Received: by 2002:a25:4158:0:0:0:0:0 with SMTP id o85csp869195yba; Fri, 3 May 2019 11:49:48 -0700 (PDT) X-Google-Smtp-Source: APXvYqyJifMuLybJsZ6k/A/WXlzL8/0iRtMeyf3R9qeCitQxnGsniWU+8mNFFbMcUre7Znnjl/I1 X-Received: by 2002:a17:902:822:: with SMTP id 31mr12394596plk.41.1556909387908; Fri, 03 May 2019 11:49:47 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1556909387; cv=none; d=google.com; s=arc-20160816; b=PMEZ1xVx5XxpwzgoqcT+w5/5AbFUhxGIVYL+FcWXWOsYBXTJzCGoCyVV3QJmWDVIxW KDl4ekb1Gnu/BzngDMQgqWU9dEwnqwDHym3b7eld7BlP1/NYFv/8G6OFk8BziUxCTFcG 6zruFy2s+t+XeWMURuyeyzvOQqWa6XgeNqR8gAFM7e8fPejpICQjUAPr2U68KfHZuCYU +z/04U4WQuwKuDkXvwMKYv9BxURvwZPGQo7wxjrLD+oDFFZMuPcBmolUG8rsf1xYVYL9 Q70NTQtNm75llk/U4G9+klq9dFbY8kZMMnR98tQjhJIcY+yfnZsbTD8HNOOs35RiNEag q4xA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:mime-version :references:in-reply-to:message-id:subject:cc:to:from:date; bh=K7FZp3pW8pER/mvuTciDAfh7K8IflnUgdAfroXM9Y+c=; b=Wh5pzWYfuss40WFLAYxFBtMU9lTIz7wQi3RUTF9Gw/MaqykMEbbhU1P0Ert8sxcFui AjuqEtPja2TssytZUevprAFIb4E+7cqv9ZyhxGdu6f/wGViN8Y816Yl2fzQHPtf6JYzb ReF+ZVoLpRFC5Ex+PiU/0PEwSLIrvY+8QmJT+WxW4N+vuTKDM+ZcArjzNtL1rlK+WVvZ /q2/u9eUxhBBhV3tBzW+Xces2Wl34KYy5y7Fv+HQACJ76Xhe4MACk3RKzovOfrtvQ21W xvloENG8Sm+CZxTeW+vLWNFpexD0vWgfqJib8VWbPdO+JKs6jH5PYYnFbPGobiYBF8Bx b1XA== ARC-Authentication-Results: i=1; mx.google.com; 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 Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id l191si3314269pfc.213.2019.05.03.11.49.29; Fri, 03 May 2019 11:49:47 -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; 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 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728565AbfECQtL (ORCPT + 99 others); Fri, 3 May 2019 12:49:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:39242 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728056AbfECQtL (ORCPT ); Fri, 3 May 2019 12:49:11 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 0C20B2075C; Fri, 3 May 2019 16:49:07 +0000 (UTC) Date: Fri, 3 May 2019 12:49:06 -0400 From: Steven Rostedt To: Andy Lutomirski Cc: Peter Zijlstra , Linus Torvalds , Linux List Kernel Mailing , Ingo Molnar , Andrew Morton , 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 Subject: Re: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions Message-ID: <20190503124906.576c21f7@gandalf.local.home> In-Reply-To: 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> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 3 May 2019 09:44:35 -0700 Andy Lutomirski wrote: > 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. > So should I wait for a new PATCH 1 from Peter to implement it this way? I'd like to get this into the next merge window (although, I am marking it for stable since it fixes a bug for live kernel patching). Linus, what's your thoughts? -- Steve