Commit-ID: dc87917501e324701dbfb249def44054b5220187 Gitweb: http://git.kernel.org/tip/dc87917501e324701dbfb249def44054b5220187 Author: Lai Jiangshan <laijs@xxxxxxxxxxxxxx> AuthorDate: Tue, 6 Mar 2012 17:57:34 +0800 Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> CommitDate: Mon, 30 Apr 2012 10:48:24 -0700 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 <laijs@xxxxxxxxxxxxxx> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> --- kernel/srcu.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/kernel/srcu.c b/kernel/srcu.c index e0139a2..a43211c 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; } /** -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html