commit 7b69e8fb96fa0d85a80d261e8f8ed49f9f5565fd
author Akira Yokosawa <akiyks@gmail.com> Sun Apr 16 10:55:49 2017 +0900
committer Paul E. McKenney <paulmck@linux.vnet.ibm.com> Mon Apr 17 08:35:03 2017 -0700
tree afec022fc9f6a87d2e57f96b4f9ebc798d50c95f
parent 575c1b8ebaeb00e2a0c8944565ee5a4753ae77a1

advsync: Use READ_ONCE()/WRITE_ONCE() in sequence in 'Guarantees'

Using pseudo-asm code for sequences here also gives redundant look.
Using READ_ONCE/WRITE_ONCE() instead is a good idea.
In memory-barriers.txt, sequences corresponding to the latter part
of this section are not yet enclosed by READ_ONCE()/WRITE_ONCE(),
but memory subsystem can merge overlapping accesses even if these
directives are used.

Also use "," as delimiters in the memory access ordering lists.

Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

advsync/memorybarriers.tex

diff --git a/advsync/memorybarriers.tex b/advsync/memorybarriers.tex
index f94b113..0cd690b 100644
--- a/advsync/memorybarriers.tex
+++ b/advsync/memorybarriers.tex
@@ -1296,12 +1296,12 @@
 
 \begin{enumerate}
 \item	On any given CPU, dependent memory accesses will be issued in order,
-	with respect to itself.  This means that for:
+	with respect to itself.  This means that for a sequence (in C):
 
 \begin{minipage}[t]{\columnwidth}
 \scriptsize
 \begin{verbatim}
-Q = P; D = *Q;
+Q = READ_ONCE(P); D = READ_ONCE(*Q);
 \end{verbatim}
 \end{minipage}
 
@@ -1322,7 +1322,7 @@
 \begin{minipage}[t]{\columnwidth}
 \scriptsize
 \begin{verbatim}
-a = *X; *X = b;
+a = READ_ONCE(*X); WRITE_ONCE(*X, b);
 \end{verbatim}
 \end{minipage}
 
@@ -1341,7 +1341,7 @@
 \begin{minipage}[t]{\columnwidth}
 \scriptsize
 \begin{verbatim}
-*X = c; d = *X;
+WRITE_ONCE(*X, c); d = READ_ONCE(*X);
 \end{verbatim}
 \end{minipage}
 
@@ -1371,7 +1371,7 @@
 \begin{minipage}[t]{\columnwidth}
 \scriptsize
 \begin{verbatim}
-X = *A; Y = *B; *D = Z;
+X = READ_ONCE(*A); Y = READ_ONCE(*B); WRITE_ONCE(*D, Z);
 \end{verbatim}
 \end{minipage}
 
@@ -1395,7 +1395,7 @@
 \begin{minipage}[t]{\columnwidth}
 \scriptsize
 \begin{verbatim}
-X = *A; Y = *(A + 4);
+X = READ_ONCE(*A); Y = READ_ONCE(*(A + 4));
 \end{verbatim}
 \end{minipage}
 
@@ -1404,9 +1404,9 @@
 \begin{minipage}[t]{\columnwidth}
 \scriptsize
 \begin{verbatim}
-X = LOAD *A; Y = LOAD *(A + 4);
-Y = LOAD *(A + 4); X = LOAD *A;
-{X, Y} = LOAD {*A, *(A + 4) };
+X = LOAD *A, Y = LOAD *(A + 4)
+Y = LOAD *(A + 4), X = LOAD *A
+{X, Y} = LOAD {*A, *(A + 4) }
 \end{verbatim}
 \vspace{1pt}
 \end{minipage}
@@ -1416,7 +1416,7 @@
 \begin{minipage}[t]{\columnwidth}
 \scriptsize
 \begin{verbatim}
-*A = X; *(A + 4) = Y;
+WRITE_ONCE(*A, X); WRITE_ONCE(*(A + 4), Y);
 \end{verbatim}
 \end{minipage}
 
@@ -1425,9 +1425,9 @@
 \begin{minipage}[t]{\columnwidth}
 \scriptsize
 \begin{verbatim}
-STORE *A = X; STORE *(A + 4) = Y;
-STORE *(A + 4) = Y; STORE *A = X;
-STORE {*A, *(A + 4) } = {X, Y};
+STORE *A = X, STORE *(A + 4) = Y
+STORE *(A + 4) = Y, STORE *A = X
+STORE {*A, *(A + 4) } = {X, Y}
 \end{verbatim}
 \vspace{1pt}
 \end{minipage}
@@ -1437,7 +1437,7 @@
 \begin{minipage}[t]{\columnwidth}
 \scriptsize
 \begin{verbatim}
-*A = X; *A = Y;
+WRITE_ONCE(*A, X); WRITE_ONCE(*A, Y);
 \end{verbatim}
 \end{minipage}
 
@@ -1446,8 +1446,8 @@
 \begin{minipage}[t]{\columnwidth}
 \scriptsize
 \begin{verbatim}
-STORE *A = X; STORE *A = Y;
-STORE *A = Y;
+STORE *A = X, STORE *A = Y
+STORE *A = Y
 \end{verbatim}
 \end{minipage}