From: Andi Kleen Subject: Re: [RFC][PATCH 0/5] preempt_count rework Date: Wed, 14 Aug 2013 10:12:16 -0700 Message-ID: <20130814171216.GP23412@tassilo.jf.intel.com> References: <20130814131539.790947874@chello.nl> <20130814164827.GN23412@tassilo.jf.intel.com> <20130814165505.GB21191@laptop.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mga11.intel.com ([192.55.52.93]:3316 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759356Ab3HNRMV (ORCPT ); Wed, 14 Aug 2013 13:12:21 -0400 Content-Disposition: inline In-Reply-To: <20130814165505.GB21191@laptop.programming.kicks-ass.net> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Peter Zijlstra Cc: Linus Torvalds , Ingo Molnar , Peter Anvin , Mike Galbraith , Thomas Gleixner , Arjan van de Ven , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org On Wed, Aug 14, 2013 at 06:55:05PM +0200, Peter Zijlstra wrote: > On Wed, Aug 14, 2013 at 09:48:27AM -0700, Andi Kleen wrote: > > > FWIW I removed the user_schedule in v2 because I don't need it anymore. > > Feel free to pick it up from v1 though. > > Ah, I had a quick look through your v2 because I got a link into it from > Ingo but didn't find it. I'll have to ask Google to locate this v1. I Sorry, it's the thread starting with http://permalink.gmane.org/gmane.linux.kernel/1541950 I also pushed the branch to git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-misc.git uaccess-opt311 is v1 uaccess-opt311-2 is v2 (without user_schedule) > suppose that's what's wrong with my last patch. It directly does a call > preempt_schedule -- which I had hoped would work due to its asmlinkage, > but apparently there's more to it. preempt_schedule does not preserve registers, so yes that would explain a lot of problems. -Andi -- ak@linux.intel.com -- Speaking for myself only