Commit 65f95ff2 authored Feb 22, 2016 by SeongJae Park Committed by Paul E. McKenney Mar 14, 2016

documentation: Clarify compiler store-fusion example



The compiler store-fusion example in memory-barriers.txt uses a C
comment to represent arbitrary code that does not update a given
variable.  Unfortunately, someone could reasonably interpret the
comment as instead referring to the following line of code.  This
commit therefore replaces the comment with a string that more
clearly represents the arbitrary code.

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

parent f36fe1e7

Documentation/memory-barriers.txt

+2 −2

Original line number	Diff line number	Diff line
		@@ -1550,7 +1550,7 @@ of optimizations:
		the following:

		a = 0;
		/* Code that does not store to variable a. */
		... Code that does not store to variable a ...
		a = 0;

		The compiler sees that the value of variable 'a' is already zero, so
		@@ -1562,7 +1562,7 @@ of optimizations:
		wrong guess:

		WRITE_ONCE(a, 0);
		/* Code that does not store to variable a. */
		... Code that does not store to variable a ...
		WRITE_ONCE(a, 0);

		(*) The compiler is within its rights to reorder memory accesses unless