[PATCH 1/2] sched/topology: pre-compute topology_span_sane() loop params

Yury Norov posted 2 patches 1 year, 6 months ago
There is a newer version of this series
[PATCH 1/2] sched/topology: pre-compute topology_span_sane() loop params
Posted by Yury Norov 1 year, 6 months ago
tl->mask() is called inside the loop with the same parameters more than
once. We can pre-calculate it.

Reviewed-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
 kernel/sched/topology.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 76504b776d03..8af3b48da458 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -2353,12 +2353,15 @@ static struct sched_domain *build_sched_domain(struct sched_domain_topology_leve
 static bool topology_span_sane(struct sched_domain_topology_level *tl,
 			      const struct cpumask *cpu_map, int cpu)
 {
+	const struct cpumask *mi, *mc;
 	int i = cpu + 1;
 
 	/* NUMA levels are allowed to overlap */
 	if (tl->flags & SDTL_OVERLAP)
 		return true;
 
+	mc = tl->mask(cpu);
+
 	/*
 	 * Non-NUMA levels cannot partially overlap - they must be either
 	 * completely equal or completely disjoint. Otherwise we can end up
@@ -2366,14 +2369,15 @@ static bool topology_span_sane(struct sched_domain_topology_level *tl,
 	 * breaks the linking done for an earlier span.
 	 */
 	for_each_cpu_from(i, cpu_map) {
+		mi = tl->mask(i);
+
 		/*
 		 * We should 'and' all those masks with 'cpu_map' to exactly
 		 * match the topology we're about to build, but that can only
 		 * remove CPUs, which only lessens our ability to detect
 		 * overlaps
 		 */
-		if (!cpumask_equal(tl->mask(cpu), tl->mask(i)) &&
-		    cpumask_intersects(tl->mask(cpu), tl->mask(i)))
+		if (!cpumask_equal(mc, mi) && cpumask_intersects(mc, mi))
 			return false;
 	}
 
-- 
2.43.0