The comment of bfq_group_set_weight says the reading of prio_changed
should happen before the reading of weight, but a memory barrier is
missing here. Add it now, to match the smp_wmb() there.
Signed-off-by: Fam Zheng <zhengfeiran@xxxxxxxxxxxxx>
---
block/bfq-wf2q.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c
index c9ba225081ce..05f0bf4a1144 100644
--- a/block/bfq-wf2q.c
+++ b/block/bfq-wf2q.c
@@ -744,6 +744,8 @@ __bfq_entity_update_weight_prio(struct bfq_service_tree *old_st,
}
#endif
+ /* Matches the smp_wmb() in bfq_group_set_weight. */
+ smp_rmb();
old_st->wsum -= entity->weight;
if (entity->new_weight != entity->orig_weight) {
--
2.11.0
