Re: [RFC PATCH] ACPI / processor: Get accurate possible CPU count

[Dou Liyang]

Hi Andy,

At 03/15/2018 01:24 AM, Andy Shevchenko wrote:

On Wed, Mar 14, 2018 at 12:28 PM, Dou Liyang <douly.f...@cn.fujitsu.com> wrote:

+static void __init acpi_update_possible_map(void)
+{
+       unsigned int cpu, nr = 0;
+

+       if (nr_cpu_ids <= nr_unique_ids)
+               return;
+
+       for_each_possible_cpu(cpu) {
+               if (nr >= nr_unique_ids)
+                       set_cpu_possible(cpu, false);
+               nr++;
+       }

IIUC this can be optimized to:

Yes, I agree, It's smarter and clearer. Will use it.

Thanks,
        dou

if (nr_unique_ids >= nr_cpu_ids)
     return;

/* Don't yet figure out if it's superfluous */
if (nr_unique_ids >= cpumask_last(cpu_possible_mask))
     return;

for_each_cpu_wrap(cpu, cpu_possible_mask, nr_unique_ids)
     set_cpu_possible(cpu, false);

+       nr_cpu_ids = nr_unique_ids;
+       pr_info("Allowing %d possible CPUs\n", nr_cpu_ids);
+}