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    SubjectRe: [PATCH 00/15] [git pull] for tip/tracing/ftrace

    * 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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