Re: [PATCH v5 06/13] lockdep: Implement crossrelease feature

Peter Zijlstra
2017-03-02T14:31:43Z

On Wed, Jan 18, 2017 at 10:17:32PM +0900, Byungchul Park wrote:
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index a6c8db1..7890661 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -1042,6 +1042,19 @@ config DEBUG_LOCK_ALLOC
> spin_lock_init()/mutex_init()/etc., or whether there is any lock
> held during task exit.
>
> +config LOCKDEP_CROSSRELEASE
> + bool "Lock debugging: make lockdep work for crosslocks"
> + select LOCKDEP
> + select TRACE_IRQFLAGS
> + default n
> + help
> + This makes lockdep work for crosslock which is a lock allowed to
> + be released in a different context from the acquisition context.
> + Normally a lock must be released in the context acquiring the lock.
> + However, relexing this constraint helps synchronization primitives
> + such as page locks or completions can use the lock correctness
> + detector, lockdep.
> +
> config PROVE_LOCKING
> bool "Lock debugging: prove locking correctness"
> depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT

Does CROSSRELEASE && !PROVE_LOCKING make any sense?