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 106B2C43381 for ; Wed, 13 Mar 2019 13:03:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C6D522183F for ; Wed, 13 Mar 2019 13:03:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552482235; bh=6pBFmBhRit/lXvLI6vi8fHZSx5zQ44s0Fq4INl6nWZA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=RzimQAkBKnxN8eqsYhs3dCiHCdT/s+OP6IorJ/T2OLvcJhCY4jg8JjcFjFetelOxd dO8IKlazp7oNud3kAfpIgBGpjwO8Xq6wMzNIk05Uea01kSD8eJqrQuu28fdsAn7uU4 0bhe2jlQ1a6/aOu0vkDrWD6PN/Q77RSEz5+Nd3IE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726255AbfCMNDy (ORCPT ); Wed, 13 Mar 2019 09:03:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:58532 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725832AbfCMNDy (ORCPT ); Wed, 13 Mar 2019 09:03:54 -0400 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (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 323072177E; Wed, 13 Mar 2019 13:03:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552482233; bh=6pBFmBhRit/lXvLI6vi8fHZSx5zQ44s0Fq4INl6nWZA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=mxZb5skCI62g94dwxg8F6BmNTSczq8mINcNicl/p73EpO2e3xLx+StIN4ah6B19FM dstMZ5ckd+m2uie13hyiwCiHdFF1s8vxlUCx5A3huvlbEdmjWiGbSNnLPbP/3rYi70 WFt+YICBXNTeAhxZjWc7WKDHnVHFCLp2XZ0nFdqg= Date: Wed, 13 Mar 2019 22:03:48 +0900 From: Masami Hiramatsu To: Tom Zanussi 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 Subject: Re: [RFC PATCH v3 0/5] tracing: common error_log for ftrace Message-Id: <20190313220348.d0481a0a5ad7de91e90dbadc@kernel.org> In-Reply-To: <1552409351.4293.22.camel@kernel.org> References: <20190305230646.e7f99c46f86c0e099ac0cd30@kernel.org> <20190312152605.00150aae7b781137005e9ebf@kernel.org> <1552409351.4293.22.camel@kernel.org> X-Mailer: Sylpheed 3.5.1 (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 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/barrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr > > 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/barrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr > > 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? Thank you, -- Masami Hiramatsu