From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756977Ab1KPRF6 (ORCPT ); Wed, 16 Nov 2011 12:05:58 -0500 Received: from mx1.redhat.com ([209.132.183.28]:31210 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754858Ab1KPRF5 (ORCPT ); Wed, 16 Nov 2011 12:05:57 -0500 Subject: Re: [PATCH] tracing: add trace console From: Steven Rostedt To: Johannes Berg Cc: Christoph Hellwig , LKML , Frederic Weisbecker , Ingo Molnar In-Reply-To: <1321462856.4181.28.camel@frodo> 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> <1321462856.4181.28.camel@frodo> Content-Type: text/plain; charset="UTF-8" Organization: Red Hat Inc Date: Wed, 16 Nov 2011 12:05:45 -0500 Message-ID: <1321463145.4181.30.camel@frodo> Mime-Version: 1.0 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 12:00 -0500, Steven Rostedt wrote: > 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); And since we don't want to trace when end == start, we can use TRACE_EVENT_CONDITION() and have cond be: len > 0. (where len is the parameter that takes the end - start.) This will keep the branch to test len > 0 inside the tracepoint, and it wont affect the logic when tracing is disabled. -- Steve > if ((msg_log_level < console_loglevel || ignore_loglevel) && > console_drivers && start != end) { > if ((start & LOG_BUF_MASK) > (end & LOG_BUF_MASK)) { >