summaryrefslogtreecommitdiffstats
path: root/include
diff options
context:
space:
mode:
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2010-03-04 02:50:16 +0100
committerIngo Molnar <mingo@elte.hu>2010-03-04 12:07:33 +0100
commite6033e3b307fcfae08408e0673266db38392bda4 (patch)
treefd8d37b2aee0a1a22499297df4b748ace5166df7 /include
parentrcu: Add control variables to lockdep_rcu_dereference() diagnostics (diff)
downloadlinux-e6033e3b307fcfae08408e0673266db38392bda4.tar.xz
linux-e6033e3b307fcfae08408e0673266db38392bda4.zip
rcu: Make rcu_read_lock_sched_held() handle !PREEMPT
The rcu_read_lock_sched_held() needs to unconditionally return the value "1" in a !PREEMPT kernel, because under !PREEMPT, -all- kernel code is implicitly preempt-disabled. This patch makes this happen. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1267667418-32233-1-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include')
-rw-r--r--include/linux/rcupdate.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index c84373626336..e22960ecb71a 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -136,6 +136,7 @@ static inline int rcu_read_lock_bh_held(void)
* can prove otherwise. Note that disabling of preemption (including
* disabling irqs) counts as an RCU-sched read-side critical section.
*/
+#ifdef CONFIG_PREEMPT
static inline int rcu_read_lock_sched_held(void)
{
int lockdep_opinion = 0;
@@ -144,6 +145,12 @@ static inline int rcu_read_lock_sched_held(void)
lockdep_opinion = lock_is_held(&rcu_sched_lock_map);
return lockdep_opinion || preempt_count() != 0 || !rcu_scheduler_active;
}
+#else /* #ifdef CONFIG_PREEMPT */
+static inline int rcu_read_lock_sched_held(void)
+{
+ return 1;
+}
+#endif /* #else #ifdef CONFIG_PREEMPT */
#else /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
@@ -164,10 +171,17 @@ static inline int rcu_read_lock_bh_held(void)
return 1;
}
+#ifdef CONFIG_PREEMPT
static inline int rcu_read_lock_sched_held(void)
{
return preempt_count() != 0 || !rcu_scheduler_active;
}
+#else /* #ifdef CONFIG_PREEMPT */
+static inline int rcu_read_lock_sched_held(void)
+{
+ return 1;
+}
+#endif /* #else #ifdef CONFIG_PREEMPT */
#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */