From dc87917501e324701dbfb249def44054b5220187 Mon Sep 17 00:00:00 2001 From: Lai Jiangshan Date: Tue, 6 Mar 2012 17:57:34 +0800 Subject: rcu: Improve srcu_readers_active_idx()'s cache locality Expand the calls to srcu_readers_active_idx() from srcu_readers_active() inline. This change improves cache locality by interating over the CPUs once rather than twice. Signed-off-by: Lai Jiangshan Signed-off-by: Paul E. McKenney --- kernel/srcu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/kernel/srcu.c b/kernel/srcu.c index e0139a274856..a43211c92863 100644 --- a/kernel/srcu.c +++ b/kernel/srcu.c @@ -193,7 +193,14 @@ static bool srcu_readers_active_idx_check(struct srcu_struct *sp, int idx) */ static int srcu_readers_active(struct srcu_struct *sp) { - return srcu_readers_active_idx(sp, 0) + srcu_readers_active_idx(sp, 1); + int cpu; + unsigned long sum = 0; + + for_each_possible_cpu(cpu) { + sum += ACCESS_ONCE(per_cpu_ptr(sp->per_cpu_ref, cpu)->c[0]); + sum += ACCESS_ONCE(per_cpu_ptr(sp->per_cpu_ref, cpu)->c[1]); + } + return sum; } /** -- cgit v1.2.3