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  1. May 27, 2008
    • Steven Rostedt's avatar
      ftrace: set_ftrace_notrace feature · 41c52c0d
      Steven Rostedt authored 
      

While debugging latencies in the RT kernel, I found that it would be nice
to be able to filter away functions from the trace than just to filter
on functions.

I added a new interface to the debugfs tracing directory called

  set_ftrace_notrace

When dynamic frace is enabled, this lets you filter away functions that will
not be recorded in the trace. It is similar to adding 'notrace' to those
functions but by doing it without recompiling the kernel.

Here's how set_ftrace_filter and set_ftrace_notrace interact. Remember, if
set_ftrace_filter is set, it removes all functions from the trace execpt for
those listed in the set_ftrace_filter. set_ftrace_notrace will prevent those
functions from being traced.

If you were to set one function in both set_ftrace_filter and
set_ftrace_notrace and that function was the same, then you would end up
with an empty trace.

the set of functions to trace is:

  set_ftrace_filter == empty then

     all functions not in set_ftrace_notrace

  else

     set of the set_ftrace_filter and not in set of set_ftrace_notrace.

Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      41c52c0d
    • Steven Rostedt's avatar
      ftrace: remove printks from irqsoff trace · da89a7a2
      Steven Rostedt authored 
      

Printing out new max latencies was fine for the old RT tracer. But for
mainline it is a bit messy. We also need to test if the run queue
is locked before we can do the print. This means that we may not be
printing out latencies if the run queue is locked on another CPU.
This produces inconsistencies in the output.

This patch simply removes the print altogether.

Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Cc: pq@iki.fi
Cc: proski@gnu.org
Cc: sandmann@redhat.com
Cc: a.p.zijlstra@chello.nl
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      da89a7a2
    • Steven Rostedt's avatar
      ftrace: add function tracing to wake up tracing · 7e18d8e7
      Steven Rostedt authored 
      

This patch adds function tracing to the functions that are called
on the CPU of the task being traced.

Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Cc: pq@iki.fi
Cc: proski@gnu.org
Cc: sandmann@redhat.com
Cc: a.p.zijlstra@chello.nl
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      7e18d8e7
    • Steven Rostedt's avatar
      ftrace: move ftrace_special to trace.c · 4902f884
      Steven Rostedt authored 
      

Move the ftrace_special out of sched_switch to trace.c.

Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Cc: pq@iki.fi
Cc: proski@gnu.org
Cc: sandmann@redhat.com
Cc: a.p.zijlstra@chello.nl
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      4902f884
    • Steven Rostedt's avatar
      ftrace: limit use of check pages · 19384c03
      Steven Rostedt authored 
      

The check_pages function is called often enough that it can cause problems
with trace outputs or even bringing the system to a halt.

This patch limits the check_pages to the places that are most likely to
have problems. The check is made at the flip between the global array and
the max save array, as well as when the size of the buffers changes and
the self tests.

This patch also removes the BUG_ON from check_pages and replaces it with
a WARN_ON and disabling of the tracer.

Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Cc: pq@iki.fi
Cc: proski@gnu.org
Cc: sandmann@redhat.com
Cc: a.p.zijlstra@chello.nl
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      19384c03
  3. May 25, 2008
  5. May 24, 2008