From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5AE9C282D8 for ; Sat, 2 Feb 2019 02:52:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 93BAA2148D for ; Sat, 2 Feb 2019 02:52:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549075970; bh=kIGqXvcpyLnfAD3MHpZJsKj71GoTka2Lw9lznxRezNo=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=caJ/uiSS+PXHrwyqoQhAgSPELmppUqn/KW+Y84pHUDvPaWKb/883dHVbS8K7xTOQQ 1EcyDJ965L6syCI/j2bdKpHn2kYE2YURZoR8tI4DK9OJE15zH7UK6DkVs06jcAAXWq skYaNRTg10jl8kiZWaSKBAs3Lv/MfQ9Cbbgj40Kc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727505AbfBBCwt (ORCPT ); Fri, 1 Feb 2019 21:52:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:57204 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726506AbfBBCws (ORCPT ); Fri, 1 Feb 2019 21:52:48 -0500 Received: from mail-wr1-f54.google.com (mail-wr1-f54.google.com [209.85.221.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B4021218FF for ; Sat, 2 Feb 2019 02:52:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549075968; bh=kIGqXvcpyLnfAD3MHpZJsKj71GoTka2Lw9lznxRezNo=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=zuCZY4m4IyGnYksmS2iYk/Rlw61CbnTHHWXzuwpKAcnAiFrPnLAyWGSeX/2vCVtI5 L0vVk8AYYqx7AnkHkD/ppeOybItm0b92GSAyGdf46v9RQLJbEW1ulY0krmrxh/uIXJ 1BsMvDypJW8Eh1b00fKbfp8SR3+jKTbGAIQnd9Yc= Received: by mail-wr1-f54.google.com with SMTP id p4so9052666wrt.7 for ; Fri, 01 Feb 2019 18:52:47 -0800 (PST) X-Gm-Message-State: AJcUukfJhAB7OMigCDvbcVd34IyaOu0l8jA9Q5Y5Smyat7jm5xxVE/3q 5IJhlTove3pcrUMWnpEMxtrLMxglNWcJRNct2tK/OA== X-Google-Smtp-Source: ALg8bN41oNfvNsqMUUOE687jCWUyFIF4TzsmU1j9P5CfVvmsUOMljfrsYFC+TPO/PG5kjjoEss2Ktp0vxhQNRX2kw3s= X-Received: by 2002:adf:8323:: with SMTP id 32mr39541754wrd.176.1549075966133; Fri, 01 Feb 2019 18:52:46 -0800 (PST) MIME-Version: 1.0 References: <20190201205319.15995-1-chang.seok.bae@intel.com> <20190201205319.15995-5-chang.seok.bae@intel.com> In-Reply-To: <20190201205319.15995-5-chang.seok.bae@intel.com> From: Andy Lutomirski Date: Fri, 1 Feb 2019 18:52:35 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v5 04/13] x86/fsgsbase/64: Add intrinsics for FSGSBASE instructions To: "Chang S. Bae" Cc: Andy Lutomirski , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Andi Kleen , Markus T Metzger , Ravi Shankar , LKML Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 1, 2019 at 12:54 PM Chang S. Bae wrote: > > From: Andi Kleen > > Add C intrinsics and assembler macros for the new FSBASE and GSBASE > instructions. > > Very straight forward. Used in followon patches. > > [ luto: Rename the variables from FS and GS to FSBASE and GSBASE and > make safe to include on 32-bit kernels. ] > > v2: Use __always_inline > > [ chang: Revise the changelog. Place them in . Replace > the macros with GAS-compatible ones. ] > > If GCC supports it, we can add -mfsgsbase to CFLAGS and use the builtins > here for extra performance Does it really get better performance? If so, let's do it. If not, let's remove the comment. And, whatever you do, please put this above the [luto] and [chang] parts. . > > [ chang: Use FSGSBASE instructions directly. Removed GAS-compatible > macros as the minimum required binutils (v2.21) supports the FSGSBASE > instructions. ] Can you stick the "v2" revision notes below the --- or even just remove them? It makes the changelog a lot harder to review and it's not really useful in the git tree.