cpumask: convert shared_cpu_map in acpi_processor* structs to cpumask_var_t

Impact: Reduce memory usage, use new API.

This is part of an effort to reduce structure sizes for machines
configured with large NR_CPUS.  cpumask_t gets replaced by
cpumask_var_t, which is either struct cpumask[1] (small NR_CPUS) or
struct cpumask * (large NR_CPUS).

(Changes to powernow-k* by <travis>.)

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 24 insertions, 3 deletions

diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index 88ea02dcb622..d0a001093b2d 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -517,6 +517,17 @@ acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
         }
 }
 
+static void free_acpi_perf_data(void)
+{
+        unsigned int i;
+
+        /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
+        for_each_possible_cpu(i)
+                free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
+                                 ->shared_cpu_map);
+        free_percpu(acpi_perf_data);
+}
+
 /*
  * acpi_cpufreq_early_init - initialize ACPI P-States library
  *
@@ -527,6 +538,7 @@ acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
  */
 static int __init acpi_cpufreq_early_init(void)
 {
+        unsigned int i;
         dprintk("acpi_cpufreq_early_init\n");
 
         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
@@ -534,6 +546,15 @@ static int __init acpi_cpufreq_early_init(void)
                 dprintk("Memory allocation error for acpi_perf_data.\n");
                 return -ENOMEM;
         }
+        for_each_possible_cpu(i) {
+                if (!alloc_cpumask_var(&per_cpu_ptr(acpi_perf_data, i)
+                                       ->shared_cpu_map, GFP_KERNEL)) {
+
+                        /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
+                        free_acpi_perf_data();
+                        return -ENOMEM;
+                }
+        }
 
         /* Do initialization in ACPI core */
         acpi_processor_preregister_performance(acpi_perf_data);
@@ -604,9 +625,9 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
          */
         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
-                policy->cpus = perf->shared_cpu_map;
+                cpumask_copy(&policy->cpus, perf->shared_cpu_map);
         }
-        policy->related_cpus = perf->shared_cpu_map;
+        cpumask_copy(&policy->related_cpus, perf->shared_cpu_map);
 
 #ifdef CONFIG_SMP
         dmi_check_system(sw_any_bug_dmi_table);
@@ -795,7 +816,7 @@ static int __init acpi_cpufreq_init(void)
 
         ret = cpufreq_register_driver(&acpi_cpufreq_driver);
         if (ret)
-                free_percpu(acpi_perf_data);
+                free_acpi_perf_data();
 
         return ret;
 }