[PATCH 2/4] lib/group_cpus: relax atomicity requirement in grp_spread_init_one()

From: Yury Norov
Date: Wed Nov 01 2023 - 18:58:35 EST


Because the function is called with cpus_read_lock() held, all the masks
involved are stabilized, and thus any extra atomicity is not required.

Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
---
lib/group_cpus.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/lib/group_cpus.c b/lib/group_cpus.c
index aa3f6815bb12..b1e7d9cc9da9 100644
--- a/lib/group_cpus.c
+++ b/lib/group_cpus.c
@@ -24,8 +24,8 @@ static void grp_spread_init_one(struct cpumask *irqmsk, struct cpumask *nmsk,
if (cpu >= nr_cpu_ids)
return;

- cpumask_clear_cpu(cpu, nmsk);
- cpumask_set_cpu(cpu, irqmsk);
+ __cpumask_clear_cpu(cpu, nmsk);
+ __cpumask_set_cpu(cpu, irqmsk);
cpus_per_grp--;

/* If the cpu has siblings, use them first */
@@ -34,9 +34,8 @@ static void grp_spread_init_one(struct cpumask *irqmsk, struct cpumask *nmsk,
sibl = cpumask_next(sibl, siblmsk);
if (sibl >= nr_cpu_ids)
break;
- if (!cpumask_test_and_clear_cpu(sibl, nmsk))
- continue;
- cpumask_set_cpu(sibl, irqmsk);
+ __cpumask_clear_cpu(sibl, nmsk);
+ __cpumask_set_cpu(sibl, irqmsk);
cpus_per_grp--;
}
}
--
2.39.2