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=-0.0 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, FROM_LOCAL_NOVOWEL,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 8F652C4360F for ; Thu, 4 Apr 2019 18:59:06 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 0BBD72075E for ; Thu, 4 Apr 2019 18:59:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="M76lnXAH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0BBD72075E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 44ZsgD0vT9zDqRF for ; Fri, 5 Apr 2019 05:59:04 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::b44; helo=mail-yb1-xb44.google.com; envelope-from=jcmvbkbc@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="M76lnXAH"; dkim-atps=neutral Received: from mail-yb1-xb44.google.com (mail-yb1-xb44.google.com [IPv6:2607:f8b0:4864:20::b44]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 44ZscN1vwnzDqBd for ; Fri, 5 Apr 2019 05:56:36 +1100 (AEDT) Received: by mail-yb1-xb44.google.com with SMTP id b88so1437791ybi.6 for ; Thu, 04 Apr 2019 11:56:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=czb2ENwQGWnSQaCPQIrYNCynYy2KSbTtKbmrxk8aiuA=; b=M76lnXAHZW3E/8sfPEo6AMsEvKo1Fj2EhqlUI6eC714OKjs2ScEs0g5Kdp16SCqkPF N0+X6xTwMiV/VBKBoM8U7lCaiLZf0D5h8H0NYyJsPMWgNRUMOJFoGIeE3Kw2Z03GU9vT zVyDQ6CnNyqqWAbFqnkhKqeqcKWpSWW3q20J6IQ+uvd8srIqBj9yOsnXEon9ojIURp4v bTLlHhqhnN0+9uDyqXd9PWoJbT4ZfrXOkz5CQF3mN7LEVXFyBxCwjgwaWqj7DMqenuLs uXedhWbK9lmCM0WnwBXxlX+/J6awXNP/t6T5RlKFdEob9MOiRhxs9ue2K7i3gYHUzYfA pf5g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=czb2ENwQGWnSQaCPQIrYNCynYy2KSbTtKbmrxk8aiuA=; b=YqcjxKqSeOgoMxWwyVj0heLGpY5PNI+JvoAPMcTeNCzjWkHwU8mdgmCstTNWJ5p52k T6g/HtRskJ0XtMAM8mLBxtVOQF0VuuotEaS9N5VEtu4zYqyaLTWdp+hUvxBp8E1cQCGR aqL2uBcmJFRClh/r2hUHMMYtcS0hPQJMTKba9MHuBMGKeULgQUJBZQWTkJE7h0vYcVMK L5XdwhX4MsXW+YY7BGVB00BI2U48KLDiQ2qPpCQIFc4ttwc6T84U+p+epgQkfsHDGSPe RKveIiMTYjlATUhsES1bjBlmCNlgyiDT9JBSQpYLyzJwAF2OsvXZuor60JBiN/akvqOG ZYAA== X-Gm-Message-State: APjAAAWtzDnSDph6knJm+zYo7B7c5luFaccD60lUiNdhOSAhFIxQyVQd 2gsv+HQpVSWQKtGSjPId2Ry36QglFjEJ9jDhVk7yl5ihO3MS8g== X-Google-Smtp-Source: APXvYqw2AeCdLcNxw3yXyG2q9A1yJJjPzbkEFkUNasjS0SEO0/rC6tigTrt97xSpbl9QpVkQd9PzuPxHxf4nnJWaXhg= X-Received: by 2002:a25:6c88:: with SMTP id h130mr6951040ybc.112.1554404194312; Thu, 04 Apr 2019 11:56:34 -0700 (PDT) MIME-Version: 1.0 References: <20190401134104.676620247@goodmis.org> <20190401134421.278590567@goodmis.org> In-Reply-To: <20190401134421.278590567@goodmis.org> From: Max Filippov Date: Thu, 4 Apr 2019 11:56:23 -0700 Message-ID: Subject: Re: [PATCH 5/6 v3] syscalls: Remove start and number from syscall_get_arguments() args To: Steven Rostedt Content-Type: text/plain; charset="UTF-8" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "open list:IA64 \(Itanium\) PL..." , "Gustavo A. R. Silva" , Peter Zijlstra , Palmer Dabbelt , Dominik Brodowski , Oleg Nesterov , "H. Peter Anvin" , "open list:SPARC + UltraSPAR..." , linux-riscv@lists.infradead.org, Ingo Molnar , Linux-Arch , linux-s390 , linux-c6x-dev@linux-c6x.org, "open list:SUPERH" , "open list:QUALCOMM HEXAGON..." , "maintainer:X86 ARCHITECTURE..." , Ingo Molnar , linux-snps-arc@lists.infradead.org, Dave Martin , "moderated list:H8/300 ARCHITECTURE" , linux-xtensa@linux-xtensa.org, Kees Cook , Roland McGrath , linux-um@lists.infradead.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, Borislav Petkov , Andy Lutomirski , Thomas Gleixner , "Dmitry V. Levin" , linux-arm-kernel@lists.infradead.org, "open list:PARISC ARCHITECTURE" , linuxppc-dev@lists.ozlabs.org, LKML , Andy Lutomirski , "Eric W. Biederman" , nios2-dev@lists.rocketboards.org, Andrew Morton , Linus Torvalds Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Apr 1, 2019 at 6:45 AM Steven Rostedt wrote: > > From: "Steven Rostedt (Red Hat)" > > At Linux Plumbers, Andy Lutomirski approached me and pointed out that the > function call syscall_get_arguments() implemented in x86 was horribly > written and not optimized for the standard case of passing in 0 and 6 for > the starting index and the number of system calls to get. When looking at > all the users of this function, I discovered that all instances pass in only > 0 and 6 for these arguments. Instead of having this function handle > different cases that are never used, simply rewrite it to return the first 6 > arguments of a system call. > > This should help out the performance of tracing system calls by ptrace, > ftrace and perf. [...] > arch/xtensa/include/asm/syscall.h | 16 ++---- For xtensa changes: Acked-by: Max Filippov -- Thanks. -- Max