Re: [PATCH v2] f2fs: add unlikely() macro for compiler more aggressively

Jaegeuk Kim
2013-12-10T08:04:23Z

>From d373d7084e4d132fa596fd5def1b9a9843e1410f Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Date: Fri, 6 Dec 2013 15:00:58 +0900
Subject: [PATCH] f2fs: add unlikely() macro for compiler more
aggressively

This patch adds unlikely() macro into the most of codes.
The basic rule is to add that when:
- checking unusual errors,
- checking page mappings,
- and the other unlikely conditions.

Change log from v1:
- Don't add unlikely for the NULL test and error test: advised by Andi
Kleen.

Cc: Chao Yu <chao2.yu@samsung.com>
Cc: Andi Kleen <andi@firstfloor.org>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
---
fs/f2fs/checkpoint.c | 10 +++++-----
fs/f2fs/data.c | 29 ++++++++++++++---------------
fs/f2fs/file.c | 9 ++++-----
fs/f2fs/gc.c | 3 +--
fs/f2fs/node.c | 28 ++++++++++++++--------------
fs/f2fs/recovery.c | 2 +-
fs/f2fs/super.c | 14 +++++++-------
fs/f2fs/xattr.c | 2 +-
8 files changed, 47 insertions(+), 50 deletions(-)

diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 6b21066..cf505eb 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -66,7 +66,7 @@ repeat:
goto repeat;

lock_page(page);
- if (page->mapping != mapping) {
+ if (unlikely(page->mapping != mapping)) {
f2fs_put_page(page, 1);
goto repeat;
}
@@ -473,7 +473,7 @@ static int __add_dirty_inode(struct inode *inode,
struct dir_inode_entry *new)
list_for_each(this, head) {
struct dir_inode_entry *entry;
entry = list_entry(this, struct dir_inode_entry, list);
- if (entry->inode == inode)
+ if (unlikely(entry->inode == inode))
return -EEXIST;
}
list_add_tail(&new->list, head);
@@ -783,7 +783,7 @@ static void do_checkpoint(struct f2fs_sb_info *sbi,
bool is_umount)
/* Here, we only have one bio having CP pack */
sync_meta_pages(sbi, META_FLUSH, LONG_MAX);

- if (!is_set_ckpt_flags(ckpt, CP_ERROR_FLAG)) {
+ if (unlikely(!is_set_ckpt_flags(ckpt, CP_ERROR_FLAG))) {
clear_prefree_segments(sbi);
F2FS_RESET_SB_DIRT(sbi);
}
@@ -840,11 +840,11 @@ int __init create_checkpoint_caches(void)
{
orphan_entry_slab = f2fs_kmem_cache_create("f2fs_orphan_entry",
sizeof(struct orphan_inode_entry), NULL);
- if (unlikely(!orphan_entry_slab))
+ if (!orphan_entry_slab)
return -ENOMEM;
inode_entry_slab = f2fs_kmem_cache_create("f2fs_dirty_dir_entry",
sizeof(struct dir_inode_entry), NULL);
- if (unlikely(!inode_entry_slab)) {
+ if (!inode_entry_slab) {
kmem_cache_destroy(orphan_entry_slab);
return -ENOMEM;
}
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 2ce5a9e..5607393 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -49,11 +49,11 @@ static void f2fs_read_end_io(struct bio *bio, int
err)
if (--bvec >= bio->bi_io_vec)
prefetchw(&bvec->bv_page->flags);

- if (uptodate) {
- SetPageUptodate(page);
- } else {
+ if (unlikely(!uptodate)) {
ClearPageUptodate(page);
SetPageError(page);
+ } else {
+ SetPageUptodate(page);
}
unlock_page(page);
} while (bvec >= bio->bi_io_vec);
@@ -73,7 +73,7 @@ static void f2fs_write_end_io(struct bio *bio, int
err)
if (--bvec >= bio->bi_io_vec)
prefetchw(&bvec->bv_page->flags);

- if (!uptodate) {
+ if (unlikely(!uptodate)) {
SetPageError(page);
set_bit(AS_EIO, &page->mapping->flags);
set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
@@ -249,7 +249,7 @@ int reserve_new_block(struct dnode_of_data *dn)
{
struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);

- if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC))
+ if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
return -EPERM;
if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
return -ENOSPC;
@@ -424,7 +424,7 @@ struct page *find_data_page(struct inode *inode,
pgoff_t index, bool sync)
return ERR_PTR(-ENOENT);

