Re: [patch] export percpu cpuacct cgroup stats

[Ken Chen <kenchen@google.com>]

On Wed, Dec 3, 2008 at 9:34 PM, Li Zefan wrote:
>> +             seq_printf(m, "%lld ", percpu);
>
> Should be %llu. And if we don't cast percpu to unsigned long long, will
> it trigger compile warning in some archs?


On Thu, Dec 4, 2008 at 3:02 PM, Paul Menage wrote:
>> IMO percpu_usage is a better name.
>
> Maybe usage_percpu ?


Thank you all for your comments.  Patch updated.


=====

This patch export per-cpu CPU cycle usage for a given cpuacct cgroup.
There is a need for a user space monitor daemon to track group CPU
usage on per-cpu base.  It is also useful for monitor CFS load
balancer behavior by tracking per CPU group usage.


Signed-off-by: Ken Chen <kenchen@google.com>

diff --git a/kernel/sched.c b/kernel/sched.c
index b7480fb..e32c094 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -9345,12 +9345,34 @@ out:
 	return err;
 }

+static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft,
+				   struct seq_file *m)
+{
+	struct cpuacct *ca = cgroup_ca(cgroup);
+	u64 percpu;
+	int i;
+
+	for_each_possible_cpu(i) {
+		spin_lock_irq(&cpu_rq(i)->lock);
+		percpu = *percpu_ptr(ca->cpuusage, i);
+		spin_unlock_irq(&cpu_rq(i)->lock);
+		seq_printf(m, "%llu ", percpu);
+	}
+	seq_printf(m, "\n");
+	return 0;
+}
+
 static struct cftype files[] = {
 	{
 		.name = "usage",
 		.read_u64 = cpuusage_read,
 		.write_u64 = cpuusage_write,
 	},
+	{
+		.name = "usage_percpu",
+		.read_seq_string = cpuacct_percpu_seq_read,
+	},
+
 };

 static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)