[GIT PULL] scheduler fixes

Ingo Molnar
2012-04-27T06:39:19Z

Linus,

Please pull the latest sched-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched-urgent-for-linus

HEAD: fb2cf2c660971bea0ad86a9a5c19ad39eab61344 sched: Fix OOPS when build_sched_domains() percpu allocation fails

Thanks,

Ingo

------------------>
Peter Zijlstra (1):
sched: Fix more load-balancing fallout

he, bo (1):
sched: Fix OOPS when build_sched_domains() percpu allocation fails

kernel/sched/core.c | 22 ++++++++++++++++------
kernel/sched/fair.c | 18 ++++++++++--------
kernel/sched/features.h | 1 +
3 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4603b9d..0533a68 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -6405,16 +6405,26 @@ static void __sdt_free(const struct cpumask *cpu_map)
struct sd_data *sdd = &tl->data;

for_each_cpu(j, cpu_map) {
- struct sched_domain *sd = *per_cpu_ptr(sdd->sd, j);
- if (sd && (sd->flags & SD_OVERLAP))
- free_sched_groups(sd->groups, 0);
- kfree(*per_cpu_ptr(sdd->sd, j));
- kfree(*per_cpu_ptr(sdd->sg, j));
- kfree(*per_cpu_ptr(sdd->sgp, j));
+ struct sched_domain *sd;
+
+ if (sdd->sd) {
+ sd = *per_cpu_ptr(sdd->sd, j);
+ if (sd && (sd->flags & SD_OVERLAP))
+ free_sched_groups(sd->groups, 0);
+ kfree(*per_cpu_ptr(sdd->sd, j));
+ }
+
+ if (sdd->sg)
+ kfree(*per_cpu_ptr(sdd->sg, j));
+ if (sdd->sgp)
+ kfree(*per_cpu_ptr(sdd->sgp, j));
}
free_percpu(sdd->sd);
+ sdd->sd = NULL;
free_percpu(sdd->sg);
+ sdd->sg = NULL;
free_percpu(sdd->sgp);
+ sdd->sgp = NULL;
}
}

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 0d97ebd..e955364 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -784,7 +784,7 @@ account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
update_load_add(&rq_of(cfs_rq)->load, se->load.weight);
#ifdef CONFIG_SMP
if (entity_is_task(se))
- list_add_tail(&se->group_node, &rq_of(cfs_rq)->cfs_tasks);
+ list_add(&se->group_node, &rq_of(cfs_rq)->cfs_tasks);
#endif
cfs_rq->nr_running++;
}
@@ -3215,6 +3215,8 @@ static int move_one_task(struct lb_env *env)

static unsigned long task_h_load(struct task_struct *p);

+static const unsigned int sched_nr_migrate_break = 32;
+
/*
* move_tasks tries to move up to load_move weighted load from busiest to
* this_rq, as part of a balancing operation within domain "sd".
@@ -3242,7 +3244,7 @@ static int move_tasks(struct lb_env *env)

/* take a breather every nr_migrate tasks */
if (env->loop > env->loop_break) {
- env->loop_break += sysctl_sched_nr_migrate;
+ env->loop_break += sched_nr_migrate_break;
env->flags |= LBF_NEED_BREAK;
break;
}
@@ -3252,7 +3254,7 @@ static int move_tasks(struct lb_env *env)

load = task_h_load(p);

- if (load < 16 && !env->sd->nr_balance_failed)
+ if (sched_feat(LB_MIN) && load < 16 && !env->sd->nr_balance_failed)
goto next;

if ((load / 2) > env->load_move)
@@ -4407,7 +4409,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
.dst_cpu = this_cpu,
.dst_rq = this_rq,
.idle = idle,
- .loop_break = sysctl_sched_nr_migrate,
+ .loop_break = sched_nr_migrate_break,
};

cpumask_copy(cpus, cpu_active_mask);
@@ -4445,10 +4447,10 @@ redo:
* correctly treated as an imbalance.
*/
env.flags |= LBF_ALL_PINNED;
- env.load_move = imbalance;
- env.src_cpu = busiest->cpu;
- env.src_rq = busiest;
- env.loop_max = busiest->nr_running;
+ env.load_move = imbalance;
+ env.src_cpu = busiest->cpu;
+ env.src_rq = busiest;
+ env.loop_max = min_t(unsigned long, sysctl_sched_nr_migrate, busiest->nr_running);

more_balance:
local_irq_save(flags);
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index e61fd73..de00a48 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -68,3 +68,4 @@ SCHED_FEAT(TTWU_QUEUE, true)

SCHED_FEAT(FORCE_SD_OVERLAP, false)
SCHED_FEAT(RT_RUNTIME_SHARE, true)
+SCHED_FEAT(LB_MIN, false)