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[CPUFREQ] Fix memory leak in cpufreq_stat 

When a CPU is taken offline in an SMP system, cpufreq_remove_dev()
nulls out the per-cpu policy before cpufreq_stats_free_table() can
make use of it.  cpufreq_stats_free_table() then skips the
call to sysfs_remove_group(), leaving about 100 bytes of sysfs-related
memory unclaimed each time a CPU-removal occurs. Break up
cpu_stats_free_table into sysfs and table portions, and
call the sysfs portion early.

Signed-off-by: Steven Finney <steven.finney@palm.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Cc: stable@kernel.org
hifive-unleashed-5.1
steven finney 2011-05-02 11:29:17 -07:00 committed by Dave Jones
parent 335dc3335f
commit 98586ed8b8
1 changed files with 18 additions and 3 deletions
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21
drivers/cpufreq/cpufreq_stats.c
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@ -165,17 +165,27 @@ static int freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
return -1;
}
/* should be called late in the CPU removal sequence so that the stats
* memory is still available in case someone tries to use it.
*/
static void cpufreq_stats_free_table(unsigned int cpu)
{
struct cpufreq_stats *stat = per_cpu(cpufreq_stats_table, cpu);
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
if (policy && policy->cpu == cpu)
sysfs_remove_group(&policy->kobj, &stats_attr_group);
if (stat) {
kfree(stat->time_in_state);
kfree(stat);
}
per_cpu(cpufreq_stats_table, cpu) = NULL;
}
/* must be called early in the CPU removal sequence (before
* cpufreq_remove_dev) so that policy is still valid.
*/
static void cpufreq_stats_free_sysfs(unsigned int cpu)
{
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
if (policy && policy->cpu == cpu)
sysfs_remove_group(&policy->kobj, &stats_attr_group);
if (policy)
cpufreq_cpu_put(policy);
}
@ -316,6 +326,9 @@ static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
case CPU_ONLINE_FROZEN:
cpufreq_update_policy(cpu);
break;
case CPU_DOWN_PREPARE:
cpufreq_stats_free_sysfs(cpu);
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
cpufreq_stats_free_table(cpu);
@ -324,9 +337,11 @@ static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb,
return NOTIFY_OK;
}
/* priority=1 so this will get called before cpufreq_remove_dev */
static struct notifier_block cpufreq_stat_cpu_notifier __refdata =
{
.notifier_call = cpufreq_stat_cpu_callback,
.priority = 1,
};
static struct notifier_block notifier_policy_block = {