Here is a more recent version of the patch. It has more accurate comments.
- [PATCH v2 tip/core/rcu 1/3] srcu: Implement more-efficien... Lance Roy
- [PATCH] SRCU: More efficient reader counts. Lance Roy
- Re: [PATCH] SRCU: More efficient reader counts. Paul E. McKenney
- Re: [PATCH] SRCU: More efficient reader coun... Lance Roy
- [PATCH] srcu: Implement more-efficient r... Lance Roy
- Re: [PATCH] srcu: Implement more-ef... Paul E. McKenney
- Re: [PATCH] srcu: Implement mor... Lance Roy
- Re: [PATCH] srcu: Implement... Paul E. McKenney
- Re: [PATCH] srcu: Implement... Lance Roy
- Re: [PATCH] srcu: Implement... Paul E. McKenney