Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751334AbaJAFJZ (ORCPT ); Wed, 1 Oct 2014 01:09:25 -0400 Received: from mail-lb0-f172.google.com ([209.85.217.172]:62783 "EHLO mail-lb0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750925AbaJAFJX (ORCPT ); Wed, 1 Oct 2014 01:09:23 -0400 Message-ID: <542B8C7F.70108@fds-team.de> Date: Wed, 01 Oct 2014 07:09:19 +0200 From: Sebastian Lackner User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.2 MIME-Version: 1.0 To: Andy Lutomirski , Thomas Gleixner , X86 ML , Ingo Molnar , "H. Peter Anvin" CC: Anish Bhatt , "linux-kernel@vger.kernel.org" , Chuck Ebbert , stable@vger.kernel.org Subject: Re: [PATCH v2 1/2] x86_64,entry: Filter RFLAGS.NT on entry from userspace References: <0e906bdeba3660c9766248d3d7229e78a423ca5b.1412138935.git.luto@amacapital.net> In-Reply-To: <0e906bdeba3660c9766248d3d7229e78a423ca5b.1412138935.git.luto@amacapital.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 > + testl $X86_EFLAGS_NT,EFLAGS(%rsp) /* saved EFLAGS match cpu */ > + jz 1f > + pushq_cfi $(X86_EFLAGS_IF|X86_EFLAGS_FIXED) > + popfq_cfi > +1: > + Do you think it makes sense to change the order here, so that no jump happens if NT is not set (which happens a bit more often, than the other way round)? Just a guess though, haven't measured if pipeline effects have such a big influence in this case. ;) -- 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/