[PATCH v3 1/9] cpumask: Make cpumask_full() check for nr_cpu_ids bits

From: Valentin Schneider
Date: Thu Aug 25 2022 - 14:13:01 EST


Consider a system with 4 CPUs and:
CONFIG_NR_CPUS=64
CONFIG_CPUMASK_OFFSTACK=n

In this situation, we have:
nr_cpumask_bits == NR_CPUS == 64
nr_cpu_ids = 4

Per smp.c::setup_nr_cpu_ids(), nr_cpu_ids <= NR_CPUS, so we want
cpumask_full() to check for nr_cpu_ids bits set.

This issue is currently pointed out by the cpumask KUnit tests:

[ 14.072028] # test_cpumask_weight: EXPECTATION FAILED at lib/test_cpumask.c:57
[ 14.072028] Expected cpumask_full(((const struct cpumask *)&__cpu_possible_mask)) to be true, but is false
[ 14.079333] not ok 1 - test_cpumask_weight

Signed-off-by: Valentin Schneider <vschneid@xxxxxxxxxx>
---
include/linux/cpumask.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index bd047864c7ac..1414ce8cd003 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -574,7 +574,7 @@ static inline bool cpumask_empty(const struct cpumask *srcp)
*/
static inline bool cpumask_full(const struct cpumask *srcp)
{
- return bitmap_full(cpumask_bits(srcp), nr_cpumask_bits);
+ return bitmap_full(cpumask_bits(srcp), nr_cpu_ids);
}

/**
--
2.31.1