/* By fallocate(), there is no cached page, but with NEW_ADDR */
- if (dn.data_blkaddr == NEW_ADDR)
+ if (unlikely(dn.data_blkaddr == NEW_ADDR))
return ERR_PTR(-EINVAL);

page = grab_cache_page_write_begin(mapping, index, AOP_FLAG_NOFS);
@@ -443,7 +443,7 @@ struct page *find_data_page(struct inode *inode,
pgoff_t index, bool sync)

if (sync) {
wait_on_page_locked(page);
- if (!PageUptodate(page)) {
+ if (unlikely(!PageUptodate(page))) {
f2fs_put_page(page, 0);
return ERR_PTR(-EIO);
}
@@ -477,7 +477,7 @@ repeat:
}
f2fs_put_dnode(&dn);

- if (dn.data_blkaddr == NULL_ADDR) {
+ if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
f2fs_put_page(page, 1);
return ERR_PTR(-ENOENT);
}
@@ -502,11 +502,11 @@ repeat:
return ERR_PTR(err);

lock_page(page);
- if (!PageUptodate(page)) {
+ if (unlikely(!PageUptodate(page))) {
f2fs_put_page(page, 1);
return ERR_PTR(-EIO);
}
- if (page->mapping != mapping) {
+ if (unlikely(page->mapping != mapping)) {
f2fs_put_page(page, 1);
goto repeat;
}
@@ -534,7 +534,6 @@ struct page *get_new_data_page(struct inode *inode,
err = f2fs_reserve_block(&dn, index);
if (err)
return ERR_PTR(err);
-
repeat:
page = grab_cache_page(mapping, index);
if (!page)
@@ -552,11 +551,11 @@ repeat:
if (err)
return ERR_PTR(err);
lock_page(page);
- if (!PageUptodate(page)) {
+ if (unlikely(!PageUptodate(page))) {
f2fs_put_page(page, 1);
return ERR_PTR(-EIO);
}
- if (page->mapping != mapping) {
+ if (unlikely(page->mapping != mapping)) {
f2fs_put_page(page, 1);
goto repeat;
}
@@ -841,11 +840,11 @@ repeat:
if (err)
return err;
lock_page(page);
- if (!PageUptodate(page)) {
+ if (unlikely(!PageUptodate(page))) {
f2fs_put_page(page, 1);
return -EIO;
}
- if (page->mapping != mapping) {
+ if (unlikely(page->mapping != mapping)) {
f2fs_put_page(page, 1);
goto repeat;
}
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 2b47adc..5accc96 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -50,9 +50,9 @@ static int f2fs_vm_page_mkwrite(struct vm_area_struct
*vma,

file_update_time(vma->vm_file);
lock_page(page);
- if (page->mapping != inode->i_mapping ||
+ if (unlikely(page->mapping != inode->i_mapping ||
page_offset(page) > i_size_read(inode) ||
- !PageUptodate(page)) {
+ !PageUptodate(page))) {
unlock_page(page);
err = -EFAULT;
goto out;
@@ -120,7 +120,7 @@ int f2fs_sync_file(struct file *file, loff_t start,
loff_t end, int datasync)
.for_reclaim = 0,
};

- if (f2fs_readonly(inode->i_sb))
+ if (unlikely(f2fs_readonly(inode->i_sb)))
return 0;

trace_f2fs_sync_file_enter(inode);
@@ -241,7 +241,7 @@ static void truncate_partial_data_page(struct inode
*inode, u64 from)
return;

lock_page(page);
- if (page->mapping != inode->i_mapping) {
+ if (unlikely(page->mapping != inode->i_mapping)) {
f2fs_put_page(page, 1);
return;
}
@@ -516,7 +516,6 @@ static int expand_inode_data(struct inode *inode,
loff_t offset,
if (ret)
break;

-
if (pg_start == pg_end)
new_size = offset + len;
else if (index == pg_start && off_start)
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 2886aef..29ceb9d 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -119,7 +119,6 @@ int start_gc_thread(struct f2fs_sb_info *sbi)
kfree(gc_th);
sbi->gc_thread = NULL;
}
-
out:
return err;
}
@@ -695,7 +694,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi)

INIT_LIST_HEAD(&ilist);
gc_more:
- if (!(sbi->sb->s_flags & MS_ACTIVE))
+ if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE)))
goto stop;

if (gc_type == BG_GC && has_not_enough_free_secs(sbi, nfree)) {
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 2e41636..6c6ef77 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -750,7 +750,7 @@ skip_partial:
if (offset[1] == 0 &&
rn->i.i_nid[offset[0] - NODE_DIR1_BLOCK]) {
lock_page(page);
- if (page->mapping != node_mapping) {
+ if (unlikely(page->mapping != node_mapping)) {
f2fs_put_page(page, 1);
goto restart;
}
@@ -841,14 +841,14 @@ struct page *new_node_page(struct dnode_of_data
*dn,
struct page *page;
int err;

