Re: [PATCH v4 -rcu 3/4] rcu/segcblist: Add counters to segcblist datastructure

From: Joel Fernandes
Date: Tue Aug 25 2020 - 18:51:10 EST


On Tue, Aug 25, 2020 at 02:53:38PM -0700, Paul E. McKenney wrote:
> On Mon, Aug 24, 2020 at 10:48:41PM -0400, Joel Fernandes (Google) wrote:
> > Add counting of segment lengths of segmented callback list.
> >
> > This will be useful for a number of things such as knowing how big the
> > ready-to-execute segment have gotten. The immediate benefit is ability
> > to trace how the callbacks in the segmented callback list change.
> >
> > Tested by profusely reading traces when segcblist counts updated.
>
> Might I recommend a more repeatable and sustainable test methodology?
> (Sorry, couldn't resist, given that you left yourself wide open for
> that one...)

Ah, this message was from an older series :-(. I did test it with rcutorture
for many hours. But I forgot to update this commit message. :-(

I will respond to other comments soon, I am still stuck on the comment about
rcl.len and rcu_barrier interaction that you brought up in 1/4 and 2/4.

Thanks!

- Joel