Subsection Multicopy Atomicity is ahead of Subsection Hardware Specifics where implementation detail of multicopy atomicity in mainstream architectures is presented. So we add (1) a brief description of the use of multicopy atomicity in representative architectures and (2) a reference to Table Summary of Memory Ordering, in subsection Multicopy Atomicity. The description is borrowed from a nice discussion with Paul, which can be found at https://www.spinics.net/lists/perfbook/msg01952.html. Signed-off-by: Junchang Wang <junchangwang@xxxxxxxxx> --- memorder/memorder.tex | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/memorder/memorder.tex b/memorder/memorder.tex index fba49b7..69ce196 100644 --- a/memorder/memorder.tex +++ b/memorder/memorder.tex @@ -1901,7 +1901,11 @@ Most CPU vendors interested in providing multicopy atomicity have therefore instead provided the slightly weaker \emph{other-multicopy atomicity}~\cite[Section B2.3]{ARMv8A:2017}, which excludes the CPU doing a given store from the requirement that all -CPUs agree on the order of all stores. +CPUs agree on the order of all stores.\footnote{ + As of late 2018, ARMv8 and x86 provide other-multicopy atomicity, + IBM mainframe provides fully multicopy atomicity, and PPC does + not provide multicopy atomicity at all. More detail is shown in + Figure~\ref{tab:memorder:Summary of Memory Ordering}.} This means that if only a subset of CPUs are doing stores, the other CPUs will agree on the order of stores, hence the ``other'' in ``other-multicopy atomicity''. -- 2.7.4
