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authorLinus Torvalds <torvalds@linux-foundation.org>2018-12-31 09:54:17 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-12-31 09:54:17 -0800
commite3ed513bcf0097c0b8a1f1b4d791a8d0d8933b3b (patch)
treee2b21b72c2cbd3e2914cffe8c2fc9739ba122afd /kernel
parent2a1a2c1a76cf89aaeb98a89179c2942c7882f68a (diff)
parentc40f7d74c741a907cfaeb73a7697081881c497d0 (diff)
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Ingo Molnar: "This is a revert for a lockup in cgroups-intense workloads - the real fixes will come later" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Fix infinite loop in update_blocked_averages() by reverting a9e7f6544b9c
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched/fair.c43
1 files changed, 9 insertions, 34 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index d1907506318a..6483834f1278 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -352,10 +352,9 @@ static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
}
}
-/* Iterate thr' all leaf cfs_rq's on a runqueue */
-#define for_each_leaf_cfs_rq_safe(rq, cfs_rq, pos) \
- list_for_each_entry_safe(cfs_rq, pos, &rq->leaf_cfs_rq_list, \
- leaf_cfs_rq_list)
+/* Iterate through all leaf cfs_rq's on a runqueue: */
+#define for_each_leaf_cfs_rq(rq, cfs_rq) \
+ list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list)
/* Do the two (enqueued) entities belong to the same group ? */
static inline struct cfs_rq *
@@ -447,8 +446,8 @@ static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
{
}
-#define for_each_leaf_cfs_rq_safe(rq, cfs_rq, pos) \
- for (cfs_rq = &rq->cfs, pos = NULL; cfs_rq; cfs_rq = pos)
+#define for_each_leaf_cfs_rq(rq, cfs_rq) \
+ for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL)
static inline struct sched_entity *parent_entity(struct sched_entity *se)
{
@@ -7647,27 +7646,10 @@ static inline bool others_have_blocked(struct rq *rq)
#ifdef CONFIG_FAIR_GROUP_SCHED
-static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq)
-{
- if (cfs_rq->load.weight)
- return false;
-
- if (cfs_rq->avg.load_sum)
- return false;
-
- if (cfs_rq->avg.util_sum)
- return false;
-
- if (cfs_rq->avg.runnable_load_sum)
- return false;
-
- return true;
-}
-
static void update_blocked_averages(int cpu)
{
struct rq *rq = cpu_rq(cpu);
- struct cfs_rq *cfs_rq, *pos;
+ struct cfs_rq *cfs_rq;
const struct sched_class *curr_class;
struct rq_flags rf;
bool done = true;
@@ -7679,7 +7661,7 @@ static void update_blocked_averages(int cpu)
* Iterates the task_group tree in a bottom up fashion, see
* list_add_leaf_cfs_rq() for details.
*/
- for_each_leaf_cfs_rq_safe(rq, cfs_rq, pos) {
+ for_each_leaf_cfs_rq(rq, cfs_rq) {
struct sched_entity *se;
/* throttled entities do not contribute to load */
@@ -7694,13 +7676,6 @@ static void update_blocked_averages(int cpu)
if (se && !skip_blocked_update(se))
update_load_avg(cfs_rq_of(se), se, 0);
- /*
- * There can be a lot of idle CPU cgroups. Don't let fully
- * decayed cfs_rqs linger on the list.
- */
- if (cfs_rq_is_decayed(cfs_rq))
- list_del_leaf_cfs_rq(cfs_rq);
-
/* Don't need periodic decay once load/util_avg are null */
if (cfs_rq_has_blocked(cfs_rq))
done = false;
@@ -10570,10 +10545,10 @@ const struct sched_class fair_sched_class = {
#ifdef CONFIG_SCHED_DEBUG
void print_cfs_stats(struct seq_file *m, int cpu)
{
- struct cfs_rq *cfs_rq, *pos;
+ struct cfs_rq *cfs_rq;
rcu_read_lock();
- for_each_leaf_cfs_rq_safe(cpu_rq(cpu), cfs_rq, pos)
+ for_each_leaf_cfs_rq(cpu_rq(cpu), cfs_rq)
print_cfs_rq(m, cpu, cfs_rq);
rcu_read_unlock();
}