Re: [PATCH v14 09/12] unwind deferred: Use SRCU unwind_deferred_task_work()

[Steven Rostedt]

On Wed, 16 Jul 2025 21:43:47 -0700
"Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote:

> > +DEFINE_LOCK_GUARD_1(srcu_lite, struct srcu_struct,  
> 
> You need srcu_fast because srcu_lite is being removed.  They are quite
> similar, but srcu_fast is faster and is NMI-safe.  (This last might or
> might not matter here.)
> 
> See https://lore.kernel.org/all/20250716225418.3014815-3-paulmck@xxxxxxxxxx/
> for a srcu_fast_notrace, so something like this:

Yeah, I already saw that patch.

> 
> DEFINE_LOCK_GUARD_1(srcu_fast, struct srcu_struct,
> 		    _T->scp = srcu_read_lock_fast(_T->lock),
> 		    srcu_read_unlock_fast(_T->lock, _T->scp),
> 		    struct srcu_ctr __percpu *scp)
> 
> Other than that, it looks plausible.

Using srcu_lite or srcu_fast is an optimization here. And since I saw you
adding the guard for srcu_fast in that other thread, I'll just use normal
SRCU here for this series, and in the future we could convert it over to
srcu_fast.

Thanks!

-- Steve