[PATCH] sched,fair: use list_for_each_entry() in print_cfs_stats()

From: Hui Su
Date: Fri Sep 25 2020 - 16:47:58 EST


Macro for_each_leaf_cfs_rq_safe() use list_for_each_entry_safe(),
which can against removal of list entry, but we only
print the cfs_rq data and won't remove the list entry in
print_cfs_stats().

Thus, add macro for_each_leaf_cfs_rq() based on
list_for_each_entry(), and use for_each_leaf_cfs_rq() in
print_cfs_stats().

Signed-off-by: Hui Su <sh_def@xxxxxxx>
---
kernel/sched/fair.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 1a68a0536add..d40dfb4349b0 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -391,11 +391,16 @@ static inline void assert_list_leaf_cfs_rq(struct rq *rq)
SCHED_WARN_ON(rq->tmp_alone_branch != &rq->leaf_cfs_rq_list);
}

-/* Iterate thr' all leaf cfs_rq's on a runqueue */
+/* Iterate thr' all leaf cfs_rq's on a runqueue safely */
#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 thr' all leaf cfs_rq's on a runqueue */
+#define for_each_leaf_cfs_rq(rq, cfs_rq) \
+ list_for_each_entry(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 *
is_same_group(struct sched_entity *se, struct sched_entity *pse)
@@ -11185,10 +11190,10 @@ 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();
}
--
2.25.1