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sched: recover SD_WAKE_AFFINE in select_task_rq_fair and code clean up

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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>
This commit is contained in:
Alex Shi 2012-07-26 08:55:34 +08:00 committed by Thomas Gleixner
parent 78feefc512
commit f03542a701
4 changed files with 3 additions and 35 deletions
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1
include/linux/sched.h
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@ -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 */

2
include/linux/topology.h
View File

@ -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 \

1
kernel/sched/core.c
View File

@ -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

34
kernel/sched/fair.c
View File

@ -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)
@ -2703,27 +2702,6 @@ select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags)
if (!(tmp->flags & SD_LOAD_BALANCE))
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.
@ -2731,21 +2709,15 @@ select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags)
if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
affine_sd = tmp;
want_affine = 0;
break;
}
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);