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authorBoqun Feng <boqun.feng@gmail.com>2016-03-23 23:11:48 +0800
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2016-03-31 13:34:50 -0700
commit293e2421fe25839500207eda123cc4475f8d17b8 (patch)
treeca4768d1bc3b351394a2a3003c7cc98db923197a /kernel/rcu
parent8c7c4829a81c1838f18c12ce5a3a5c29a08bf0a8 (diff)
downloadlinux-sh-293e2421fe25839500207eda123cc4475f8d17b8.tar.gz
rcu: Remove superfluous versions of rcu_read_lock_sched_held()
Currently, we have four versions of rcu_read_lock_sched_held(), depending on the combined choices on PREEMPT_COUNT and DEBUG_LOCK_ALLOC. However, there is an existing function preemptible() that already distinguishes between the PREEMPT_COUNT=y and PREEMPT_COUNT=n cases, and allows these four implementations to be consolidated down to two. This commit therefore uses preemptible() to achieve this consolidation. Note that there could be a small performance regression in the case of CONFIG_DEBUG_LOCK_ALLOC=y && PREEMPT_COUNT=n. However, given the overhead associated with CONFIG_DEBUG_LOCK_ALLOC=y, this should be down in the noise. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/update.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index ca828b41c938..3ccdc8eebc5a 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -67,7 +67,7 @@ static int rcu_normal_after_boot;
module_param(rcu_normal_after_boot, int, 0);
#endif /* #ifndef CONFIG_TINY_RCU */
-#if defined(CONFIG_DEBUG_LOCK_ALLOC) && defined(CONFIG_PREEMPT_COUNT)
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
/**
* rcu_read_lock_sched_held() - might we be in RCU-sched read-side critical section?
*
@@ -111,7 +111,7 @@ int rcu_read_lock_sched_held(void)
return 0;
if (debug_locks)
lockdep_opinion = lock_is_held(&rcu_sched_lock_map);
- return lockdep_opinion || preempt_count() != 0 || irqs_disabled();
+ return lockdep_opinion || !preemptible();
}
EXPORT_SYMBOL(rcu_read_lock_sched_held);
#endif