| From | Thomas Gleixner <> | Subject | [patch 45/53] x86/cpu/topology: Simplify cpu_mark_primary_thread() | Date | Mon, 7 Aug 2023 15:53:44 +0200 (CEST) |
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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
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