Messages in this thread | | | Subject | Re: [RFC][PATCH 11/18 v2] ftrace: Adde infrastructure to stop RCU unsafe checker from checking | From | Steven Rostedt <> | Date | Sat, 31 Aug 2013 16:40:04 -0400 |
| |
On Sat, 2013-08-31 at 12:52 -0700, Paul E. McKenney wrote: > On Sat, Aug 31, 2013 at 01:11:28AM -0400, Steven Rostedt wrote: > > From: "Steven Rostedt (Red Hat)" <rostedt@goodmis.org> > > > > This is a light weight way to keep the rcu checker from checking > > RCU safety. It adds a ftrace_unsafe_rcu_checker_disable/enable() > > that increments or decrements a counter respectively. When the > > counter is set, the RCU unsafe checker callback does not run the > > tests to see if RCU is safe or not. > > Please add something saying what we do instead of testing RCU safety. > Looks to me like it skips not only the tests, but also invoking the > callback, but I could easily be wrong.
Yeah, the change log sucks. I wrote the change logs after 1am and was half asleep. I see I wrote "Add" as "Adde" ;-)
> > > This is required by the graph tracer because the checks can cause > > the graph tracer to live lock the system by its own calls. > > > > It's also needed by the irqsoff tracer, because it may be called > > in RCU unsafe regions and if its internal functions get traced > > then the RCU unsafe checker may have some false positives. > > > > Signed-off-by: Steven Rostedt <rostedt@goodmis.org> > > With the augmented commit log as noted above: > > Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> >
Thanks, come Tuesday, I'll update the logs.
-- Steve
> > --- > > kernel/trace/trace.h | 12 +++++++++--- > > kernel/trace/trace_functions.c | 15 +++++++++++++++ > > 2 files changed, 24 insertions(+), 3 deletions(-) > > > > diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h > > index e551316..58e4c37 100644 > > --- a/kernel/trace/trace.h > > +++ b/kernel/trace/trace.h > > @@ -760,9 +760,6 @@ static inline int ftrace_graph_addr(unsigned long addr)
| |