* [PATCH 2/2] Ext3: use unlikely to improve the efficiency of the kernel
@ 2013-01-12 9:36 shilong wang
2013-01-14 14:22 ` Jan Kara
0 siblings, 1 reply; 2+ messages in thread
From: shilong wang @ 2013-01-12 9:36 UTC (permalink / raw)
To: Jan Kara; +Cc: linux-fsdevel, linux-ext4
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.
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
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH 2/2] Ext3: use unlikely to improve the efficiency of the kernel
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
0 siblings, 0 replies; 2+ messages in thread
From: Jan Kara @ 2013-01-14 14:22 UTC (permalink / raw)
To: shilong wang; +Cc: Jan Kara, linux-fsdevel, linux-ext4
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
^ permalink raw reply [flat|nested] 2+ messages in thread
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