Re: [PATCH v2 0/9] Remove spin_unlock_wait()

From: Paul E. McKenney
Date: Fri Jul 07 2017 - 10:43:42 EST


On Fri, Jul 07, 2017 at 10:31:28AM +0200, Ingo Molnar wrote:

[ . . . ]

> In fact I'd argue that any future high performance spin_unlock_wait() user is
> probably better off open coding the unlock-wait poll loop (and possibly thinking
> hard about eliminating it altogether). If such patterns pop up in the kernel we
> can think about consolidating them into a single read-only primitive again.

I would like any reintroduction to include a header comment saying exactly
what the consolidated primitive actually does and does not do. ;-)

> I.e. I think the proposed changes are doing no harm, and the unavailability of a
> generic primitive does not hinder future optimizations either in any significant
> fashion.

I will have a v3 with updated comments from Manfred. Thoughts on when/where
to push this?

The reason I ask is if this does not go in during this merge window, I need
to fix the header comment on spin_unlock_wait().

Thanx, Paul