Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758798Ab3HJU1N (ORCPT ); Sat, 10 Aug 2013 16:27:13 -0400 Received: from terminus.zytor.com ([198.137.202.10]:35121 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758779Ab3HJU1M (ORCPT ); Sat, 10 Aug 2013 16:27:12 -0400 Message-ID: <5206A1FD.4020603@zytor.com> Date: Sat, 10 Aug 2013 13:26:37 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Linus Torvalds CC: Mike Galbraith , Andi Kleen , Linux Kernel Mailing List , the arch/x86 maintainers , Ingo Molnar Subject: Re: Re-tune x86 uaccess code for PREEMPT_VOLUNTARY References: <1376089460-5459-1-git-send-email-andi@firstfloor.org> <5205C4BB.6020003@zytor.com> <1376114128.5332.17.camel@marge.simpson.net> <5206659F.9070705@zytor.com> <520675D3.7030703@zytor.com> In-Reply-To: X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 609 Lines: 16 On 08/10/2013 11:51 AM, Linus Torvalds wrote: > That "kernel_stack" thing is actually getting the thread_info pointer, > and it doesn't get cached because gcc thinks the preempt_count value > might alias. This is just plain braindamaged. Somewhere on my list of things is to merge thread_info and task_struct and have a pointer to the unified structure. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/