Messages in this thread | | | Date | Fri, 28 Feb 2020 06:37:51 -0800 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH] Default enable RCU list lockdep debugging with PROVE_RCU |
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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 > >
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