ext4: reuse order and buddy in mb_mark_used when buddy split

After each buddy split, mb_mark_used will search the proper order
for the block which may consume some loop in mb_find_order_for_block.
In fact, we can reuse the order and buddy generated by the buddy split.

Reviewed by: lei.rao@intel.com
Signed-off-by: hanjinke <hanjinke.666@bytedance.com>
Link: https://lore.kernel.org/r/20220606155305.74146-1-hanjinke.666@bytedance.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
hanjinke 2022-06-06 23:53:05 +08:00 committed by Theodore Ts'o
parent 827891a38a
commit 218a69441b

View File

@ -1933,6 +1933,7 @@ static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
unsigned ret = 0;
int len0 = len;
void *buddy;
bool split = false;
BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
BUG_ON(e4b->bd_group != ex->fe_group);
@ -1957,12 +1958,16 @@ static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
/* let's maintain buddy itself */
while (len) {
ord = mb_find_order_for_block(e4b, start);
if (!split)
ord = mb_find_order_for_block(e4b, start);
if (((start >> ord) << ord) == start && len >= (1 << ord)) {
/* the whole chunk may be allocated at once! */
mlen = 1 << ord;
buddy = mb_find_buddy(e4b, ord, &max);
if (!split)
buddy = mb_find_buddy(e4b, ord, &max);
else
split = false;
BUG_ON((start >> ord) >= max);
mb_set_bit(start >> ord, buddy);
e4b->bd_info->bb_counters[ord]--;
@ -1989,6 +1994,7 @@ static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
mb_clear_bit(cur + 1, buddy);
e4b->bd_info->bb_counters[ord]++;
e4b->bd_info->bb_counters[ord]++;
split = true;
}
mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info);