Commit e9d3c866 authored by Fam Zheng's avatar Fam Zheng Committed by Jens Axboe

bfq: Fix the missing barrier in __bfq_entity_update_weight_prio

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: default avatarFam Zheng <zhengfeiran@bytedance.com>
Reviewed-by: default avatarPaolo Valente <paolo.valente@linaro.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent a2614255
...@@ -744,6 +744,8 @@ __bfq_entity_update_weight_prio(struct bfq_service_tree *old_st, ...@@ -744,6 +744,8 @@ __bfq_entity_update_weight_prio(struct bfq_service_tree *old_st,
} }
#endif #endif
/* Matches the smp_wmb() in bfq_group_set_weight. */
smp_rmb();
old_st->wsum -= entity->weight; old_st->wsum -= entity->weight;
if (entity->new_weight != entity->orig_weight) { if (entity->new_weight != entity->orig_weight) {
......
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