tracing: Prevent buffer overwrite disabled for latency tracers
authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>
Thu, 14 Mar 2013 19:03:53 +0000 (15:03 -0400)
committerSteven Rostedt <rostedt@goodmis.org>
Fri, 15 Mar 2013 03:40:21 +0000 (23:40 -0400)
commit613f04a0f51e6e68ac6fe571ab79da3c0a5eb4da
tree2bc6da65edff6669f68010a22595861af26fe44d
parent80902822658aab18330569587cdb69ac1dfdcea8
tracing: Prevent buffer overwrite disabled for latency tracers

The latency tracers require the buffers to be in overwrite mode,
otherwise they get screwed up. Force the buffers to stay in overwrite
mode when latency tracers are enabled.

Added a flag_changed() method to the tracer structure to allow
the tracers to see what flags are being changed, and also be able
to prevent the change from happing.

Cc: stable@vger.kernel.org
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
kernel/trace/trace.c
kernel/trace/trace.h
kernel/trace/trace_irqsoff.c
kernel/trace/trace_sched_wakeup.c