From: Coly Li Date: Thu, 24 Feb 2011 18:24:18 +0000 (-0500) Subject: ext4: remove unncessary call mb_find_buddy() in debugging code X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=235772da3e2adb1f4d71f27ec5475093dd38b2ac;p=deliverable%2Flinux.git ext4: remove unncessary call mb_find_buddy() in debugging code In __mb_check_buddy(), look at the code below: 591 fstart = -1; 592 buddy = mb_find_buddy(e4b, 0, &max); 593 for (i = 0; i < max; i++) { 594 if (!mb_test_bit(i, buddy)) { 595 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free); 596 if (fstart == -1) { 597 fragments++; 598 fstart = i; 599 } 600 continue; 601 } 602 fstart = -1; 603 /* check used bits only */ 604 for (j = 0; j < e4b->bd_blkbits + 1; j++) { 605 buddy2 = mb_find_buddy(e4b, j, &max2); 606 k = i >> j; 607 MB_CHECK_ASSERT(k < max2); 608 MB_CHECK_ASSERT(mb_test_bit(k, buddy2)); 609 } 610 } 611 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info)); 612 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments); 613 614 grp = ext4_get_group_info(sb, e4b->bd_group); 615 buddy = mb_find_buddy(e4b, 0, &max); On line 592, buddy is fetched by mb_find_buddy() with order 0, between line 593 to line 615, buddy is not changed, therefore there is no need to fetch buddy again from mb_find_buddy() with order 0 again. We can safely remove the second mb_find_buddy() on line 615. Signed-off-by: Coly Li Cc: Alex Tomas Cc: Theodore Tso --- diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 1791dd4207d5..7de0e2824436 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -617,7 +617,6 @@ static int __mb_check_buddy(struct ext4_buddy *e4b, char *file, MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments); grp = ext4_get_group_info(sb, e4b->bd_group); - buddy = mb_find_buddy(e4b, 0, &max); list_for_each(cur, &grp->bb_prealloc_list) { ext4_group_t groupnr; struct ext4_prealloc_space *pa;