[PATCH 2/2] ftrace: Use the rcu _notrace variants for rcu_dereference_raw() and friends

2013-05-29 Thread Steven Rostedt
From: Steven Rostedt As rcu_dereference_raw() under RCU debug config options can add quite a bit of checks, and that tracing uses rcu_dereference_raw(), these checks happen with the function tracer. The function tracer also happens to trace these debug checks too. This added overhead can livelock

Re: [PATCH 2/2] ftrace: Use the rcu _notrace variants for rcu_dereference_raw() and friends

2013-05-28 Thread Paul E. McKenney
On Tue, May 28, 2013 at 02:38:43PM -0400, Steven Rostedt wrote: > As rcu_dereference_raw() under RCU debug config options can add quite a > bit of checks, and that tracing uses rcu_dereference_raw(), these checks > happen with the function tracer. The function tracer also happens to trace > these d

[PATCH 2/2] ftrace: Use the rcu _notrace variants for rcu_dereference_raw() and friends

2013-05-28 Thread Steven Rostedt
As rcu_dereference_raw() under RCU debug config options can add quite a bit of checks, and that tracing uses rcu_dereference_raw(), these checks happen with the function tracer. The function tracer also happens to trace these debug checks too. This added overhead can livelock the system. Have the