From 26f255646e0ca6fde0e994e2a815ba2b31770dce Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Fri, 17 Jan 2014 15:11:44 -0600 Subject: [PATCH] tracing/README: Add event file usage to tracing mini-HOWTO It would be useful to have a cheat-sheet for everything under tracing/events/ alongside the existing text describing the other files in the tracing/ dir. Add short descriptions of the directories and files under events/ along with examples, similar to the existing text for the other files in tracing/. Also clean up a few minor alignment problems noticed when adding the new text. Link: http://lkml.kernel.org/r/1389993104.3040.445.camel@empanada Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 37 ++++++++++++++++++++++++++++++++++--- 1 file changed, 34 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 20c755e018ca..2ced5e5931b9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3523,9 +3523,9 @@ static const char readme_msg[] = #ifdef CONFIG_DYNAMIC_FTRACE "\n available_filter_functions - list of functions that can be filtered on\n" " set_ftrace_filter\t- echo function name in here to only trace these functions\n" - " accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" - " modules: Can select a group via module\n" - " Format: :mod:\n" + " accepts: func_full_name, *func_end, func_begin*, *func_middle*\n" + " modules: Can select a group via module\n" + " Format: :mod:\n" " example: echo :mod:ext3 > set_ftrace_filter\n" " triggers: a command to perform when function is hit\n" " Format: :[:count]\n" @@ -3573,6 +3573,37 @@ static const char readme_msg[] = " stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace traces\n" #endif #endif /* CONFIG_STACK_TRACER */ + " events/\t\t- Directory containing all trace event subsystems:\n" + " enable\t\t- Write 0/1 to enable/disable tracing of all events\n" + " events//\t- Directory containing all trace events for :\n" + " enable\t\t- Write 0/1 to enable/disable tracing of all events\n" + " filter\t\t- If set, only events passing filter are traced\n" + " events///\t- Directory containing control files for :\n" + " enable\t\t- Write 0/1 to enable/disable tracing of \n" + " filter\t\t- If set, only events passing filter are traced\n" + " trigger\t\t- If set, a command to perform when event is hit\n" + " Format: [:count][if ]\n" + " trigger: traceon, traceoff\n" + " enable_event::\n" + " disable_event::\n" +#ifdef CONFIG_STACKTRACE + " stacktrace\n" +#endif +#ifdef CONFIG_TRACER_SNAPSHOT + " snapshot\n" +#endif + " example: echo traceoff > events/block/block_unplug/trigger\n" + " echo traceoff:3 > events/block/block_unplug/trigger\n" + " echo 'enable_event:kmem:kmalloc:3 if nr_rq > 1' > events/block/block_unplug/trigger\n" + " The first disables tracing every time block_unplug is hit.\n" + " The second disables tracing the first 3 times block_unplug is hit.\n" + " The third enables the kmalloc event the first 3 times block_unplug\n" + " is hit and has value of greater than 1 for the 'nr_rq' event field.\n" + " To remove a trigger without a count:\n" + " echo '! > //trigger\n" + " To remove a trigger with a count:\n" + " echo '!:0 > //trigger\n" + " Filters can be ignored when removing a trigger.\n" ; static ssize_t