Re: [PATCH tip/core/rcu 24/24] rcu: Conditionally compile RCU's eqs warnings

From: Paul E. McKenney
Date: Tue Jun 30 2015 - 12:58:06 EST


On Mon, Jun 29, 2015 at 10:58:51PM +0200, Geert Uytterhoeven wrote:
> Hi Paul,
>
> On Mon, Jun 29, 2015 at 10:55 PM, Paul E. McKenney
> <paulmck@xxxxxxxxxxxxxxxxxx> wrote:
> > On Mon, Jun 29, 2015 at 11:39:13AM +0200, Geert Uytterhoeven wrote:
> >> On Wed, May 13, 2015 at 12:30 AM, Paul E. McKenney
> >> <paulmck@xxxxxxxxxxxxxxxxxx> wrote:
> >> > --- a/lib/Kconfig.debug
> >> > +++ b/lib/Kconfig.debug
> >> > @@ -1373,6 +1373,17 @@ config RCU_TRACE
> >> > Say Y here if you want to enable RCU tracing
> >> > Say N if you are unsure.
> >> >
> >> > +config RCU_EQS_DEBUG
> >> > + bool "Use this when adding any sort of NO_HZ support to your arch"
> >>
> >> This sounds a bit fuzzy. Can you please provide a better one-line description?
> >> Thanks!
> >
> > So the point of this Kconfig option is to provide WARN_ON()s that catch
> > bug such as telling RCU that a given CPU entered idle, but failing to
> > tell RCU when that CPU later leaves idle. So how about this?
> >
> > + bool "Provide debugging asserts for adding NO_HZ support to an arch"
>
> Much better, thanks!

Queued the following for v4.3, thank you!

Thanx, Paul

------------------------------------------------------------------------

commit bb651123a8ed43543f3ec8ac84e6152a866e2639
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Date: Tue Jun 30 09:56:31 2015 -0700

rcu: Clarify CONFIG_RCU_EQS_DEBUG help text

Reported-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 6be521990d61..80efaade5e59 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1360,7 +1360,7 @@ config RCU_TRACE
Say N if you are unsure.

config RCU_EQS_DEBUG
- bool "Use this when adding any sort of NO_HZ support to your arch"
+ bool "Provide debugging asserts for adding NO_HZ support to an arch"
depends on DEBUG_KERNEL
help
This option provides consistency checks in RCU's handling of

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