Received: by 2002:a25:4158:0:0:0:0:0 with SMTP id o85csp861800yba; Fri, 3 May 2019 11:41:07 -0700 (PDT) X-Google-Smtp-Source: APXvYqzLyn/RAY12wEzha2VScSc53qG+ozjCquec3SLc9kk2Qn556qyxclcRHqJ2AfvsGtr9TzRj X-Received: by 2002:a17:902:4a0c:: with SMTP id w12mr12786445pld.52.1556908866988; Fri, 03 May 2019 11:41:06 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1556908866; cv=none; d=google.com; s=arc-20160816; b=Zw8c7gba5pMVPj738s3iztx56lcUO4bzfdAsoJOK6tcAI+RUReEhS5clbNwhOjm4bI +ZtantYJASQtqq7Z7pOibmmnVPUctwdXV8hMvZp8MSAMVPTqHYe8QnF/VZEqZ4DALhVq Uu3R9FimHRsgjEWGdxgwyDTiP88ZQmfsvkiwvGKzPcs9YvBCReJ79NqBwJNVKz/inRuA rhja5HIf8TtJK1ZASF0pUzOGZMYJpumC4VHyZjoOKFWM9QF5Rfyb79ANr0nfVxHgWUNF dVOC68xX7UpkwQpH7ViNJUQwJQJfsNUR4WGVa2Uw2NteT4uEz1JCAQr5JfmB+smdcIk+ vJVA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:dkim-signature; bh=nkTgO54YjURMiG1DVkIm06XESiWS/JR9PgrxKa00YCg=; b=FX2gXNtXHvyx0mjuCL9lJ4o3EDSYMzWi3k+25ZHRbfAdmwWPKSv1iSbRpmCC8mSBGO rtzIyrLvm5uqjTzYvmcw0rZ/GrrjJRE23JhQrDLR/ZKfAIPhSVPSojxOn5IAP0lGfuKI dT1uzVnSVr9axUTo5nOF4fcU3Dk56tR8khxtuHvVhnskWVB7+lgIQEafIWUcN61nIokC qcd6l0TutfjV/KiWB+gcM2Ma4ALN5qCinkYalI52MvBxFZCAcNqg2P+GZ0GwUbjhtcfN 7UihFWgvP5dBrHs675rKi3ZgoumOJ+uXa7+hIT8v7y1pICL5yLELIodpzrrpiPZ8ZLa5 koWQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=a9tcXeVU; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id a15si3483079pgd.166.2019.05.03.11.40.51; Fri, 03 May 2019 11:41:06 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=a9tcXeVU; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728514AbfECQou (ORCPT + 99 others); Fri, 3 May 2019 12:44:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:37496 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727899AbfECQot (ORCPT ); Fri, 3 May 2019 12:44:49 -0400 Received: from mail-wr1-f50.google.com (mail-wr1-f50.google.com [209.85.221.50]) (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 9CBCC214DA for ; Fri, 3 May 2019 16:44:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556901888; bh=8cw3huy9JgI135+NqQSe0fA379tB3gSlEfIQFk7nPPI=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=a9tcXeVU+XVrv+XaQ98EQO+7o9VnoEC7qSeG5XSuDT3JZciuL59Dzppqzc87hwVPY d1bcbxf1pRtY3i6X0cXOTdUWyCZUgF+YFk2nFiABIc3rYcvNfN9mf9Qns0ClUKCaWC NgsTgylYZrf5x8w+imb6NLWJzPx1d9C9hZXqJ0KA= Received: by mail-wr1-f50.google.com with SMTP id l2so8665263wrb.9 for ; Fri, 03 May 2019 09:44:48 -0700 (PDT) X-Gm-Message-State: APjAAAUOGdZGu4Y9Ru8vI4H/asnI5pvvd8EJa/p8PtoqXXVRCyBNOLZw kzKM/gu2yxG5NlAdERXf+eKAHYdPX+y5TBEUOKJbtA== X-Received: by 2002:adf:ec42:: with SMTP id w2mr5212912wrn.77.1556901887167; Fri, 03 May 2019 09:44:47 -0700 (PDT) MIME-Version: 1.0 References: <20190502181811.GY2623@hirez.programming.kicks-ass.net> <20190502202146.GZ2623@hirez.programming.kicks-ass.net> <20190502185225.0cdfc8bc@gandalf.local.home> <20190502193129.664c5b2e@gandalf.local.home> <20190502195052.0af473cf@gandalf.local.home> <20190503092959.GB2623@hirez.programming.kicks-ass.net> <20190503092247.20cc1ff0@gandalf.local.home> <2045370D-38D8-406C-9E94-C1D483E232C9@amacapital.net> <20190503123126.3a2801be@gandalf.local.home> <20190503163527.GI2606@hirez.programming.kicks-ass.net> In-Reply-To: <20190503163527.GI2606@hirez.programming.kicks-ass.net> From: Andy Lutomirski Date: Fri, 3 May 2019 09:44:35 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions To: Peter Zijlstra Cc: Steven Rostedt , Linus Torvalds , Linux List Kernel Mailing , Ingo Molnar , Andrew Morton , Andy Lutomirski , Nicolai Stange , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , "the arch/x86 maintainers" , Josh Poimboeuf , Jiri Kosina , Miroslav Benes , Petr Mladek , Joe Lawrence , Shuah Khan , Konrad Rzeszutek Wilk , Tim Chen , Sebastian Andrzej Siewior , Mimi Zohar , Juergen Gross , Nick Desaulniers , Nayna Jain , Masahiro Yamada , Joerg Roedel , "open list:KERNEL SELFTEST FRAMEWORK" , stable 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, May 3, 2019 at 9:35 AM Peter Zijlstra wrote: > > On Fri, May 03, 2019 at 12:31:26PM -0400, Steven Rostedt wrote: > > I guess the real question is, what's the performance impact of doing > > that? > > Is there anyone that considers i386 a performance platform? Not me. As far as I'm concerned, I will basically always gladly trade several cycles for simplicity on 32-bit. --Andy