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=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 8DCF8C43441 for ; Fri, 9 Nov 2018 15:16:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 50110208A3 for ; Fri, 9 Nov 2018 15:16:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="y/OjEtzQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 50110208A3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728322AbeKJA5c (ORCPT ); Fri, 9 Nov 2018 19:57:32 -0500 Received: from mail.kernel.org ([198.145.29.99]:50932 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727828AbeKJA5c (ORCPT ); Fri, 9 Nov 2018 19:57:32 -0500 Received: from mail-wm1-f53.google.com (mail-wm1-f53.google.com [209.85.128.53]) (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 3E62C208E3 for ; Fri, 9 Nov 2018 15:16:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541776591; bh=WaBlzxzS+GDCiqnZ0/Mh6MnWrYZN9nBbL8DUB34u2Ck=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=y/OjEtzQcVq39oINKXhslHiHYL1wpab30/AyJIeBdkmRyo47TmviWGY92UruxOQG6 qI3C+MfeqAMClpE+V61qkeQ2RilMXAJ02E6sWX1qmKdzo7F++19dHtUHWPqrac7mSc LCFLhvhsbdCGKx7u92Bk+2jR3VxkEK/9hUjUqplI= Received: by mail-wm1-f53.google.com with SMTP id r63-v6so2357354wma.4 for ; Fri, 09 Nov 2018 07:16:31 -0800 (PST) X-Gm-Message-State: AGRZ1gItmBqJQxulMyVRNltQFsUox1GDj24m0a1/yePOPrVpgkij47je 6YJbhtKzpp7NnAiUY4zP4t/CfVrt6VdPsqwJLiCxXw== X-Google-Smtp-Source: AJdET5cqL1y1ZJrXzH8QRaJ3J3MvSbs1Tg4+ib+LZSzb+nN9SVxNpPY6djSzEYGJlwEH5XdVKiH0XuFT5P0symjevf4= X-Received: by 2002:a1c:ccb:: with SMTP id 194-v6mr5452105wmm.102.1541776589693; Fri, 09 Nov 2018 07:16:29 -0800 (PST) MIME-Version: 1.0 References: <20181109072811.GB86700@gmail.com> In-Reply-To: <20181109072811.GB86700@gmail.com> From: Andy Lutomirski Date: Fri, 9 Nov 2018 07:16:17 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH RFC 0/3] Static calls To: Ingo Molnar Cc: Josh Poimboeuf , LKML , X86 ML , Ard Biesheuvel , Andrew Lutomirski , Steven Rostedt , Peter Zijlstra , Thomas Gleixner , Linus Torvalds , Masami Hiramatsu , Jason Baron , Jiri Kosina , David Laight , Borislav Petkov 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 Thu, Nov 8, 2018 at 11:28 PM Ingo Molnar wrote: > > > All other usecases are bonus, but it would certainly be interesting to > investigate the impact of using these APIs for tracing: that too is a > feature enabled everywhere but utilized only by a small fraction of Linux > users - so literally every single cycle or instruction saved or hot-path > shortened is a major win. For tracing, we'd want static_call_set_to_nop() or something like that, right? --Andy