From: Thomas Gleixner Date: Tue, 13 Feb 2024 21:06:06 +0000 (+0100) Subject: x86/cpu/topology: Simplify cpu_mark_primary_thread() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=5e40fb2d4a4c7503cab4f923b7d985dbcf583581;p=linux.git x86/cpu/topology: Simplify cpu_mark_primary_thread() 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 Tested-by: Michael Kelley Tested-by: Sohil Mehta Link: https://lore.kernel.org/r/20240213210252.791176581@linutronix.de --- diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c index f3397e233ffbd..aea408de3be44 100644 --- a/arch/x86/kernel/cpu/topology.c +++ b/arch/x86/kernel/cpu/topology.c @@ -76,10 +76,7 @@ bool arch_match_cpu_phys_id(int cpu, u64 phys_id) #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