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| author | Boqun Feng <boqun.feng@gmail.com> | 2016-03-23 23:11:48 +0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2016-03-31 13:34:50 -0700 |
| commit | 293e2421fe25839500207eda123cc4475f8d17b8 (patch) | |
| tree | ca4768d1bc3b351394a2a3003c7cc98db923197a /kernel/rcu | |
| parent | 8c7c4829a81c1838f18c12ce5a3a5c29a08bf0a8 (diff) | |
| download | linux-stable-293e2421fe25839500207eda123cc4475f8d17b8.tar.gz linux-stable-293e2421fe25839500207eda123cc4475f8d17b8.tar.bz2 linux-stable-293e2421fe25839500207eda123cc4475f8d17b8.zip | |
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.c | 4 |
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 |