Commit 5a41344a authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Paul E. McKenney

srcu: Simplify __srcu_read_unlock() via this_cpu_dec()

This commit replaces disabling of preemption and decrement of a per-CPU
variable with this_cpu_dec(), which avoids preemption disabling on x86
and shortens the code on all platforms.
Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
parent 0351096e
...@@ -321,10 +321,8 @@ EXPORT_SYMBOL_GPL(__srcu_read_lock); ...@@ -321,10 +321,8 @@ EXPORT_SYMBOL_GPL(__srcu_read_lock);
*/ */
void __srcu_read_unlock(struct srcu_struct *sp, int idx) void __srcu_read_unlock(struct srcu_struct *sp, int idx)
{ {
preempt_disable();
smp_mb(); /* C */ /* Avoid leaking the critical section. */ smp_mb(); /* C */ /* Avoid leaking the critical section. */
ACCESS_ONCE(this_cpu_ptr(sp->per_cpu_ref)->c[idx]) -= 1; this_cpu_dec(sp->per_cpu_ref->c[idx]);
preempt_enable();
} }
EXPORT_SYMBOL_GPL(__srcu_read_unlock); EXPORT_SYMBOL_GPL(__srcu_read_unlock);
......
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