Path: csiph.com!news.mixmin.net!weretis.net!feeder4.news.weretis.net!storethat.news.telefonica.de!telefonica.de!news.panservice.it!bofh.it!news.nic.it!robomod From: Peter Zijlstra Newsgroups: linux.kernel Subject: Re: [PATCH 0/6] Support calling functions on dedicated physical cpu Date: Fri, 11 Mar 2016 14:20:02 +0100 Message-ID: References: X-Original-To: One Thousand Gnomes MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2012-12-30) Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 22 Organization: linux.* mail to news gateway X-Original-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 X-Original-Date: Fri, 11 Mar 2016 14:19:17 +0100 X-Original-Message-ID: <20160311131917.GD6344@twins.programming.kicks-ass.net> X-Original-References: <1457697574-6710-1-git-send-email-jgross@suse.com> <20160311122514.GA6344@twins.programming.kicks-ass.net> <20160311131504.109cb244@lxorguk.ukuu.org.uk> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1355900 On Fri, Mar 11, 2016 at 01:15:04PM +0000, One Thousand Gnomes wrote: > 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" Yeah, I knew about the APM/PnP muck, but I was under the impression this was about new hardware.