Messages in this thread | | | Date | Tue, 17 Feb 2009 11:42:13 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH 00/15] [git pull] for tip/tracing/ftrace |
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* Steven Rostedt <rostedt@goodmis.org> wrote:
> Ingo, > > This is a patch series that offers a variety of features. > > The first is to add: > > #### all functions enabled #### > > to set_ftrace_filter when all functions will be traced when function > tracing is on. > > The next is to add a :command: interface, and the module command: > > echo '*:mod:ext4' > set_ftrace_filter > > Will select all functions in the ext4 module. > > echo '!*write*:mod:ext4' > set_ftrace_filter > > will remove all functions with the characters 'write' and are > in ext4.
Very nice feature!
I'm wondering, would it be possible to somehow extend this to built-in drivers too, so that we get symmetry of usage independently of whether something is built in or a module? I suspect it needs some extensions to kbuild though ...
> Next we extend the :command: interface as well as add a way to > hook tracers to specific functions. Instead of tracing all functions > the same, this patch series adds a hash to be able to trace different > functions differently.
That's a nice extension too!
Small naming detail: instead of calling it a 'hook' (which really has a bad sound to it for various reasons), how about calling it a 'trigger' and/or a 'callback'?
> I implement a 'traceon' and 'traceoff' to have a function > start or stop tracing when it is hit. It also includes a > counter for the number of times to implement the trace on/off. > > echo '*_lock:traceon:4' > set_ftrace_filter > echo '*_unlock:traceoff:5' > set_ftrace_filter
if there's no counter specified, does it default to 1 [single-shot trigger] or infinity?
> This will have all functions that end with _lock turn on > tracing and all that end with _unlock disable it, 4 times > each. > > The following patches are in: > > git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git > > branch: tip/tracing/ftrace > > > Steven Rostedt (15): > ftrace: state that all functions are enabled in set_ftrace_filter > ftrace: add do_for_each_ftrace_rec and while_for_each_ftrace_rec > ftrace: rename ftrace_match to ftrace_match_records > ftrace: break up ftrace_match_records into smaller components > ftrace: add module command function filter selection > ftrace: enable filtering only when a function is filtered on > ftrace: add command interface for function selection > ftrace: convert ftrace_lock from a spinlock to mutex > ftrace: consolidate mutexes > ftrace: trace different functions with a different tracer > ring-buffer: add tracing_is_on to test if ring buffer is enabled > ftrace: add traceon traceoff commands to enable/disable the buffers > ftrace: show selected functions in set_ftrace_filter > ftrace: add pretty print to selected fuction traces > ftrace: add pretty print function for traceon and traceoff hooks > > ---- > include/linux/ftrace.h | 40 ++ > include/linux/ring_buffer.h | 2 + > kernel/trace/ftrace.c | 929 +++++++++++++++++++++++++++++++--------- > kernel/trace/ring_buffer.c | 9 + > kernel/trace/trace_functions.c | 163 +++++++ > 5 files changed, 946 insertions(+), 197 deletions(-)
Pulled into tip:tracing/ftrace, thanks Steve!
Ingo
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