[patch 45/53] x86/cpu/topology: Simplify cpu_mark_primary_thread()

Thomas Gleixner
2023-08-07T13:56:18Z

No point in creating a mask via fls(). smp_num_siblings is guaranteed to be
a power of 2. So just using (smp_num_siblings - 1) has the same effect.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/kernel/cpu/topology.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

--- a/arch/x86/kernel/cpu/topology.c
+++ b/arch/x86/kernel/cpu/topology.c
@@ -86,10 +86,7 @@ bool arch_match_cpu_phys_id(int cpu, u64
#ifdef CONFIG_SMP
static void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid)
{
- /* Isolate the SMT bit(s) in the APICID and check for 0 */
- u32 mask = (1U << (fls(smp_num_siblings) - 1)) - 1;
-
- if (smp_num_siblings == 1 || !(apicid & mask))
+ if (!(apicid & (smp_num_siblings - 1)))
cpumask_set_cpu(cpu, &__cpu_primary_thread_mask);
}
#else