From 6e43a8b173e75e9ce869a5c464bb74bbb84b30f5 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 17 Aug 2008 12:50:36 -0700 Subject: [PATCH] --- yaml --- r: 110775 b: refs/heads/master c: ded00a56e99555c3f4000ef3eebfd5fe0d574565 h: refs/heads/master i: 110773: 979830beaffd32bb86a791d87afb265f2b3e28fe 110771: bab4db4c80716b9680a8c9c81748993b8f64e221 110767: 763a56dc633bc5bad310982a362484cbfe671613 v: v3 --- [refs] | 2 +- trunk/include/linux/compiler.h | 4 +++- trunk/kernel/rcupreempt.c | 8 -------- 3 files changed, 4 insertions(+), 10 deletions(-) diff --git a/[refs] b/[refs] index 5c2cb9dfdd97..2332f327147a 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: cd95851785bcfe95fdf73689e8ecb5a1c5959231 +refs/heads/master: ded00a56e99555c3f4000ef3eebfd5fe0d574565 diff --git a/trunk/include/linux/compiler.h b/trunk/include/linux/compiler.h index c8bd2daf95ec..8322141ee480 100644 --- a/trunk/include/linux/compiler.h +++ b/trunk/include/linux/compiler.h @@ -190,7 +190,9 @@ extern void __chk_io_ptr(const volatile void __iomem *); * ACCESS_ONCE() in different C statements. * * This macro does absolutely -nothing- to prevent the CPU from reordering, - * merging, or refetching absolutely anything at any time. + * merging, or refetching absolutely anything at any time. Its main intended + * use is to mediate communication between process-level code and irq/NMI + * handlers, all running on the same CPU. */ #define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) diff --git a/trunk/kernel/rcupreempt.c b/trunk/kernel/rcupreempt.c index 27827931ca0d..ca4bbbe04aa4 100644 --- a/trunk/kernel/rcupreempt.c +++ b/trunk/kernel/rcupreempt.c @@ -58,14 +58,6 @@ #include #include -/* - * Macro that prevents the compiler from reordering accesses, but does - * absolutely -nothing- to prevent CPUs from reordering. This is used - * only to mediate communication between mainline code and hardware - * interrupt and NMI handlers. - */ -#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x)) - /* * PREEMPT_RCU data structures. */