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authorAlex Shi <alex.shi@intel.com>2012-07-26 08:55:34 +0800
committerThomas Gleixner <tglx@linutronix.de>2012-08-13 19:02:05 +0200
commitf03542a7019c600163ac4441d8a826c92c1bd510 (patch)
treecd644fb1d0feee636c400a58f4bddec30e2d95b9
parent78feefc512a09165627dd534111f651b6c8e605f (diff)
downloadlinaro-lsk-f03542a7019c600163ac4441d8a826c92c1bd510.tar.gz
sched: recover SD_WAKE_AFFINE in select_task_rq_fair and code clean up
Since power saving code was removed from sched now, the implement code is out of service in this function, and even pollute other logical. like, 'want_sd' never has chance to be set '0', that remove the effect of SD_WAKE_AFFINE here. So, clean up the obsolete code, includes SD_PREFER_LOCAL. Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/5028F431.6000306@intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--include/linux/sched.h1
-rw-r--r--include/linux/topology.h2
-rw-r--r--kernel/sched/core.c1
-rw-r--r--kernel/sched/fair.c34
4 files changed, 3 insertions, 35 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index b8c86648a2f..f3eebc121eb 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -860,7 +860,6 @@ enum cpu_idle_type {
#define SD_BALANCE_FORK 0x0008 /* Balance on fork, clone */
#define SD_BALANCE_WAKE 0x0010 /* Balance on wakeup */
#define SD_WAKE_AFFINE 0x0020 /* Wake task to waking CPU */
-#define SD_PREFER_LOCAL 0x0040 /* Prefer to keep tasks local to this domain */
#define SD_SHARE_CPUPOWER 0x0080 /* Domain members share cpu power */
#define SD_SHARE_PKG_RESOURCES 0x0200 /* Domain members share cpu pkg resources */
#define SD_SERIALIZE 0x0400 /* Only a single load balancing instance */
diff --git a/include/linux/topology.h b/include/linux/topology.h
index fec12d66721..d3cf0d6e771 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -129,7 +129,6 @@ int arch_update_cpu_topology(void);
| 1*SD_BALANCE_FORK \
| 0*SD_BALANCE_WAKE \
| 1*SD_WAKE_AFFINE \
- | 0*SD_PREFER_LOCAL \
| 0*SD_SHARE_CPUPOWER \
| 1*SD_SHARE_PKG_RESOURCES \
| 0*SD_SERIALIZE \
@@ -160,7 +159,6 @@ int arch_update_cpu_topology(void);
| 1*SD_BALANCE_FORK \
| 0*SD_BALANCE_WAKE \
| 1*SD_WAKE_AFFINE \
- | 0*SD_PREFER_LOCAL \
| 0*SD_SHARE_CPUPOWER \
| 0*SD_SHARE_PKG_RESOURCES \
| 0*SD_SERIALIZE \
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c9a3655e572..4376c9f3479 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6622,7 +6622,6 @@ sd_numa_init(struct sched_domain_topology_level *tl, int cpu)
| 0*SD_BALANCE_FORK
| 0*SD_BALANCE_WAKE
| 0*SD_WAKE_AFFINE
- | 0*SD_PREFER_LOCAL
| 0*SD_SHARE_CPUPOWER
| 0*SD_SHARE_PKG_RESOURCES
| 1*SD_SERIALIZE
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 287bfaca642..01d3eda6b7f 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2686,7 +2686,6 @@ select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags)
int prev_cpu = task_cpu(p);
int new_cpu = cpu;
int want_affine = 0;
- int want_sd = 1;
int sync = wake_flags & WF_SYNC;
if (p->nr_cpus_allowed == 1)
@@ -2704,48 +2703,21 @@ select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags)
continue;
/*
- * If power savings logic is enabled for a domain, see if we
- * are not overloaded, if so, don't balance wider.
- */
- if (tmp->flags & (SD_PREFER_LOCAL)) {
- unsigned long power = 0;
- unsigned long nr_running = 0;
- unsigned long capacity;
- int i;
-
- for_each_cpu(i, sched_domain_span(tmp)) {
- power += power_of(i);
- nr_running += cpu_rq(i)->cfs.nr_running;
- }
-
- capacity = DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE);
-
- if (nr_running < capacity)
- want_sd = 0;
- }
-
- /*
* If both cpu and prev_cpu are part of this domain,
* cpu is a valid SD_WAKE_AFFINE target.
*/
if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
affine_sd = tmp;
- want_affine = 0;
- }
-
- if (!want_sd && !want_affine)
break;
+ }
- if (!(tmp->flags & sd_flag))
- continue;
-
- if (want_sd)
+ if (tmp->flags & sd_flag)
sd = tmp;
}
if (affine_sd) {
- if (cpu == prev_cpu || wake_affine(affine_sd, p, sync))
+ if (cpu != prev_cpu && wake_affine(affine_sd, p, sync))
prev_cpu = cpu;
new_cpu = select_idle_sibling(p, prev_cpu);