linux-kernel - [PATCH 17/20] block, bfq: remove unnecessary traverse in bfq_add_to

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Message-ID: <20221101093417.10540-18-shikemeng@huawei.com>
Date:   Tue, 1 Nov 2022 17:34:14 +0800
From:   Kemeng Shi <shikemeng@...wei.com>
To:     <paolo.valente@...aro.org>, <axboe@...nel.dk>
CC:     <linux-block@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <shikemeng@...wei.com>
Subject: [PATCH 17/20] block, bfq: remove unnecessary traverse in bfq_add_to_burst

Do mark burst and remove from list in a single traverse to remove
unnecessary re-traverse.

Signed-off-by: Kemeng Shi <shikemeng@...wei.com>
---
 block/bfq-iosched.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 1402dfd9f448..0864254b8dcd 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -1255,7 +1255,7 @@ static void bfq_add_to_burst(struct bfq_data *bfqd, struct bfq_queue *bfqq)
 	bfqd->burst_size++;
 
 	if (bfqd->burst_size == bfqd->bfq_large_burst_thresh) {
-		struct bfq_queue *pos, *bfqq_item;
+		struct bfq_queue *pos;
 		struct hlist_node *n;
 
 		/*
@@ -1267,13 +1267,6 @@ static void bfq_add_to_burst(struct bfq_data *bfqd, struct bfq_queue *bfqq)
 		/*
 		 * We can now mark all queues in the burst list as
 		 * belonging to a large burst.
-		 */
-		hlist_for_each_entry(bfqq_item, &bfqd->burst_list,
-				     burst_list_node)
-			bfq_mark_bfqq_in_large_burst(bfqq_item);
-		bfq_mark_bfqq_in_large_burst(bfqq);
-
-		/*
 		 * From now on, and until the current burst finishes, any
 		 * new queue being activated shortly after the last queue
 		 * was inserted in the burst can be immediately marked as
@@ -1281,8 +1274,11 @@ static void bfq_add_to_burst(struct bfq_data *bfqd, struct bfq_queue *bfqq)
 		 * needed any more. Remove it.
 		 */
 		hlist_for_each_entry_safe(pos, n, &bfqd->burst_list,
-					  burst_list_node)
+					  burst_list_node) {
+			bfq_mark_bfqq_in_large_burst(pos);
 			hlist_del_init(&pos->burst_list_node);
+		}
+		bfq_mark_bfqq_in_large_burst(bfqq);
 	} else /*
 		* Burst not yet large: add bfqq to the burst list. Do
 		* not increment the ref counter for bfqq, because bfqq
-- 
2.30.0