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>

diff --git a/include/linux/sched.h b/include/linux/sched.h
index b8c86648a2f95dc6f83aab668fd9a7e07f277b4e..f3eebc121ebc1cbc8c6b4eb175186bf7033e2126 100644 (file)
--- 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 fec12d667211dd398ba07ed5127b9e3485bcdd49..d3cf0d6e7712c115fb529559b59c2ae4f6f8cd9c 100644 (file)
--- 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 c9a3655e572dacbb3e2c7bacbb52353d4cc58c8d..4376c9f34790e32af5676942f1dc204c89991810 100644 (file)
--- 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 287bfaca64205135a5746408cfc83d0dea3c6684..01d3eda6b7f926bd353a8d991e4199a461f117a1 100644 (file)
--- 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)
@@ -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;
-               }
-
-               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);