From: Jan Kara <jack@suse.cz>
To: shilong wang <wangshilong1991@gmail.com>
Cc: Jan Kara <jack@suse.cz>,
linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org
Subject: Re: [PATCH 2/2] Ext3: use unlikely to improve the efficiency of the kernel
Date: Mon, 14 Jan 2013 15:22:05 +0100 [thread overview]
Message-ID: <20130114142205.GE6597@quack.suse.cz> (raw)
In-Reply-To: <CAP9B-Q=GiV8fBk5cqR+yySUGidaFy=XKyNvZW=kQAKpqYsat4w@mail.gmail.com>
On Sat 12-01-13 01:36:17, shilong wang wrote:
> From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
>
> Because the function 'sb_getblk' seldomly fails to return
> NULL value,it will be better to use unlikely to check it.
Thanks. I've merged the patch. Here also applies my comment about line
wrapping from the previous patch...
Honza
>
> Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> ---
> fs/ext3/inode.c | 6 +++---
> fs/ext3/resize.c | 6 +++---
> fs/ext3/xattr.c | 2 +-
> 3 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
> index 61bc8bd..7338a76 100644
> --- a/fs/ext3/inode.c
> +++ b/fs/ext3/inode.c
> @@ -1083,7 +1083,7 @@ struct buffer_head *ext3_getblk(handle_t
> *handle, struct inode *inode,
> if (!err && buffer_mapped(&dummy)) {
> struct buffer_head *bh;
> bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
> - if (!bh) {
> + if (unlikely(!bh)) {
> *errp = -EIO;
> goto err;
> }
> @@ -2734,7 +2734,7 @@ static int __ext3_get_inode_loc(struct inode *inode,
> return -EIO;
>
> bh = sb_getblk(inode->i_sb, block);
> - if (!bh) {
> + if (unlikely(!bh)) {
> ext3_error (inode->i_sb, "ext3_get_inode_loc",
> "unable to read inode block - "
> "inode=%lu, block="E3FSBLK,
> @@ -2788,7 +2788,7 @@ static int __ext3_get_inode_loc(struct inode *inode,
>
> bitmap_bh = sb_getblk(inode->i_sb,
> le32_to_cpu(desc->bg_inode_bitmap));
> - if (!bitmap_bh)
> + if (unlikely(!bitmap_bh))
> goto make_io;
>
> /*
> diff --git a/fs/ext3/resize.c b/fs/ext3/resize.c
> index 0f814f3..704e8ce 100644
> --- a/fs/ext3/resize.c
> +++ b/fs/ext3/resize.c
> @@ -116,7 +116,7 @@ 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(-EIO);
> if ((err = ext3_journal_get_write_access(handle, bh))) {
> brelse(bh);
> @@ -234,7 +234,7 @@ static int setup_new_group_blocks(struct super_block *sb,
> goto exit_bh;
>
> gdb = sb_getblk(sb, block);
> - if (!gdb) {
> + if (unlikely(!gdb)) {
> err = -EIO;
> goto exit_bh;
> }
> @@ -722,7 +722,7 @@ static void update_backups(struct super_block *sb,
> break;
>
> bh = sb_getblk(sb, group * bpg + blk_off);
> - if (!bh) {
> + if (unlikely(!bh)) {
> err = -EIO;
> break;
> }
> diff --git a/fs/ext3/xattr.c b/fs/ext3/xattr.c
> index d22ebb7..9f57470 100644
> --- a/fs/ext3/xattr.c
> +++ b/fs/ext3/xattr.c
> @@ -813,7 +813,7 @@ inserted:
> ea_idebug(inode, "creating block %d", block);
>
> new_bh = sb_getblk(sb, block);
> - if (!new_bh) {
> + if (unlikely(!new_bh)) {
> getblk_failed:
> ext3_free_blocks(handle, inode, block, 1);
> error = -EIO;
> --
> 1.7.7.6
--
Jan Kara <jack@suse.cz>
SUSE Labs, CR
prev parent reply other threads:[~2013-01-14 14:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-12 9:36 [PATCH 2/2] Ext3: use unlikely to improve the efficiency of the kernel shilong wang
2013-01-14 14:22 ` Jan Kara [this message]
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