lkml.org 
[lkml]   [2020]   [Feb]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] Default enable RCU list lockdep debugging with PROVE_RCU
On Fri, Feb 28, 2020 at 09:21:22AM -0500, Joel Fernandes wrote:
> On Fri, Feb 28, 2020 at 02:54:51PM +0530, madhuparnabhowmik10@gmail.com wrote:
> > From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
> >
> > This patch default enables CONFIG_PROVE_RCU_LIST option with
> > CONFIG_PROVE_RCU for RCU list lockdep debugging.
> >
> > With this change, RCU list lockdep debugging will be default
> > enabled in CONFIG_PROVE_RCU=y kernels.
> >
> > Most of the RCU users (in core kernel/, drivers/, and net/
> > subsystem) have already been modified to include lockdep
> > expressions hence RCU list debugging can be enabled by
> > default.
> >
> > However, there are still chances of enountering
> > false-positive lockdep splats because not everything is converted,
> > in case RCU list primitives are used in non-RCU read-side critical
> > section but under the protection of a lock. It would be okay to
> > have a few false-positives, as long as bugs are identified, since this
> > patch only affects debugging kernels.
> >
> > Co-developed-by: Amol Grover <frextrite@gmail.com>
> > Signed-off-by: Amol Grover <frextrite@gmail.com>
> > Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>
>
> Acked-by: Joel Fernandes (Google) <joel@joelfernandes.org>

Queued, thank you both!

Thanx, Paul

> thanks,
>
> - Joel
>
> > ---
> > kernel/rcu/Kconfig.debug | 11 +++--------
> > 1 file changed, 3 insertions(+), 8 deletions(-)
> >
> > diff --git a/kernel/rcu/Kconfig.debug b/kernel/rcu/Kconfig.debug
> > index 4aa02eee8f6c..ec4bb6c09048 100644
> > --- a/kernel/rcu/Kconfig.debug
> > +++ b/kernel/rcu/Kconfig.debug
> > @@ -9,15 +9,10 @@ config PROVE_RCU
> > def_bool PROVE_LOCKING
> >
> > config PROVE_RCU_LIST
> > - bool "RCU list lockdep debugging"
> > - depends on PROVE_RCU && RCU_EXPERT
> > - default n
> > + def_bool PROVE_RCU
> > help
> > - Enable RCU lockdep checking for list usages. By default it is
> > - turned off since there are several list RCU users that still
> > - need to be converted to pass a lockdep expression. To prevent
> > - false-positive splats, we keep it default disabled but once all
> > - users are converted, we can remove this config option.
> > + Enable RCU lockdep checking for list usages. It is default
> > + enabled with CONFIG_PROVE_RCU.
> >
> > config TORTURE_TEST
> > tristate
> > --
> > 2.17.1
> >

\
 
 \ /
  Last update: 2020-02-28 15:37    [W:0.142 / U:0.176 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site