markers: remove ACCESS_ONCE

As Paul pointed out, the ACCESS_ONCE are not needed because we already have
the explicit surrounding memory barriers.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Mike Mason <mmlnx@us.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: David Smith <dsmith@redhat.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Adrian Bunk <adrian.bunk@movial.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/marker.c b/kernel/marker.c
index ccae1d1..041c33e 100644 (file)
--- a/kernel/marker.c
+++ b/kernel/marker.c
@@ -109,13 +109,13 @@ void marker_probe_cb(const struct marker *mdata, void *call_private,
         * modules and they insure RCU read coherency.
         */
        preempt_disable();
-       ptype = ACCESS_ONCE(mdata->ptype);
+       ptype = mdata->ptype;
        if (likely(!ptype)) {
                marker_probe_func *func;
                /* Must read the ptype before ptr. They are not data dependant,
                 * so we put an explicit smp_rmb() here. */
                smp_rmb();
-               func = ACCESS_ONCE(mdata->single.func);
+               func = mdata->single.func;
                /* Must read the ptr before private data. They are not data
                 * dependant, so we put an explicit smp_rmb() here. */
                smp_rmb();
@@ -133,7 +133,7 @@ void marker_probe_cb(const struct marker *mdata, void *call_private,
                 * in the fast path, so put the explicit barrier here.
                 */
                smp_read_barrier_depends();
-               multi = ACCESS_ONCE(mdata->multi);
+               multi = mdata->multi;
                for (i = 0; multi[i].func; i++) {
                        va_start(args, fmt);
                        multi[i].func(multi[i].probe_private, call_private, fmt,
@@ -161,13 +161,13 @@ void marker_probe_cb_noarg(const struct marker *mdata,
        char ptype;
 
        preempt_disable();
-       ptype = ACCESS_ONCE(mdata->ptype);
+       ptype = mdata->ptype;
        if (likely(!ptype)) {
                marker_probe_func *func;
                /* Must read the ptype before ptr. They are not data dependant,
                 * so we put an explicit smp_rmb() here. */
                smp_rmb();
-               func = ACCESS_ONCE(mdata->single.func);
+               func = mdata->single.func;
                /* Must read the ptr before private data. They are not data
                 * dependant, so we put an explicit smp_rmb() here. */
                smp_rmb();
@@ -183,7 +183,7 @@ void marker_probe_cb_noarg(const struct marker *mdata,
                 * in the fast path, so put the explicit barrier here.
                 */
                smp_read_barrier_depends();
-               multi = ACCESS_ONCE(mdata->multi);
+               multi = mdata->multi;
                for (i = 0; multi[i].func; i++)
                        multi[i].func(multi[i].probe_private, call_private, fmt,
                                &args);