From aebf02430d25b6bd2b8542126fdcdb90e75a24b8 Mon Sep 17 00:00:00 2001 From: Wang Shilong Date: Sat, 12 Jan 2013 16:28:47 -0500 Subject: ext4: use unlikely to improve the efficiency of the kernel Because the function 'sb_getblk' seldomly fails to return NULL value,it will be better to use 'unlikely' to optimize it. Signed-off-by: Wang Shilong Signed-off-by: "Theodore Ts'o" --- fs/ext4/extents.c | 6 +++--- fs/ext4/inode.c | 6 +++--- fs/ext4/mmp.c | 2 +- fs/ext4/resize.c | 10 +++++----- fs/ext4/xattr.c | 2 +- 5 files changed, 13 insertions(+), 13 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index d42a8c49ad6..391e53a52e5 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -956,7 +956,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode, goto cleanup; } bh = sb_getblk(inode->i_sb, newblock); - if (!bh) { + if (unlikely(!bh)) { err = -ENOMEM; goto cleanup; } @@ -1029,7 +1029,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode, oldblock = newblock; newblock = ablocks[--a]; bh = sb_getblk(inode->i_sb, newblock); - if (!bh) { + if (unlikely(!bh)) { err = -ENOMEM; goto cleanup; } @@ -1142,7 +1142,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, return err; bh = sb_getblk(inode->i_sb, newblock); - if (!bh) + if (unlikely(!bh)) return -ENOMEM; lock_buffer(bh); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 9ccc140b82d..93a7e8453a6 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -713,7 +713,7 @@ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode, return NULL; bh = sb_getblk(inode->i_sb, map.m_pblk); - if (!bh) { + if (unlikely(!bh)) { *errp = -ENOMEM; return NULL; } @@ -3660,7 +3660,7 @@ static int __ext4_get_inode_loc(struct inode *inode, iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb); bh = sb_getblk(sb, block); - if (!bh) + if (unlikely(!bh)) return -ENOMEM; if (!buffer_uptodate(bh)) { lock_buffer(bh); @@ -3693,7 +3693,7 @@ static int __ext4_get_inode_loc(struct inode *inode, /* Is the inode bitmap in cache? */ bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp)); - if (!bitmap_bh) + if (unlikely(!bitmap_bh)) goto make_io; /* diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c index 44734f1ca55..f9b551561d2 100644 --- a/fs/ext4/mmp.c +++ b/fs/ext4/mmp.c @@ -93,7 +93,7 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh, *bh = NULL; } } - if (!*bh) { + if (unlikely(!*bh)) { ext4_warning(sb, "Error while reading MMP block %llu", mmp_block); return -EIO; diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 02824dc2ff3..05f8d4502d4 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -333,7 +333,7 @@ static struct buffer_head *bclean(handle_t *handle, struct super_block *sb, int err; bh = sb_getblk(sb, blk); - if (!bh) + if (unlikely(!bh)) return ERR_PTR(-ENOMEM); if ((err = ext4_journal_get_write_access(handle, bh))) { brelse(bh); @@ -410,7 +410,7 @@ static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle, return err; bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap); - if (!bh) + if (unlikely(!bh)) return -ENOMEM; err = ext4_journal_get_write_access(handle, bh); @@ -500,7 +500,7 @@ static int setup_new_flex_group_blocks(struct super_block *sb, goto out; gdb = sb_getblk(sb, block); - if (!gdb) { + if (unlikely(!gdb)) { err = -ENOMEM; goto out; } @@ -1064,7 +1064,7 @@ static void update_backups(struct super_block *sb, int blk_off, char *data, ext4_bg_has_super(sb, group)); bh = sb_getblk(sb, backup_block); - if (!bh) { + if (unlikely(!bh)) { err = -ENOMEM; break; } @@ -1168,7 +1168,7 @@ static int ext4_add_new_descs(handle_t *handle, struct super_block *sb, static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block) { struct buffer_head *bh = sb_getblk(sb, block); - if (!bh) + if (unlikely(!bh)) return NULL; if (!bh_uptodate_or_lock(bh)) { if (bh_submit_read(bh) < 0) { diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 07d684a4e52..c68990c392c 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -886,7 +886,7 @@ inserted: (unsigned long long)block); new_bh = sb_getblk(sb, block); - if (!new_bh) { + if (unlikely(!new_bh)) { error = -ENOMEM; getblk_failed: ext4_free_blocks(handle, inode, NULL, block, 1, -- cgit v1.2.3