Added to the ext4 patch queue, thanks!!
- Ted
On Sun, Feb 06, 2011 at 12:53:53PM +0800, Coly Li wrote:
> In __mb_check_buddy(), look at the bellowed code,
>
> 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 <bosong.ly@xxxxxxxxxx>
> Cc: Alex Tomas <alex@xxxxxxxxxxxxx>
> Cc: Theodore Tso <tytso@xxxxxxxxxx>
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