kernel? How > does that make sense? It's been normal forever. The convention with a lot of older BIOS crap was always that it should be called on the boot CPU (APM. PnPBIOS etc). It's a stretch pre-EFI to even call it a "bug" Alan