On Tue, Nov 6, 2018 at 3:45 AM Paul E. McKenney <paulmck@xxxxxxxxxxxxx> wrote:
>
> On Sun, Nov 04, 2018 at 07:18:38PM +0800, Junchang Wang wrote:
> > Fix typos in memorder.tex.
> >
> > Signed-off-by: Junchang Wang <junchangwang@xxxxxxxxx>
>
> You know, I have no idea what litmus test I was describing in that
> paragraph, but it certainly wasn't the one in Listing 15.17. :-/
>
> I adjusted things a bit more, so please see below and let me know if
> I messed anything up.
>
> Thanx, Paul
>
> ------------------------------------------------------------------------
>
> commit 73f0f6583b154f2cd9280f321e87dcaabe6b1221
> Author: Junchang Wang <junchangwang@xxxxxxxxx>
> Date: Sun Nov 4 19:18:38 2018 +0800
>
> memorder: Fix typo
>
> Fix typos in memorder.tex, including a very confused paragraph that
> seems to be referring to some prior version of Listing 15.17.
>
> Signed-off-by: Junchang Wang <junchangwang@xxxxxxxxx>
> [ paulmck: Adjusted rewording of Listing 15.17 discussion. ]
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx>
>
> diff --git a/memorder/memorder.tex b/memorder/memorder.tex
> index 8e11e92153e0..5e74a912e15d 100644
> --- a/memorder/memorder.tex
> +++ b/memorder/memorder.tex
> @@ -1364,7 +1364,7 @@ The head pointer is \co{x1}, which initially
> references the \co{int} variable \co{y} (line~5), which is in turn
> initialized to the value $1$ (line~4).
> \co{P0()} updates head pointer \co{x1} to reference \co{x0} (line~12),
> -but only afer initializing it to $2$ (line~10) and forcing ordering
> +but only after initializing it to $2$ (line~10) and forcing ordering
> (line~11).
> \co{P1()} picks up the head pointer \co{x1} (line~21), and then loads
> the referenced value (line~22).
> @@ -2294,9 +2294,9 @@ These ordering constraints are depicted graphically in
> Figure~\ref{fig:memorder:Cumulativity}.
> Note also that cumulativity is not limited to a single step back in time.
> If there was another load from \co{x} or store to \co{x} from any thread
> -that came before the store on line~13, that prior load or store would also
> -be ordered before the store on line~32, though only if both \co{r1} and
> -\co{r2} both end up containing the address of \co{x}.
> +that came before the store on line~8, that prior load or store would also
> +be ordered before the load on line~25, though only if both \co{r1} and
> +\co{r2} both end up containing the value \co{1}.
>
Hi Paul,
Now the discussion is pretty clear to me. Thanks a lot.
Regards,
--Junchang
> In short, use of cumulative ordering operations can suppress
> non-multicopy-atomic behaviors in some situations.
>
