From: Paolo Valente <paolo.valente@linaro.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
ulf.hansson@linaro.org, linus.walleij@linaro.org,
broonie@kernel.org, bfq-iosched@googlegroups.com,
oleksandr@natalenko.name,
Paolo Valente <paolo.valente@linaro.org>
Subject: [PATCH BUGFIX/IMPROVEMENT 2/4] block, bfq: always update the budget of an entity when needed
Date: Thu, 16 Aug 2018 18:51:16 +0200 [thread overview]
Message-ID: <20180816165118.17402-3-paolo.valente@linaro.org> (raw)
In-Reply-To: <20180816165118.17402-1-paolo.valente@linaro.org>
When the next child entity to serve changes for a given parent entity,
the budget of that parent entity must be updated accordingly.
Unfortunately, this update is not performed, by mistake, for the
entities that happen to switch from having no child entity to serve,
to having one child entity to serve.
Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
---
block/bfq-wf2q.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/block/bfq-wf2q.c b/block/bfq-wf2q.c
index dbc07b456059..d558fd26740c 100644
--- a/block/bfq-wf2q.c
+++ b/block/bfq-wf2q.c
@@ -130,10 +130,14 @@ static bool bfq_update_next_in_service(struct bfq_sched_data *sd,
if (!change_without_lookup) /* lookup needed */
next_in_service = bfq_lookup_next_entity(sd, expiration);
- if (next_in_service)
- parent_sched_may_change = !sd->next_in_service ||
+ if (next_in_service) {
+ bool new_budget_triggers_change =
bfq_update_parent_budget(next_in_service);
+ parent_sched_may_change = !sd->next_in_service ||
+ new_budget_triggers_change;
+ }
+
sd->next_in_service = next_in_service;
if (!next_in_service)
--
2.16.1
next prev parent reply other threads:[~2018-08-16 16:52 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-16 16:51 [PATCH BUGFIX/IMPROVEMENT 0/4] bfq: two fixes and one improvement related to I/O control Paolo Valente
2018-08-16 16:51 ` [PATCH BUGFIX/IMPROVEMENT 1/4] block, bfq: readd missing reset of parent-entity service Paolo Valente
2018-08-16 16:51 ` Paolo Valente [this message]
2018-08-16 16:51 ` [PATCH BUGFIX/IMPROVEMENT 3/4] block, bfq: reduce write overcharge Paolo Valente
2018-08-16 16:51 ` [PATCH BUGFIX/IMPROVEMENT 4/4] block, bfq: improve code of bfq_bfqq_charge_time Paolo Valente
2018-08-16 19:10 ` [PATCH BUGFIX/IMPROVEMENT 0/4] bfq: two fixes and one improvement related to I/O control Jens Axboe
2018-08-17 16:21 ` Paolo Valente
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