The patch titled
Subject: ext4: use memweight()
has been removed from the -mm tree. Its filename was
ext4-use-memweight.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Subject: ext4: use memweight()
Convert ext4_count_free() to use memweight() instead of table lookup based
counting clear bits implementation. This change only affects the code
segments enabled by EXT4FS_DEBUG.
Note that this memweight() call can't be replaced with a single
bitmap_weight() call, although the pointer to the memory area is aligned
to long-word boundary. Because the size of the memory area may not be a
multiple of BITS_PER_LONG, then it returns wrong value on big-endian
architecture.
This also includes the following change.
- Remove unnecessary map == NULL check in ext4_count_free() which
always takes non-null pointer as the memory area.
Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ext4/bitmap.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)
diff -puN fs/ext4/bitmap.c~ext4-use-memweight fs/ext4/bitmap.c
--- a/fs/ext4/bitmap.c~ext4-use-memweight
+++ a/fs/ext4/bitmap.c
@@ -11,16 +11,9 @@
#include <linux/jbd2.h>
#include "ext4.h"
-static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
-
unsigned int ext4_count_free(char *bitmap, unsigned int numchars)
{
- unsigned int i, sum = 0;
-
- for (i = 0; i < numchars; i++)
- sum += nibblemap[bitmap[i] & 0xf] +
- nibblemap[(bitmap[i] >> 4) & 0xf];
- return sum;
+ return numchars * BITS_PER_BYTE - memweight(bitmap, numchars);
}
int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
_
Patches currently in -mm which might be from akinobu.mita@xxxxxxxxx are
origin.patch
fault-injection-fix-failcmdsh-warning.patch
linux-next.patch
ocfs2-use-find_last_bit.patch
ocfs2-use-bitmap_weight.patch
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