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author | Lai Jiangshan <laijs@cn.fujitsu.com> | 2012-11-29 12:46:02 +0400 |
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committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-02-08 03:06:25 +0400 |
commit | 5a41344a3d83ef2c08e40bfce1efa5795def9b82 (patch) | |
tree | 123d0fa065a35bb7de384edb5e753ec28beee7b0 | |
parent | 0351096eb0584ba927a00a37e18be7af135250c3 (diff) | |
download | linux-5a41344a3d83ef2c08e40bfce1efa5795def9b82.tar.xz |
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: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
-rw-r--r-- | kernel/srcu.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/kernel/srcu.c b/kernel/srcu.c index 2b859828cdc3..c9d003bc6c49 100644 --- a/kernel/srcu.c +++ b/kernel/srcu.c @@ -321,10 +321,8 @@ EXPORT_SYMBOL_GPL(__srcu_read_lock); */ void __srcu_read_unlock(struct srcu_struct *sp, int idx) { - preempt_disable(); smp_mb(); /* C */ /* Avoid leaking the critical section. */ - ACCESS_ONCE(this_cpu_ptr(sp->per_cpu_ref)->c[idx]) -= 1; - preempt_enable(); + this_cpu_dec(sp->per_cpu_ref->c[idx]); } EXPORT_SYMBOL_GPL(__srcu_read_unlock); |