[PATCH 1/7] xfs: speed up xfs_iwalk_adjust_start a little bit

Darrick J. Wong
2023-12-31T20:04:43Z

Replace the open-coded loop that recomputes freecount with a single call
to a bit weight function.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/xfs_iwalk.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/fs/xfs/xfs_iwalk.c b/fs/xfs/xfs_iwalk.c
index b3275e8d47b60..4ce85423ef3e0 100644
--- a/fs/xfs/xfs_iwalk.c
+++ b/fs/xfs/xfs_iwalk.c
@@ -22,6 +22,7 @@
#include "xfs_trans.h"
#include "xfs_pwork.h"
#include "xfs_ag.h"
+#include "xfs_bit.h"

/*
* Walking Inodes in the Filesystem
@@ -131,21 +132,11 @@ xfs_iwalk_adjust_start(
struct xfs_inobt_rec_incore *irec) /* btree record */
{
int idx; /* index into inode chunk */
- int i;

idx = agino - irec->ir_startino;

- /*
- * We got a right chunk with some left inodes allocated at it. Grab
- * the chunk record. Mark all the uninteresting inodes free because
- * they're before our start point.
- */
- for (i = 0; i < idx; i++) {
- if (XFS_INOBT_MASK(i) & ~irec->ir_free)
- irec->ir_freecount++;
- }
-
irec->ir_free |= xfs_inobt_maskn(0, idx);
+ irec->ir_freecount = hweight64(irec->ir_free);
}

/* Allocate memory for a walk. */