2007-08-09 13:50:08

by Chris Snook

[permalink] [raw]
Subject: [PATCH 8/24] make atomic_read() behave consistently on i386

From: Chris Snook <[email protected]>

Make atomic_read() volatile on i386, to ensure memory is actually read
each time.

Signed-off-by: Chris Snook <[email protected]>

--- linux-2.6.23-rc2-orig/include/asm-i386/atomic.h 2007-07-08 19:32:17.000000000 -0400
+++ linux-2.6.23-rc2/include/asm-i386/atomic.h 2007-08-09 06:47:47.000000000 -0400
@@ -25,7 +25,7 @@ typedef struct { int counter; } atomic_t
*
* Atomically reads the value of @v.
*/
-#define atomic_read(v) ((v)->counter)
+#define atomic_read(v) (*(volatile int *)&(v)->counter)

/**
* atomic_set - set atomic variable