sched: allow cpuacct stats to be reset
Currently the schedstats implementation does not allow the statistics
to be reset. This patch aims to allow that.
echo 0 > cpuacct.usage
resets the usage. Any other value is not allowed and returns -EINVAL.
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched.c b/kernel/sched.c
index e2f85c7..e4bf447 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -8381,10 +8381,34 @@
return totalcpuusage;
}
+static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype,
+ u64 reset)
+{
+ struct cpuacct *ca = cgroup_ca(cgrp);
+ int err = 0;
+ int i;
+
+ if (reset) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ for_each_possible_cpu(i) {
+ u64 *cpuusage = percpu_ptr(ca->cpuusage, i);
+
+ spin_lock_irq(&cpu_rq(i)->lock);
+ *cpuusage = 0;
+ spin_unlock_irq(&cpu_rq(i)->lock);
+ }
+out:
+ return err;
+}
+
static struct cftype files[] = {
{
.name = "usage",
.read_uint = cpuusage_read,
+ .write_uint = cpuusage_write,
},
};