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

[Paul E. McKenney]

On Thu, Jul 17, 2025 at 12:38:35PM -0400, Steven Rostedt wrote:
> On Thu, 17 Jul 2025 09:27:34 -0700
> "Paul E. McKenney" <paulmck@xxxxxxxxxx> wrote:
> 
> > > Two, I'm still grasping at the concept of srcu_fast (and srcu_lite for
> > > that matter), where I rather be slow and safe than optimize and be
> > > unsafe. The code where this is used may be faulting in user space
> > > memory, so it doesn't need the micro-optimizations now.  
> > 
> > Straight-up SRCU and guard(srcu), then?  Both are already in mainline.
> > 
> > Or are those read-side smp_mb() calls a no-go for this code?
> 
> As I stated, the read-side is likely going to be faulting in user space
> memory. I don't think one or two smp_mb() will really make much of a
> difference ;-)
> 
> It's not urgent. If it can be switched to srcu_fast, we can do it later.

Very good, we will continue with our removal of SRCU-lite, and I might
as well add guard(srcu_fast) in my current series.

							Thanx, Paul