From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755958AbZGAOB5 (ORCPT ); Wed, 1 Jul 2009 10:01:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755873AbZGAOBq (ORCPT ); Wed, 1 Jul 2009 10:01:46 -0400 Received: from hera.kernel.org ([140.211.167.34]:43301 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755871AbZGAOBn (ORCPT ); Wed, 1 Jul 2009 10:01:43 -0400 Date: Wed, 1 Jul 2009 14:01:06 GMT From: tip-bot for Li Zefan To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, fweisbec@gmail.com, rostedt@goodmis.org, lizf@cn.fujitsu.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, fweisbec@gmail.com, lizf@cn.fujitsu.com, rostedt@goodmis.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <4A4ACE29.3010407@cn.fujitsu.com> References: <4A4ACE29.3010407@cn.fujitsu.com> Subject: [tip:tracing/core] tracing/events: Add trace_event boot option Message-ID: Git-Commit-ID: 020e5f85cb087a40572c8b8b2dd06292a14fa212 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Wed, 01 Jul 2009 14:01:07 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 020e5f85cb087a40572c8b8b2dd06292a14fa212 Gitweb: http://git.kernel.org/tip/020e5f85cb087a40572c8b8b2dd06292a14fa212 Author: Li Zefan AuthorDate: Wed, 1 Jul 2009 10:47:05 +0800 Committer: Ingo Molnar CommitDate: Wed, 1 Jul 2009 15:44:24 +0200 tracing/events: Add trace_event boot option We already have ftrace= boot option, and this adds a similar boot option for trace events, so allow trace events to be enabled at boot, for boot debugging purpose. Signed-off-by: Li Zefan Cc: Steven Rostedt Cc: Frederic Weisbecker LKML-Reference: <4A4ACE29.3010407@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- Documentation/kernel-parameters.txt | 5 ++++ Documentation/trace/events.txt | 9 ++++++++ kernel/trace/trace.c | 4 +- kernel/trace/trace.h | 3 ++ kernel/trace/trace_events.c | 37 +++++++++++++++++++++++++++++++--- 5 files changed, 52 insertions(+), 6 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index d3f41db..2582e7a 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2478,6 +2478,11 @@ and is between 256 and 4096 characters. It is defined in the file trace_buf_size=nn[KMG] [FTRACE] will set tracing buffer size. + trace_event=[event-list] + [FTRACE] Set and start specified trace events in order + to facilitate early boot debugging. + See also Documentation/trace/events.txt + trix= [HW,OSS] MediaTrix AudioTrix Pro Format: ,,,,,,,, diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt index f157d75..2bcc8d4 100644 --- a/Documentation/trace/events.txt +++ b/Documentation/trace/events.txt @@ -83,6 +83,15 @@ When reading one of these enable files, there are four results: X - there is a mixture of events enabled and disabled ? - this file does not affect any event +2.3 Boot option +--------------- + +In order to facilitate early boot debugging, use boot option: + + trace_event=[event-list] + +The format of this boot option is the same as described in section 2.1. + 3. Defining an event-enabled tracepoint ======================================= diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3aa0a0d..bdb3afc 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -49,7 +49,7 @@ unsigned long __read_mostly tracing_thresh; * On boot up, the ring buffer is set to the minimum size, so that * we do not waste memory on systems that are not using tracing. */ -static int ring_buffer_expanded; +int ring_buffer_expanded; /* * We need to change this state when a selftest is running. @@ -63,7 +63,7 @@ static bool __read_mostly tracing_selftest_running; /* * If a tracer is running, we do not want to run SELFTEST. */ -static bool __read_mostly tracing_selftest_disabled; +bool __read_mostly tracing_selftest_disabled; /* For tracers that don't implement custom flags */ static struct tracer_opt dummy_tracer_opt[] = { diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 3548ae5..52eb0d8 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -517,6 +517,9 @@ extern unsigned long ftrace_update_tot_cnt; extern int DYN_FTRACE_TEST_NAME(void); #endif +extern int ring_buffer_expanded; +extern bool tracing_selftest_disabled; + #ifdef CONFIG_FTRACE_STARTUP_TEST extern int trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr); diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 53c8fd3..fecac13 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -17,6 +17,8 @@ #include #include +#include + #include "trace_output.h" #define TRACE_SYSTEM "TRACE_SYSTEM" @@ -1133,6 +1135,18 @@ struct notifier_block trace_module_nb = { extern struct ftrace_event_call __start_ftrace_events[]; extern struct ftrace_event_call __stop_ftrace_events[]; +static char bootup_event_buf[COMMAND_LINE_SIZE] __initdata; + +static __init int setup_trace_event(char *str) +{ + strlcpy(bootup_event_buf, str, COMMAND_LINE_SIZE); + ring_buffer_expanded = 1; + tracing_selftest_disabled = 1; + + return 1; +} +__setup("trace_event=", setup_trace_event); + static __init int event_trace_init(void) { struct ftrace_event_call *call; @@ -1140,6 +1154,8 @@ static __init int event_trace_init(void) struct dentry *entry; struct dentry *d_events; int ret; + char *buf = bootup_event_buf; + char *token; d_tracer = tracing_init_dentry(); if (!d_tracer) @@ -1185,6 +1201,19 @@ static __init int event_trace_init(void) &ftrace_event_format_fops); } + while (true) { + token = strsep(&buf, ","); + + if (!token) + break; + if (!*token) + continue; + + ret = ftrace_set_clr_event(token, 1); + if (ret) + pr_warning("Failed to enable trace event: %s\n", token); + } + ret = register_module_notifier(&trace_module_nb); if (ret) pr_warning("Failed to register trace events module notifier\n"); @@ -1392,10 +1421,10 @@ static __init void event_trace_self_test_with_function(void) static __init int event_trace_self_tests_init(void) { - - event_trace_self_tests(); - - event_trace_self_test_with_function(); + if (!tracing_selftest_disabled) { + event_trace_self_tests(); + event_trace_self_test_with_function(); + } return 0; }