[PATCH 1/1] doc: Update control-dependencies section of memory-barriers.txt

[pierre Kuo]

for below example, if MAX is defined to be 1, then the compiler knows (Q
% MAX) is equal to zero.
so compiler will transform the "else" part of code.

        q = READ_ONCE(a);
        if (q % MAX) {
                WRITE_ONCE(b, 1);
                do_something();
        } else {
                WRITE_ONCE(b, 2);
                do_something_else();
        }

So we modify the original document as below:

        q = READ_ONCE(a);
-       WRITE_ONCE(b, 1);
+       WRITE_ONCE(b, 2);
        do_something_else();

Signed-off-by: pierre Kuo <vichy....@gmail.com>
---
 Documentation/memory-barriers.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/memory-barriers.txt 
b/Documentation/memory-barriers.txt
index d2b0a8d..08329cb 100644
--- a/Documentation/memory-barriers.txt
+++ b/Documentation/memory-barriers.txt
@@ -768,7 +768,7 @@ equal to zero, in which case the compiler is within its 
rights to
 transform the above code into the following:
 
        q = READ_ONCE(a);
-       WRITE_ONCE(b, 1);
+       WRITE_ONCE(b, 2);
        do_something_else();
 
 Given this transformation, the CPU is not required to respect the ordering
-- 
1.9.1

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