[Devel] Re: [PATCH 0/3] ftrace: updates for tip

[Ingo Molnar]

* Steven Rostedt <rostedt at goodmis.org> wrote:

> Ingo,
> 
> This series has three patches.
> 
> The first patch adds a new feature that I've been wanting to have for some
> time and Arjan even requested. That is to pick a function and only
> trace that function and its children. Dynamic ftrace and function
> graph needs to be enabled for this.
> 
> To do the above, I added a "trace" flags field in the task structure.
> The second patch uses this for the ftrace pid code. It searches for
> the task based on the pid and sets the trace flag, then in the
> ftrace function caller it only needs to check this flag.
> 
> This means we can now trace more than one pid without any more overhead.
> It also means that we should be able to use the name space code that
> the container guys want us to. But since I'm not very up on the
> namespace code, I'm still using just the normal 'pid'. I've Cc'd the
> container folks so perhaps they could write up a patch for me ;-)
> 
> Note: When writing to the set_ftrace_pid two things happen.
>  - The task with the matching pid gets the trace flag set.
>  - Any other task has its trace flag cleared.
>  #2 needs to be addressed when converting to pid name spaces.
>  Just because it is not enough to simply find the matching task.
>  It may be good enough to just clear all tasks and then find the
>  one that matches.
> 
> The last patch makes the function graph tracer honor the set_ftrace_pid.
> 
> The following patches are in:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
> 
>     branch: tip/devel
> 
> 
> Steven Rostedt (3):
>       ftrace: graph of a single function
>       ftrace: use task struct trace flag to filter on pid
>       ftrace: trace single pid for function graph tracer
> 
> ----
>  include/linux/ftrace.h |   46 +++++++++
>  include/linux/sched.h  |    4 +
>  kernel/trace/ftrace.c  |  257 +++++++++++++++++++++++++++++++++++++++++++++++-
>  kernel/trace/trace.c   |   11 ++
>  kernel/trace/trace.h   |   40 +++++++-
>  5 files changed, 353 insertions(+), 5 deletions(-)
> -- 

pulled, thanks Steve!

These are some very nice changes!

	Ingo
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