linux-kernel - [RFC PATCH] sbitmap: remove unnecessary code in __sbitmap_queue_get

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Message-Id: <1661483653-27326-1-git-send-email-liusong@linux.alibaba.com>
Date:   Fri, 26 Aug 2022 11:14:13 +0800
From:   Liu Song <liusong@...ux.alibaba.com>
To:     axboe@...nel.dk
Cc:     linux-block@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [RFC PATCH] sbitmap: remove unnecessary code in __sbitmap_queue_get_batch

From: Liu Song <liusong@...ux.alibaba.com>

If "nr + nr_tags <= map_depth", then the value of nr_tags will not be
greater than map_depth, so no additional comparison is required.

Signed-off-by: Liu Song <liusong@...ux.alibaba.com>
---
 lib/sbitmap.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/lib/sbitmap.c b/lib/sbitmap.c
index 29eb048..34c904b 100644
--- a/lib/sbitmap.c
+++ b/lib/sbitmap.c
@@ -533,10 +533,9 @@ unsigned long __sbitmap_queue_get_batch(struct sbitmap_queue *sbq, int nr_tags,
 		nr = find_first_zero_bit(&map->word, map_depth);
 		if (nr + nr_tags <= map_depth) {
 			atomic_long_t *ptr = (atomic_long_t *) &map->word;
-			int map_tags = min_t(int, nr_tags, map_depth);
 			unsigned long val, ret;
 
-			get_mask = ((1UL << map_tags) - 1) << nr;
+			get_mask = ((1UL << nr_tags) - 1) << nr;
 			do {
 				val = READ_ONCE(map->word);
 				if ((val & ~get_mask) != val)
@@ -547,7 +546,7 @@ unsigned long __sbitmap_queue_get_batch(struct sbitmap_queue *sbq, int nr_tags,
 			if (get_mask) {
 				*offset = nr + (index << sb->shift);
 				update_alloc_hint_after_get(sb, depth, hint,
-							*offset + map_tags - 1);
+							*offset + nr_tags - 1);
 				return get_mask;
 			}
 		}
-- 
1.8.3.1