On Wed, Oct 05, 2016 at 05:18:09PM +0300, Nikolay Borisov wrote:
>
>
> On 10/05/2016 05:03 PM, Paul E. McKenney wrote:
> > On Wed, Oct 05, 2016 at 10:06:21AM +0300, Nikolay Borisov wrote:
> >> Explicitly state that enabling RCU_TRACE enables more
> >> tracepoints and not just "additional tracing".
> >>
> >> Signed-off-by: Nikolay Borisov <[email protected]>
> >> ---
> >>
> >> Hello Paul,
> >>
> >> Following our latest conversation re. enabling RCU tracing
> >> I had to actually go and look into the code to see which
> >> option enables the additional tracepoints. I wasn't sure
> >> while reading the help of TRACE_RCU. So here is a patch
> >> which explicitly states that this enables additional
> >> tracepoints.
> >>
> >> Apply it if you deem necessary it might be just me that
> >> thinks the description is not verbose enough.
> >>
> >> lib/Kconfig.debug | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> >> index cab7405f48d2..f8c3468ec7ef 100644
> >> --- a/lib/Kconfig.debug
> >> +++ b/lib/Kconfig.debug
> >> @@ -1429,8 +1429,8 @@ config RCU_TRACE
> >> depends on DEBUG_KERNEL
> >> select TRACE_CLOCK
> >> help
> >> - This option provides tracing in RCU which presents stats
> >> - in debugfs for debugging RCU implementation.
> >> + This option enables additional tracepoints in RCU which present
> >> + stats in debugfs for debugging RCU implementation.
> >
> > How about something like this?
> >
> > This option provides tracing in RCU which presents stats
> > in debugfs for debugging RCU implementation. It also enables
> > additional tracepoints for ftrace-style event tracing.
>
> So long as it's explicitly stated that it also enables tracepoints it's
> all fine by me. Apparently I'm not the only one who got confused. In a
> question re. CONFIG_RCU_TRACE here is what someone said on IRC:
>
> "what's tracepoints do you mean? this option enables the additional
> statistics permanently."
>
> Care to apply it with the revised wording or shall I resend?
Please see below for the current state.
Thanx, Paul
------------------------------------------------------------------------
commit a30cd69bdcb1ae12cb243e75eddd608c1798d438
Author: Nikolay Borisov <[email protected]>
Date: Thu Oct 6 05:42:39 2016 -0700
rcu: RCU_TRACE enables event tracing as well as debugfs
The commit brings the RCU_TRACE Kconfig option's help text up to date
by noting that it enables additional event tracing as well as debugfs.
Signed-off-by: Nikolay Borisov <[email protected]>
[ paulmck: Do some wordsmithing. ]
Signed-off-by: Paul E. McKenney <[email protected]>
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 2b5441812214..7f8e8f3c72ea 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1450,7 +1450,8 @@ config RCU_TRACE
select TRACE_CLOCK
help
This option provides tracing in RCU which presents stats
- in debugfs for debugging RCU implementation.
+ in debugfs for debugging RCU implementation. It also enables
+ additional tracepoints for ftrace-style event tracing.
Say Y here if you want to enable RCU tracing
Say N if you are unsure.
