From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755317Ab1KPRA7 (ORCPT ); Wed, 16 Nov 2011 12:00:59 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:45997 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753245Ab1KPRA6 (ORCPT ); Wed, 16 Nov 2011 12:00:58 -0500 X-Authority-Analysis: v=2.0 cv=JOm5Qr2b c=1 sm=0 a=ZycB6UtQUfgMyuk2+PxD7w==:17 a=l4wf8OQxcBQA:10 a=5SG0PmZfjMsA:10 a=IkcTkHD0fZMA:10 a=WcGvJwXxC1aDNIH_oQkA:9 a=QEXdDO2ut3YA:10 a=ZycB6UtQUfgMyuk2+PxD7w==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.80.29 Subject: Re: [PATCH] tracing: add trace console From: Steven Rostedt To: Johannes Berg Cc: Christoph Hellwig , LKML , Frederic Weisbecker , Ingo Molnar In-Reply-To: <1321461902.4502.14.camel@jlt3.sipsolutions.net> References: <1321438728.4773.16.camel@jlt3.sipsolutions.net> <20111116151037.GA26166@infradead.org> <1321456652.4502.12.camel@jlt3.sipsolutions.net> <1321461693.4181.26.camel@frodo> <1321461902.4502.14.camel@jlt3.sipsolutions.net> Content-Type: text/plain; charset="UTF-8" Date: Wed, 16 Nov 2011 12:00:56 -0500 Message-ID: <1321462856.4181.28.camel@frodo> Mime-Version: 1.0 X-Mailer: Evolution 2.32.3 (2.32.3-1.fc14) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2011-11-16 at 17:45 +0100, Johannes Berg wrote: > I briefly looked at it just after writing the email, but quickly got > lost in printk.c because of the multi-line handling it has. We could > instead trace each call to printk(), so the multi-line stuff would end > up in multiple events, but all of that code is too much vodoo for me :) Here's what can go into printk.c: diff --git a/kernel/printk.c b/kernel/printk.c index 1455a0d..4b8445a 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -542,6 +542,7 @@ MODULE_PARM_DESC(ignore_loglevel, "ignore loglevel setting, to" static void _call_console_drivers(unsigned start, unsigned end, int msg_log_level) { + trace_console(&LOG_BUF(start), end - start); if ((msg_log_level < console_loglevel || ignore_loglevel) && console_drivers && start != end) { if ((start & LOG_BUF_MASK) > (end & LOG_BUF_MASK)) { And then you can make a TRACE_EVENT(console) that takes a buffer and a len, and write that to the ring buffer. -- Steve