This patch adds per cpuacct cgroup scheduler run-delay accounting. we
intent to use this stats to track group of tasks' wait time on CPU run
queue for monitoring purpose.
Due to lack of atomic64_t support on 32-bit arch, this functionality is
limited to 64-bit arch.
Signed-off-by: Ken Chen <[email protected]>
diff --git a/kernel/sched.c b/kernel/sched.c
index e4bb1dd..4d1920d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1390,6 +1390,15 @@ static void cpuacct_charge(
static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
#endif
+#if defined(CONFIG_CGROUP_CPUACCT) && defined(CONFIG_SCHEDSTATS) && \
+ defined(CONFIG_64BIT)
+static void
+cpuacct_accumulate_run_delay(struct task_struct *task, u64 delta);
+#else
+static inline void
+cpuacct_accumulate_run_delay(struct task_struct *t, u64 delta) {}
+#endif
+
static inline void inc_cpu_load(struct rq *rq, unsigned long load)
{
update_load_add(&rq->load, load);
@@ -9256,6 +9265,11 @@ struct cpuacct {
struct cgroup_subsys_state css;
/* cpuusage holds pointer to a u64-type object on every cpu */
u64 *cpuusage;
+
+#if defined(CONFIG_SCHEDSTATS) && defined(CONFIG_64BIT)
+ /* accumulative schedule rq wait time for tasks in this cgroup */
+ atomic64_t run_delay;
+#endif
};
struct cgroup_subsys cpuacct_subsys;
@@ -9347,12 +9361,33 @@ out:
return err;
}
+#if defined(CONFIG_SCHEDSTATS) && defined(CONFIG_64BIT)
+static u64 cpuacct_run_delay_read(struct cgroup *cgrp, struct cftype *cft)
+{
+ struct cpuacct *ca = cgroup_ca(cgrp);
+ return atomic64_read(&ca->run_delay);
+}
+
+static void cpuacct_accumulate_run_delay(struct task_struct *task, u64 delta)
+{
+ struct cpuacct *ca = task_ca(task);
+ if (ca)
+ atomic64_add(delta, &ca->run_delay);
+}
+#endif
+
static struct cftype files[] = {
{
.name = "usage",
.read_u64 = cpuusage_read,
.write_u64 = cpuusage_write,
},
+#if defined(CONFIG_SCHEDSTATS) && defined(CONFIG_64BIT)
+ {
+ .name = "run_delay",
+ .read_u64 = cpuacct_run_delay_read,
+ },
+#endif
};
static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
index 7dbf72a..4272594 100644
--- a/kernel/sched_stats.h
+++ b/kernel/sched_stats.h
@@ -180,6 +180,7 @@ static inline void sched_info_dequeued(
sched_info_reset_dequeued(t);
t->sched_info.run_delay += delta;
+ cpuacct_accumulate_run_delay(t, delta);
rq_sched_info_dequeued(task_rq(t), delta);
}
@@ -199,6 +200,7 @@ static void sched_info_arrive(
t->sched_info.last_arrival = now;
t->sched_info.pcount++;
+ cpuacct_accumulate_run_delay(t, delta);
rq_sched_info_arrive(task_rq(t), delta);
}
On Tue, 2008-12-16 at 23:51 -0800, Ken Chen wrote:
> This patch adds per cpuacct cgroup scheduler run-delay accounting. we
> intent to use this stats to track group of tasks' wait time on CPU run
> queue for monitoring purpose.
>
> Due to lack of atomic64_t support on 32-bit arch, this functionality is
> limited to 64-bit arch.
>
> Signed-off-by: Ken Chen <[email protected]>
You could add a seqcount instead?
> diff --git a/kernel/sched.c b/kernel/sched.c
> index e4bb1dd..4d1920d 100644
> --- a/kernel/sched.c
> +++ b/kernel/sched.c
> @@ -1390,6 +1390,15 @@ static void cpuacct_charge(
> static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {}
> #endif
>
> +#if defined(CONFIG_CGROUP_CPUACCT) && defined(CONFIG_SCHEDSTATS) && \
> + defined(CONFIG_64BIT)
> +static void
> +cpuacct_accumulate_run_delay(struct task_struct *task, u64 delta);
> +#else
> +static inline void
> +cpuacct_accumulate_run_delay(struct task_struct *t, u64 delta) {}
> +#endif
> +
> static inline void inc_cpu_load(struct rq *rq, unsigned long load)
> {
> update_load_add(&rq->load, load);
> @@ -9256,6 +9265,11 @@ struct cpuacct {
> struct cgroup_subsys_state css;
> /* cpuusage holds pointer to a u64-type object on every cpu */
> u64 *cpuusage;
> +
> +#if defined(CONFIG_SCHEDSTATS) && defined(CONFIG_64BIT)
> + /* accumulative schedule rq wait time for tasks in this cgroup */
> + atomic64_t run_delay;
> +#endif
> };
>
> struct cgroup_subsys cpuacct_subsys;
> @@ -9347,12 +9361,33 @@ out:
> return err;
> }
>
> +#if defined(CONFIG_SCHEDSTATS) && defined(CONFIG_64BIT)
> +static u64 cpuacct_run_delay_read(struct cgroup *cgrp, struct cftype *cft)
> +{
> + struct cpuacct *ca = cgroup_ca(cgrp);
> + return atomic64_read(&ca->run_delay);
> +}
> +
> +static void cpuacct_accumulate_run_delay(struct task_struct *task, u64 delta)
> +{
> + struct cpuacct *ca = task_ca(task);
> + if (ca)
> + atomic64_add(delta, &ca->run_delay);
> +}
> +#endif
> +
> static struct cftype files[] = {
> {
> .name = "usage",
> .read_u64 = cpuusage_read,
> .write_u64 = cpuusage_write,
> },
> +#if defined(CONFIG_SCHEDSTATS) && defined(CONFIG_64BIT)
> + {
> + .name = "run_delay",
> + .read_u64 = cpuacct_run_delay_read,
> + },
> +#endif
> };
>
> static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp)
> diff --git a/kernel/sched_stats.h b/kernel/sched_stats.h
> index 7dbf72a..4272594 100644
> --- a/kernel/sched_stats.h
> +++ b/kernel/sched_stats.h
> @@ -180,6 +180,7 @@ static inline void sched_info_dequeued(
> sched_info_reset_dequeued(t);
> t->sched_info.run_delay += delta;
>
> + cpuacct_accumulate_run_delay(t, delta);
> rq_sched_info_dequeued(task_rq(t), delta);
> }
>
> @@ -199,6 +200,7 @@ static void sched_info_arrive(
> t->sched_info.last_arrival = now;
> t->sched_info.pcount++;
>
> + cpuacct_accumulate_run_delay(t, delta);
> rq_sched_info_arrive(task_rq(t), delta);
> }