[PATCH] Add documentation for trace commands mod, traceon/traceoff
in [Kernel]
|
Prev: perf: remove __weak function hw_perf_group_sched_in()
Next: perf: core, add group scheduling transactional APIs
From: Chase Douglas on 23 Apr 2010 12:20 The mod command went in as commit 64e7c440618998fd69eee6ab490b042d12248021 The traceon/traceoff commands when in as commit 23b4ff3aa479c9e3bb23cb6b2d0a97878399784a Signed-off-by: Chase Douglas <chase.douglas(a)canonical.com> --- Documentation/trace/ftrace.txt | 35 +++++++++++++++++++++++++++++++++++ 1 files changed, 35 insertions(+), 0 deletions(-) diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index 03485bf..64e08d5 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -155,6 +155,9 @@ of ftrace. Here is a list of some of the key files: to be traced. Echoing names of functions into this file will limit the trace to only those functions. + This interface also allows for commands to be used. See the + "Filter commands" section for more details. + set_ftrace_notrace: This has an effect opposite to that of @@ -1822,6 +1825,38 @@ this special filter via: echo > set_graph_function +Filter commands +--------------- + +A few commands are supported by the set_ftrace_filter interface. +Trace commands have the following format: + +<function>:<command>:<parameter> + +The following commands are supported: + +- mod + This command enables function filtering per module. The + parameter defines the module. For example, if only the write* + functions in the ext3 module are useful in a trace, echo + 'write*:mod:ext3' > set_ftrace_filter. This command interacts + with the filter in the same way as filtering based on function + names. Thus, adding more functions in a different module is + accomplished by appending (>>) to the filter file. Remove + specific module functions by prepending '!' + (!writeback*:mod:ext3). + +- traceon/traceoff + These commands turn tracing on and off when the specified + functions are hit. The parameter determines how many times the + tracing system is turned on and off. If unspecified, there is + no limit. For example, to disable tracing when a schedule bug + is hit the first 5 times, use '__schedule_bug:traceoff:5'. + These commands are cumulative whether or not they are appended + to set_ftrace_filter. To remove a command, prepend it by '!' + and drop the parameter (!__schedule_bug:traceoff). + + trace_pipe ---------- -- 1.7.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |