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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 6A07DC33CA2 for ; Fri, 10 Jan 2020 11:44:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4689D2080D for ; Fri, 10 Jan 2020 11:44:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727887AbgAJLox (ORCPT ); Fri, 10 Jan 2020 06:44:53 -0500 Received: from foss.arm.com ([217.140.110.172]:42924 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727457AbgAJLox (ORCPT ); Fri, 10 Jan 2020 06:44:53 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 352771063; Fri, 10 Jan 2020 03:44:52 -0800 (PST) Received: from [10.37.13.8] (unknown [10.37.13.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A1DBA3F534; Fri, 10 Jan 2020 03:44:46 -0800 (PST) Subject: Re: [PATCHv8 02/34] lib/vdso: make do_hres and do_coarse as __always_inline To: Thomas Gleixner , Dmitry Safonov , linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Andrei Vagin , Adrian Reber , Andrei Vagin , Andy Lutomirski , Arnd Bergmann , Christian Brauner , Cyrill Gorcunov , "Eric W. Biederman" , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Jeff Dike , Oleg Nesterov , Pavel Emelyanov , Shuah Khan , containers@lists.linux-foundation.org, criu@openvz.org, linux-api@vger.kernel.org, x86@kernel.org References: <20191112012724.250792-1-dima@arista.com> <20191112012724.250792-3-dima@arista.com> <878smfa66i.fsf@nanos.tec.linutronix.de> From: Vincenzo Frascino Message-ID: Date: Fri, 10 Jan 2020 11:47:43 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <878smfa66i.fsf@nanos.tec.linutronix.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/10/20 11:42 AM, Thomas Gleixner wrote: > Vincenzo Frascino writes: >> On 11/12/19 1:26 AM, Dmitry Safonov wrote: >>> +» » vd·=·&vd[CS_HRES_COARSE]; >>> +out_hres: >>> +» » return·do_hres(vd,·clock,·ts); >>> » }·else·if·(msk·&·VDSO_COARSE)·{ >>> » » do_coarse(&vd[CS_HRES_COARSE],·clock,·ts); >>> » » return·0; >>> » }·else·if·(msk·&·VDSO_RAW)·{ >>> -» » return·do_hres(&vd[CS_RAW],·clock,·ts); >>> +» » vd·=·&vd[CS_RAW]; >>> +» » /*·goto·allows·to·avoid·extra·inlining·of·do_hres.·*/ >>> +» » goto·out_hres; >> >> What is the performance impact of "goto out_hres"? > > On x86 it's invisible at least in my limited testing. On arm64 as well based on mine as well. Shall we keep the code more readable here (without goto)? > > Thanks, > > tglx > -- Regards, Vincenzo