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=-1.1 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 9E08BC43381 for ; Wed, 13 Mar 2019 14:09:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6CF312171F for ; Wed, 13 Mar 2019 14:09:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552486179; bh=3+2I98o1I9ZiI96NR/5ZyEUSMXPnk3CzMGlkkeqLB30=; h=Subject:From:To:Cc:Date:In-Reply-To:References:List-ID:From; b=Jfdz4gbqHZYSqz2XXE504fXIAqbRjB3EWV+8QARCkgLnYYg7r8Q8SgCQIMaK0H5zJ hoOzns9BC4KZCgR/Nu0z88odasyTB/VE0/IVoW1C34Zw7MQb25FMag7/xfpUEwxpxH Fy5H12CIW1u9a7+RnVa60vczWQJEaWBA8jpe7r8w= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726973AbfCMOJi (ORCPT ); Wed, 13 Mar 2019 10:09:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:39780 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726530AbfCMOJg (ORCPT ); Wed, 13 Mar 2019 10:09:36 -0400 Received: from tzanussi-mobl (c-98-220-238-81.hsd1.il.comcast.net [98.220.238.81]) (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 0F3402147C; Wed, 13 Mar 2019 14:09:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552486175; bh=3+2I98o1I9ZiI96NR/5ZyEUSMXPnk3CzMGlkkeqLB30=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=qJW10C3wPFIZceA3hWQLpZ01njnBt5nl8W+MQ1DtRaCj8qGHL2tAgOW2opuKCdGfZ I4xlIJs0xsI7gzc4L8RS7yoBZ7M80DJhNmxp0Q+kAiDT+8xVLfzm3vpMCvBTFwV4s4 JQQtm8lKPKR/UO1o0w9kBtzT9sk21JEBZjAMS8XI= Message-ID: <1552486173.4293.27.camel@kernel.org> Subject: Re: [RFC PATCH v3 0/5] tracing: common error_log for ftrace From: Tom Zanussi To: Masami Hiramatsu Cc: rostedt@goodmis.org, tglx@linutronix.de, namhyung@kernel.org, bigeasy@linutronix.de, joel@joelfernandes.org, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org Date: Wed, 13 Mar 2019 09:09:33 -0500 In-Reply-To: <20190313220348.d0481a0a5ad7de91e90dbadc@kernel.org> References: <20190305230646.e7f99c46f86c0e099ac0cd30@kernel.org> <20190312152605.00150aae7b781137005e9ebf@kernel.org> <1552409351.4293.22.camel@kernel.org> <20190313220348.d0481a0a5ad7de91e90dbadc@kernel.org> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.1-1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Masami, On Wed, 2019-03-13 at 22:03 +0900, Masami Hiramatsu wrote: > On Tue, 12 Mar 2019 11:49:11 -0500 > Tom Zanussi wrote: > > > Hi Masami, > > > > On Tue, 2019-03-12 at 15:26 +0900, Masami Hiramatsu wrote: > > > Hi Tom, > > > > > > On Tue, 5 Mar 2019 23:06:46 +0900 > > > Masami Hiramatsu wrote: > > > > > > > On Mon, 4 Mar 2019 17:36:43 -0600 > > > > > Changes from v2: > > > > > > > > > > - Added [n] numbering as suggested by Masami > > > > > > Hmm, this seems a bit different what I suggested. > > > > > > I'm trying to port probe event's error report on > > > your error log, and I found that the number is > > > just shifted as below. > > > > > > When I filled the log with errors. > > > ============= > > > /sys/kernel/debug/tracing # cat error_log > > > [1] trace_kprobe: error: Invalid unsigned integer string > > > Command: r10aa00:foo/bar vfs > > > ^ > > > ... > > > > > > [7] trace_kprobe: error: Group name must follow C naming > > > convention > > > Command: p:a-b/bar vfs_read > > > ^ > > > [8] trace_kprobe: error: Event name is too long > > > Command: > > > p:a/barrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr > > > rrrr > > > rrrrrrrrrrr vfs_read > > > ============= > > > > > > And do one more error, > > > > > > ============= > > > /sys/kernel/debug/tracing # cat error_log > > > [1] trace_kprobe: error: Maxactive is too big > > > Command: r0xaa00:foo/bar vfs > > > > > > .... > > > > > > [7] trace_kprobe: error: Event name is too long > > > Command: > > > p:a/barrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr > > > rrrr > > > rrrrrrrrrrr vfs_read > > > ^ > > > [8] trace_kprobe: error: Event name must follow C naming > > > convention > > > Command: p:a/bar.c vfs_read > > > ^ > > > ============= > > > > > > The number of logs are changed :( This can confuse users. > > > I think it is better to keep the number as a unique number for > > > each entry as below. > > > > > > > Hmm, that makes sense, but I wonder if that will also confuse > > users, > > when the log wraps around and no longer starts at [1] and there's > > no > > way to retrieve the previous errors. > > It is OK, that is same as dmesg. If user needs to keep watching it, > it should be dumped to disk by a daemon. > > > > > I took your suggestion as a way mainly to clearly delineate each > > error, > > since without the [number] or something similar, they all kind of > > run > > together. > > > > Not sure what advantage numbering itself provides - would some > > other > > non-numbered separator work? > > What about timestamp, similar to dmesg? > Yeah, I think that makes more sense - unlike the counter, there's no sense that you may be missing some prior messages. Thanks, Tom > Thank you, > > >