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[5.3,114/166] block, bfq: push up injection only after setting service time

Message ID 20191006171222.946938472@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman Oct. 6, 2019, 5:21 p.m. UTC 
From: Paolo Valente <paolo.valente@linaro.org>


[ Upstream commit 58494c980f40274c465ebfdece02d401def088bf ]

If equal to 0, the injection limit for a bfq_queue is pushed to 1
after a first sample of the total service time of the I/O requests of
the queue is computed (to allow injection to start). Yet, because of a
mistake in the branch that performs this action, the push may happen
also in some other case. This commit fixes this issue.

Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>

Signed-off-by: Jens Axboe <axboe@kernel.dk>

Signed-off-by: Sasha Levin <sashal@kernel.org>

---
 block/bfq-iosched.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

-- 
2.20.1
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Patch

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index b33be928d164f..70bcbd02edcb1 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5809,12 +5809,14 @@  static void bfq_update_inject_limit(struct bfq_data *bfqd,
 	 */
 	if ((bfqq->last_serv_time_ns == 0 && bfqd->rq_in_driver == 1) ||
 	    tot_time_ns < bfqq->last_serv_time_ns) {
+		if (bfqq->last_serv_time_ns == 0) {
+			/*
+			 * Now we certainly have a base value: make sure we
+			 * start trying injection.
+			 */
+			bfqq->inject_limit = max_t(unsigned int, 1, old_limit);
+		}
 		bfqq->last_serv_time_ns = tot_time_ns;
-		/*
-		 * Now we certainly have a base value: make sure we
-		 * start trying injection.
-		 */
-		bfqq->inject_limit = max_t(unsigned int, 1, old_limit);
 	} else if (!bfqd->rqs_injected && bfqd->rq_in_driver == 1)
 		/*
 		 * No I/O injected and no request still in service in