@@ -3298,6 +3298,27 @@ void bfq_bfqq_expire(struct bfq_data *bfqd,
*/
} else
entity->service = 0;
+
+ /*
+ * Reset the received-service counter for every parent entity.
+ * Differently from what happens with bfqq->entity.service,
+ * the resetting of this counter never needs to be postponed
+ * for parent entities. In fact, in case bfqq may have a
+ * chance to go on being served using the last, partially
+ * consumed budget, bfqq->entity.service needs to be kept,
+ * because if bfqq then actually goes on being served using
+ * the same budget, the last value of bfqq->entity.service is
+ * needed to properly decrement bfqq->entity.budget by the
+ * portion already consumed. In contrast, it is not necessary
+ * to keep entity->service for parent entities too, because
+ * the bubble up of the new value of bfqq->entity.budget will
+ * make sure that the budgets of parent entities are correct,
+ * even in case bfqq and thus parent entities go on receiving
+ * service with the same budget.
+ */
+ entity = entity->parent;
+ for_each_entity(entity)
+ entity->service = 0;
}
/*
The received-service counter needs to be equal to 0 when an entity is set in service. Unfortunately, commit "block, bfq: fix service being wrongly set to zero in case of preemption" mistakenly removed the resetting of this counter for the parent entities of the bfq_queue being set in service. This commit fixes this issue by resetting service for parent entities, directly on the expiration of the in-service bfq_queue. Fixes: 9fae8dd59ff3 ("block, bfq: fix service being wrongly set to zero in case of preemption") Signed-off-by: Paolo Valente <paolo.valente@linaro.org> --- block/bfq-iosched.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) -- 2.16.1