[PATCH] sched/topology: Remove redundant variable and fix incorrect type in build_sched_domains

From: K Prateek Nayak
Date: Fri Feb 18 2022 - 11:27:59 EST


While investigating the sparse warning reported by the LKP bot [1],
observed that we have a redundant variable "top" in the function
build_sched_domains that was introduced in the recent commit
e496132ebedd ("sched/fair: Adjust the allowed NUMA imbalance when
SD_NUMA spans multiple LLCs")

The existing variable "sd" suffices which allows us to remove the
redundant variable "top" while annotating the other variable "top_p"
with the "__rcu" annotation to silence the sparse warning.

[1] https://lore.kernel.org/lkml/202202170853.9vofgC3O-lkp@xxxxxxxxx/

Fixes: e496132ebedd ("sched/fair: Adjust the allowed NUMA imbalance when SD_NUMA spans multiple LLCs")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: K Prateek Nayak <kprateek.nayak@xxxxxxx>
---
kernel/sched/topology.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index e6cd55951304..4b757fb8f661 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -2255,7 +2255,7 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att

if (!(sd->flags & SD_SHARE_PKG_RESOURCES) && child &&
(child->flags & SD_SHARE_PKG_RESOURCES)) {
- struct sched_domain *top, *top_p;
+ struct sched_domain __rcu *top_p;
unsigned int nr_llcs;

/*
@@ -2280,11 +2280,9 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att
sd->imb_numa_nr = imb;

/* Set span based on the first NUMA domain. */
- top = sd;
- top_p = top->parent;
+ top_p = sd->parent;
while (top_p && !(top_p->flags & SD_NUMA)) {
- top = top->parent;
- top_p = top->parent;
+ top_p = top_p->parent;
}
imb_span = top_p ? top_p->span_weight : sd->span_weight;
} else {
--
2.25.1