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author | Akinobu Mita <akinobu.mita@gmail.com> | 2012-07-31 01:41:05 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-31 04:25:16 +0400 |
commit | ecd0afa3ced0ebf36901b53fd9ee431f8a34a161 (patch) | |
tree | f78190903beee21c2c2d872ed9645cbcb316796d /fs | |
parent | a75613ec73ec87726a81fe421385a13c25fdcfc4 (diff) | |
download | linux-ecd0afa3ced0ebf36901b53fd9ee431f8a34a161.tar.xz |
ext2: use memweight()
Convert ext2_count_free() to use memweight() instead of table lookup
based counting clear bits implementation. This change only affects the
code segments enabled by EXT2FS_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 changes.
- Remove unnecessary map == NULL check in ext2_count_free() which
always takes non-null pointer as the memory area.
- Fix printk format warning that only reveals with EXT2FS_DEBUG.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/ext2/balloc.c | 14 | ||||
-rw-r--r-- | fs/ext2/ialloc.c | 1 |
2 files changed, 3 insertions, 12 deletions
diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c index 1c3613998862..376aa77f3ca7 100644 --- a/fs/ext2/balloc.c +++ b/fs/ext2/balloc.c @@ -1444,19 +1444,9 @@ ext2_fsblk_t ext2_new_block(struct inode *inode, unsigned long goal, int *errp) #ifdef EXT2FS_DEBUG -static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0}; - -unsigned long ext2_count_free (struct buffer_head * map, unsigned int numchars) +unsigned long ext2_count_free(struct buffer_head *map, unsigned int numchars) { - unsigned int i; - unsigned long sum = 0; - - if (!map) - return (0); - for (i = 0; i < numchars; i++) - sum += nibblemap[map->b_data[i] & 0xf] + - nibblemap[(map->b_data[i] >> 4) & 0xf]; - return (sum); + return numchars * BITS_PER_BYTE - memweight(map->b_data, numchars); } #endif /* EXT2FS_DEBUG */ diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c index c13eb7b91a11..8f370e012e61 100644 --- a/fs/ext2/ialloc.c +++ b/fs/ext2/ialloc.c @@ -644,6 +644,7 @@ unsigned long ext2_count_free_inodes (struct super_block * sb) } brelse(bitmap_bh); printk("ext2_count_free_inodes: stored = %lu, computed = %lu, %lu\n", + (unsigned long) percpu_counter_read(&EXT2_SB(sb)->s_freeinodes_counter), desc_count, bitmap_count); return desc_count; |