diff options
| author | steven finney <Steven.Finney@palm.com> | 2011-05-02 11:29:17 -0700 |
|---|---|---|
| committer | Dave Jones <davej@redhat.com> | 2011-05-04 11:50:57 -0400 |
| commit | 98586ed8b8878e10691203687e89a42fa3355300 (patch) | |
| tree | 728275611557268583bac0232c90b928151e3c66 /drivers/cpufreq/cpufreq_stats.c | |
| parent | 335dc3335ff692173bc766b248f7a97f3a23b30a (diff) | |
| download | lwn-98586ed8b8878e10691203687e89a42fa3355300.tar.gz lwn-98586ed8b8878e10691203687e89a42fa3355300.zip | |
[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
Diffstat (limited to 'drivers/cpufreq/cpufreq_stats.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq_stats.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c index 00d73fc8e4e2..4f1b8de2c9f3 100644 --- a/drivers/cpufreq/cpufreq_stats.c +++ b/drivers/cpufreq/cpufreq_stats.c @@ -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 = { |