On Mon, Jul 21, 2025 at 09:24:31AM -0700, Paul E. McKenney wrote:
> This commit adds no-trace variants of the srcu_read_lock_fast() and
> srcu_read_unlock_fast() functions for tracing use.
>
> Signed-off-by: Paul E. McKenney <paul...@kernel.org>
> Cc: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
> Cc: Steven Rostedt <rost...@goodmis.org>
> Cc: Sebastian Andrzej Siewior <bige...@linutronix.de>
> ---
> include/linux/srcu.h | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/include/linux/srcu.h b/include/linux/srcu.h
> index 478c73d067f7d..7a692bf8f99b9 100644
> --- a/include/linux/srcu.h
> +++ b/include/linux/srcu.h
> @@ -282,6 +282,20 @@ static inline struct srcu_ctr __percpu
> *srcu_read_lock_fast(struct srcu_struct *
> return retval;
> }
>
> +/*
> + * Used by tracing, cannot be traced and cannot call lockdep.
> + * See srcu_read_lock_fast() for more information.
> + */
> +static inline struct srcu_ctr __percpu *srcu_read_lock_fast_notrace(struct
> srcu_struct *ssp)
> + __acquires(ssp)
Should these also be marked with 'notrace' attribute?
I am not sure what the precedent is, I do see a few examples of 'notrace' and
'inline' in the same function signature though.
Other than that one nit:
Reviewed-by: Joel Fernandes <joelagn...@nvidia.com>
thanks,
- Joel
> +{
> + struct srcu_ctr __percpu *retval;
> +
> + srcu_check_read_flavor_force(ssp, SRCU_READ_FLAVOR_FAST);
> + retval = __srcu_read_lock_fast(ssp);
> + return retval;
> +}
> +
> /**
> * srcu_down_read_fast - register a new reader for an SRCU-protected
> structure.
> * @ssp: srcu_struct in which to register the new reader.
> @@ -394,6 +408,17 @@ static inline void srcu_read_unlock_fast(struct
> srcu_struct *ssp, struct srcu_ct
> RCU_LOCKDEP_WARN(!rcu_is_watching(), "RCU must be watching
> srcu_read_unlock_fast().");
> }
>
> +/*
> + * Used by tracing, cannot be traced and cannot call lockdep.
> + * See srcu_read_unlock_fast() for more information.
> + */
> +static inline void srcu_read_unlock_fast_notrace(struct srcu_struct *ssp,
> + struct srcu_ctr __percpu *scp)
> __releases(ssp)
> +{
> + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_FAST);
> + __srcu_read_unlock_fast(ssp, scp);
> +}
> +
> /**
> * srcu_up_read_fast - unregister a old reader from an SRCU-protected
> structure.
> * @ssp: srcu_struct in which to unregister the old reader.
> --
> 2.40.1
>
