From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751659AbbAMMqm (ORCPT ); Tue, 13 Jan 2015 07:46:42 -0500 Received: from mail7.hitachi.co.jp ([133.145.228.42]:48703 "EHLO mail7.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750981AbbAMMqk (ORCPT ); Tue, 13 Jan 2015 07:46:40 -0500 Message-ID: <54B513A9.8070004@hitachi.com> Date: Tue, 13 Jan 2015 21:46:33 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Steven Rostedt Cc: LKML , vvs@sw.ru Subject: Re: Bug with jprobes and function graph tracer References: <20150108122016.0241f713@gandalf.local.home> <54B503F5.4020509@hitachi.com> <20150113072232.451c599b@gandalf.local.home> In-Reply-To: <20150113072232.451c599b@gandalf.local.home> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (2015/01/13 21:22), Steven Rostedt wrote: > On Tue, 13 Jan 2015 20:39:33 +0900 > Masami Hiramatsu wrote: > >> >> Yeah we should try to fix this, but not so high priority since jprobe >> is not used so frequently. I guess one easy solution is adding notrace >> to all jprobe handlers for hiding it from function-graph tracer. >> If there is a way to check a function is notrace or not, I can use that >> in register_jprobe and reject it if the handler is not "notrace"ed. :) > > Adding notrace should be the last resort. Every notrace in the kernel > makes function tracing a little more useless. It bothers me even more > when notrace is added because of function graph tracing but the > function still works for function tracing. I see. > > I worked on this for the last few days and have a patch that fixes the > problem. I'll be posting it later today. It also uncovered another > unrelated bug that I worked on yesterday, otherwise I would have posted > these fixes already. Great! I look forward that! :) > > I have a fix for the other bug now but it needs to be cleaned up > (remove all the debugging prints from it). When that's complete I'll > post the patches and get them ready for mainline and stable. Thank you, > > Thanks, > > -- Steve > -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Research Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com