Commit f1591a8b authored by Kemeng Shi's avatar Kemeng Shi Committed by Jens Axboe
Browse files

sbitmap: remove unnecessary calculation of alloc_hint in __sbitmap_get_shallow 



Updates to alloc_hint in the loop in __sbitmap_get_shallow() are mostly
pointless and equivalent to setting alloc_hint to zero (because
SB_NR_TO_BIT() considers only low sb->shift bits from alloc_hint). So
simplify the logic.

Reviewed-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarKemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230116205059.3821738-2-shikemeng@huaweicloud.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f1c006f1

lib/sbitmap.c

+4 −7
Original line number Diff line number Diff line
@@ -243,6 +243,7 @@ static int __sbitmap_get_shallow(struct sbitmap *sb, 
	int nr = -1;



	index = SB_NR_TO_INDEX(sb, alloc_hint);

	alloc_hint = SB_NR_TO_BIT(sb, alloc_hint);



	for (i = 0; i < sb->map_nr; i++) {

again:
@@ -250,7 +251,7 @@ static int __sbitmap_get_shallow(struct sbitmap *sb, 
					min_t(unsigned int,

					      __map_depth(sb, index),

					      shallow_depth),

					SB_NR_TO_BIT(sb, alloc_hint), true);

					alloc_hint, true);

		if (nr != -1) {

			nr += index << sb->shift;

			break;
@@ -260,13 +261,9 @@ static int __sbitmap_get_shallow(struct sbitmap *sb, 
			goto again;



		/* Jump to next index. */

		index++;

		alloc_hint = index << sb->shift;



		if (index >= sb->map_nr) {

			index = 0;

		alloc_hint = 0;

		}

		if (++index >= sb->map_nr)

			index = 0;

	}



	return nr;