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Commit f93e65c1 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
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sched: Restore __cpu_power to a straight sum of power 



cpu_power is supposed to be a representation of the process
capacity of the cpu, not a value to randomly tweak in order to
affect placement.

Remove the placement hacks.

Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: default avatarAndreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: default avatarAndreas Herrmann <andreas.herrmann3@amd.com>
Acked-by: default avatarGautham R Shenoy <ego@in.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
LKML-Reference: <20090901083825.810860576@chello.nl>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 9aa55fbd

kernel/sched.c

+12 −16
Original line number Diff line number Diff line
@@ -8464,15 +8464,13 @@ static void free_sched_groups(const struct cpumask *cpu_map, 
 * there are asymmetries in the topology. If there are asymmetries, group

 * having more cpu_power will pickup more load compared to the group having

 * less cpu_power.

 *

 * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents

 * the maximum number of tasks a group can handle in the presence of other idle

 * or lightly loaded groups in the same sched domain.

 */

static void init_sched_groups_power(int cpu, struct sched_domain *sd)

{

	struct sched_domain *child;

	struct sched_group *group;

	long power;

	int weight;



	WARN_ON(!sd || !sd->groups);
@@ -8483,22 +8481,20 @@ static void init_sched_groups_power(int cpu, struct sched_domain *sd) 


	sd->groups->__cpu_power = 0;



	if (!child) {

		power = SCHED_LOAD_SCALE;

		weight = cpumask_weight(sched_domain_span(sd));

		/*

	 * For perf policy, if the groups in child domain share resources

	 * (for example cores sharing some portions of the cache hierarchy

	 * or SMT), then set this domain groups cpu_power such that each group

	 * can handle only one task, when there are other idle groups in the

	 * same sched domain.

		 * SMT siblings share the power of a single core.

		 */

	if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) &&

		       (child->flags &

			(SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) {

		sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE);

		if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1)

			power /= weight;

		sg_inc_cpu_power(sd->groups, power);

		return;

	}



	/*

	 * add cpu_power of each child group to this groups cpu_power

	 * Add cpu_power of each child group to this groups cpu_power.

	 */

	group = child->groups;

	do {