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| author |   Li Zefan <lizf@cn.fujitsu.com> | 2009-07-01 10:47:05 +0800 |
|---|---|---|
| committer |   Ingo Molnar <mingo@elte.hu> | 2009-07-01 15:44:24 +0200 |
| commit | 020e5f85cb087a40572c8b8b2dd06292a14fa212 (patch) | |
| tree | d1bd09885693dd9d5e9db995cb0f7f58aa0e1bb8 /kernel/trace/trace_events.c | |
| parent | kprobes: Clean up insn_pages by using list instead of hlist (diff) | |
| download | linux-dev-020e5f85cb087a40572c8b8b2dd06292a14fa212.tar.xz linux-dev-020e5f85cb087a40572c8b8b2dd06292a14fa212.zip | |
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 <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A4ACE29.3010407@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/trace_events.c')
| -rw-r--r-- | kernel/trace/trace_events.c | 37 |
1 files changed, 33 insertions, 4 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 53c8fd376a88..fecac1314cbe 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -17,6 +17,8 @@ #include <linux/ctype.h> #include <linux/delay.h> +#include <asm/setup.h> + #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; } |