From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753278Ab1KXTDO (ORCPT ); Thu, 24 Nov 2011 14:03:14 -0500 Received: from he.sipsolutions.net ([78.46.109.217]:37994 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751031Ab1KXTDM (ORCPT ); Thu, 24 Nov 2011 14:03:12 -0500 Subject: [PATCH v3] printk: add console output tracing From: Johannes Berg To: Frederic Weisbecker Cc: Steven Rostedt , Christoph Hellwig , LKML , Ingo Molnar In-Reply-To: <20111124154519.GB18579@somewhere.redhat.com> (sfid-20111124_164601_383201_AB72557F) References: <20111117145502.GA18437@somewhere> <1321541877.3997.31.camel@jlt3.sipsolutions.net> <20111117150040.GB18437@somewhere> <1321543268.3997.40.camel@jlt3.sipsolutions.net> <20111118184401.GA24787@somewhere.redhat.com> <1321641975.10266.73.camel@jlt3.sipsolutions.net> <20111118185449.GB24787@somewhere.redhat.com> <1321642752.10266.75.camel@jlt3.sipsolutions.net> <20111123131622.GA10669@somewhere.redhat.com> <1322140919.5366.17.camel@jlt3.sipsolutions.net> <20111124154519.GB18579@somewhere.redhat.com> (sfid-20111124_164601_383201_AB72557F) Content-Type: text/plain; charset="UTF-8" Date: Thu, 24 Nov 2011 20:03:08 +0100 Message-ID: <1322161388.5366.54.camel@jlt3.sipsolutions.net> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Johannes Berg Add a printk.console trace point to record any printk messages into the trace, regardless of the current console loglevel. This can help correlate (existing) printk debugging with other tracing. Signed-off-by: Johannes Berg --- v2: remove extra file v3: simplify length of __dynamic_array, thanks Frederic include/trace/events/printk.h | 41 +++++++++++++++++++++++++++++++++++++++++ kernel/printk.c | 5 +++++ 2 files changed, 46 insertions(+) --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ b/include/trace/events/printk.h 2011-11-24 20:02:21.000000000 +0100 @@ -0,0 +1,41 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM printk + +#if !defined(_TRACE_PRINTK_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_PRINTK_H + +#include + +TRACE_EVENT_CONDITION(console, + TP_PROTO(const char *log_buf, unsigned start, unsigned end, + unsigned log_buf_len), + + TP_ARGS(log_buf, start, end, log_buf_len), + + TP_CONDITION(start != end), + + TP_STRUCT__entry( + __dynamic_array(char, msg, end - start + 1) + ), + + TP_fast_assign( + if ((start & (log_buf_len - 1)) > (end & (log_buf_len - 1))) { + memcpy(__get_dynamic_array(msg), + log_buf + (start & (log_buf_len - 1)), + log_buf_len - (start & (log_buf_len - 1))); + memcpy((char *)__get_dynamic_array(msg) + + log_buf_len - (start & (log_buf_len - 1)), + log_buf, end & (log_buf_len - 1)); + } else + memcpy(__get_dynamic_array(msg), + log_buf + (start & (log_buf_len - 1)), + end - start); + ((char *)__get_dynamic_array(msg))[end - start] = 0; + ), + + TP_printk("%s", __get_str(msg)) +); +#endif /* _TRACE_PRINTK_H */ + +/* This part must be outside protection */ +#include --- a/kernel/printk.c 2011-11-24 09:38:53.000000000 +0100 +++ b/kernel/printk.c 2011-11-24 09:42:37.000000000 +0100 @@ -44,6 +44,9 @@ #include +#define CREATE_TRACE_POINTS +#include + /* * Architectures can override it: */ @@ -542,6 +545,8 @@ MODULE_PARM_DESC(ignore_loglevel, "ignor static void _call_console_drivers(unsigned start, unsigned end, int msg_log_level) { + trace_console(&LOG_BUF(0), start, end, log_buf_len); + if ((msg_log_level < console_loglevel || ignore_loglevel) && console_drivers && start != end) { if ((start & LOG_BUF_MASK) > (end & LOG_BUF_MASK)) {