Re: [PATCH] locking: Add __lockfunc to slow path functions

[Waiman Long <longman@redhat.com>]

On 8/8/22 13:59, Namhyung Kim wrote:
> So that we can skip the functions in the perf lock contention and other
> places like /proc/PID/wchan.
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
>   kernel/locking/qrwlock.c   | 4 ++--
>   kernel/locking/qspinlock.c | 2 +-
>   2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/locking/qrwlock.c b/kernel/locking/qrwlock.c
> index 2e1600906c9f..d2ef312a8611 100644
> --- a/kernel/locking/qrwlock.c
> +++ b/kernel/locking/qrwlock.c
> @@ -18,7 +18,7 @@
>    * queued_read_lock_slowpath - acquire read lock of a queued rwlock
>    * @lock: Pointer to queued rwlock structure
>    */
> -void queued_read_lock_slowpath(struct qrwlock *lock)
> +void __lockfunc queued_read_lock_slowpath(struct qrwlock *lock)
>   {
>   	/*
>   	 * Readers come here when they cannot get the lock without waiting
> @@ -63,7 +63,7 @@ EXPORT_SYMBOL(queued_read_lock_slowpath);
>    * queued_write_lock_slowpath - acquire write lock of a queued rwlock
>    * @lock : Pointer to queued rwlock structure
>    */
> -void queued_write_lock_slowpath(struct qrwlock *lock)
> +void __lockfunc queued_write_lock_slowpath(struct qrwlock *lock)
>   {
>   	int cnts;
>   
> diff --git a/kernel/locking/qspinlock.c b/kernel/locking/qspinlock.c
> index 65a9a10caa6f..2b23378775fe 100644
> --- a/kernel/locking/qspinlock.c
> +++ b/kernel/locking/qspinlock.c
> @@ -313,7 +313,7 @@ static __always_inline u32  __pv_wait_head_or_lock(struct qspinlock *lock,
>    * contended             :    (*,x,y) +--> (*,0,0) ---> (*,0,1) -'  :
>    *   queue               :         ^--'                             :
>    */
> -void queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
> +void __lockfunc queued_spin_lock_slowpath(struct qspinlock *lock, u32 val)
>   {
>   	struct mcs_spinlock *prev, *next, *node;
>   	u32 old, tail;


For completeness, I think you should also add it to the 
__pv_queued_spin_unlock() and __pv_queued_spin_unlock_slowpath() 
function in kernel/locking/qspinlock_paravirt.h. Perhaps even the 
assembly code in arch/x86/include/asm/qspinlock_paravirt.h.

Cheers,
Longman