[patch v5 04/15] sched: add sched balance policies in kernel

Alex Shi
2013-02-18T05:07:54Z

Current scheduler behavior is just consider for larger performance
of system. So it try to spread tasks on more cpu sockets and cpu cores

To adding the consideration of power awareness, the patchset adds
2 kinds of scheduler policy: powersaving and balance. They will use
runnable load util in scheduler balancing. The current scheduling is taken
as performance policy.

performance: the current scheduling behaviour, try to spread tasks
on more CPU sockets or cores. performance oriented.
powersaving: will pack tasks into few sched group until all LCPU in the
group is full, power oriented.
balance : will pack tasks into few sched group until group_capacity
numbers CPU is full, balance between performance and
powersaving.

The incoming patches will enable powersaving/balance scheduling in CFS.

Signed-off-by: Alex Shi <alex.shi@intel.com>
---
kernel/sched/fair.c | 3 +++
kernel/sched/sched.h | 6 ++++++
2 files changed, 9 insertions(+)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 350eb8d..2f98ffb 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6105,6 +6105,9 @@ static unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task
return rr_interval;
}

+/* The default scheduler policy is 'performance'. */
+int __read_mostly sched_balance_policy = SCHED_POLICY_PERFORMANCE;
+
/*
* All the scheduling class methods:
*/
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index ae3511e..7a19792 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -8,6 +8,12 @@

extern __read_mostly int scheduler_running;

+#define SCHED_POLICY_PERFORMANCE (0x1)
+#define SCHED_POLICY_POWERSAVING (0x2)
+#define SCHED_POLICY_BALANCE (0x4)
+
+extern int __read_mostly sched_balance_policy;
+
/*
* Convert user-nice values [ -20 ... 0 ... 19 ]
* to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
--
1.7.12