markers: use rcu_barrier_sched() and call_rcu_sched()

rcu_barrier_sched() and call_rcu_sched() were introduced in 2.6.26 for the
Markers.  Change the marker code to use them.

It can be seen as a fix since the marker code was using an ugly,
temporary, #ifdef hack to work around CONFIG_PREEMPT_RCU.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Paul McKenney <paulmck@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 17 deletions

diff --git a/kernel/marker.c b/kernel/marker.c
index 1abfb923b761..971da5317903 100644
--- a/kernel/marker.c
+++ b/kernel/marker.c
@@ -441,7 +441,7 @@ static int remove_marker(const char *name)
         hlist_del(&e->hlist);
         /* Make sure the call_rcu has been executed */
         if (e->rcu_pending)
-                rcu_barrier();
+                rcu_barrier_sched();
         kfree(e);
         return 0;
 }
@@ -476,7 +476,7 @@ static int marker_set_format(struct marker_entry **entry, const char *format)
         hlist_del(&(*entry)->hlist);
         /* Make sure the call_rcu has been executed */
         if ((*entry)->rcu_pending)
-                rcu_barrier();
+                rcu_barrier_sched();
         kfree(*entry);
         *entry = e;
         trace_mark(core_marker_format, "name %s format %s",
@@ -655,7 +655,7 @@ int marker_probe_register(const char *name, const char *format,
          * make sure it's executed now.
          */
         if (entry->rcu_pending)
-                rcu_barrier();
+                rcu_barrier_sched();
         old = marker_entry_add_probe(entry, probe, probe_private);
         if (IS_ERR(old)) {
                 ret = PTR_ERR(old);
@@ -670,10 +670,7 @@ int marker_probe_register(const char *name, const char *format,
         entry->rcu_pending = 1;
         /* write rcu_pending before calling the RCU callback */
         smp_wmb();
-#ifdef CONFIG_PREEMPT_RCU
-        synchronize_sched();    /* Until we have the call_rcu_sched() */
-#endif
-        call_rcu(&entry->rcu, free_old_closure);
+        call_rcu_sched(&entry->rcu, free_old_closure);
 end:
         mutex_unlock(&markers_mutex);
         return ret;
@@ -704,7 +701,7 @@ int marker_probe_unregister(const char *name,
         if (!entry)
                 goto end;
         if (entry->rcu_pending)
-                rcu_barrier();
+                rcu_barrier_sched();
         old = marker_entry_remove_probe(entry, probe, probe_private);
         mutex_unlock(&markers_mutex);
         marker_update_probes();         /* may update entry */
@@ -716,10 +713,7 @@ int marker_probe_unregister(const char *name,
         entry->rcu_pending = 1;
         /* write rcu_pending before calling the RCU callback */
         smp_wmb();
-#ifdef CONFIG_PREEMPT_RCU
-        synchronize_sched();    /* Until we have the call_rcu_sched() */
-#endif
-        call_rcu(&entry->rcu, free_old_closure);
+        call_rcu_sched(&entry->rcu, free_old_closure);
         remove_marker(name);    /* Ignore busy error message */
         ret = 0;
 end:
@@ -786,7 +780,7 @@ int marker_probe_unregister_private_data(marker_probe_func *probe,
                 goto end;
         }
         if (entry->rcu_pending)
-                rcu_barrier();
+                rcu_barrier_sched();
         old = marker_entry_remove_probe(entry, NULL, probe_private);
         mutex_unlock(&markers_mutex);
         marker_update_probes();         /* may update entry */
@@ -797,10 +791,7 @@ int marker_probe_unregister_private_data(marker_probe_func *probe,
         entry->rcu_pending = 1;
         /* write rcu_pending before calling the RCU callback */
         smp_wmb();
-#ifdef CONFIG_PREEMPT_RCU
-        synchronize_sched();    /* Until we have the call_rcu_sched() */
-#endif
-        call_rcu(&entry->rcu, free_old_closure);
+        call_rcu_sched(&entry->rcu, free_old_closure);
         remove_marker(entry->name);     /* Ignore busy error message */
 end:
         mutex_unlock(&markers_mutex);