- if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC))
+ if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
return ERR_PTR(-EPERM);

page = grab_cache_page(mapping, dn->nid);
if (!page)
return ERR_PTR(-ENOMEM);

- if (!inc_valid_node_count(sbi, dn->inode)) {
+ if (unlikely(!inc_valid_node_count(sbi, dn->inode))) {
err = -ENOSPC;
goto fail;
}
@@ -898,7 +898,7 @@ static int read_node_page(struct page *page, int rw)

get_node_info(sbi, page->index, &ni);

- if (ni.blk_addr == NULL_ADDR) {
+ if (unlikely(ni.blk_addr == NULL_ADDR)) {
f2fs_put_page(page, 1);
return -ENOENT;
}
@@ -953,11 +953,11 @@ repeat:
goto got_it;

lock_page(page);
- if (!PageUptodate(page)) {
+ if (unlikely(!PageUptodate(page))) {
f2fs_put_page(page, 1);
return ERR_PTR(-EIO);
}
- if (page->mapping != mapping) {
+ if (unlikely(page->mapping != mapping)) {
f2fs_put_page(page, 1);
goto repeat;
}
@@ -1010,12 +1010,12 @@ repeat:
blk_finish_plug(&plug);

lock_page(page);
- if (page->mapping != mapping) {
+ if (unlikely(page->mapping != mapping)) {
f2fs_put_page(page, 1);
goto repeat;
}
page_hit:
- if (!PageUptodate(page)) {
+ if (unlikely(!PageUptodate(page))) {
f2fs_put_page(page, 1);
return ERR_PTR(-EIO);
}
@@ -1173,9 +1173,9 @@ int wait_on_node_pages_writeback(struct
f2fs_sb_info *sbi, nid_t ino)
cond_resched();
}

- if (test_and_clear_bit(AS_ENOSPC, &mapping->flags))
+ if (unlikely(test_and_clear_bit(AS_ENOSPC, &mapping->flags)))
ret2 = -ENOSPC;
- if (test_and_clear_bit(AS_EIO, &mapping->flags))
+ if (unlikely(test_and_clear_bit(AS_EIO, &mapping->flags)))
ret2 = -EIO;
if (!ret)
ret = ret2;
@@ -1202,7 +1202,7 @@ static int f2fs_write_node_page(struct page *page,
get_node_info(sbi, nid, &ni);

/* This page is already truncated */
- if (ni.blk_addr == NULL_ADDR) {
+ if (unlikely(ni.blk_addr == NULL_ADDR)) {
dec_page_count(sbi, F2FS_DIRTY_NODES);
unlock_page(page);
return 0;
@@ -1627,14 +1627,14 @@ int restore_node_summary(struct f2fs_sb_info
*sbi,
list_for_each_entry_safe(page, tmp, &page_list, lru) {

lock_page(page);
- if(PageUptodate(page)) {
+ if (unlikely(!PageUptodate(page))) {
+ err = -EIO;
+ } else {
rn = F2FS_NODE(page);
sum_entry->nid = rn->footer.nid;
sum_entry->version = 0;
sum_entry->ofs_in_node = 0;
sum_entry++;
- } else {
- err = -EIO;
}

list_del(&page->lru);
diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c
index d075465..a3f4542 100644
--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -430,7 +430,7 @@ int recover_fsync_data(struct f2fs_sb_info *sbi)

fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry",
sizeof(struct fsync_inode_entry), NULL);
- if (unlikely(!fsync_entry_slab))
+ if (!fsync_entry_slab)
return -ENOMEM;

INIT_LIST_HEAD(&inode_list);
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 22b07c3..68df44a 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -626,7 +626,7 @@ static struct inode *f2fs_nfs_get_inode(struct
super_block *sb,
struct f2fs_sb_info *sbi = F2FS_SB(sb);
struct inode *inode;

- if (ino < F2FS_ROOT_INO(sbi))
+ if (unlikely(ino < F2FS_ROOT_INO(sbi)))
return ERR_PTR(-ESTALE);

/*
@@ -637,7 +637,7 @@ static struct inode *f2fs_nfs_get_inode(struct
super_block *sb,
inode = f2fs_iget(sb, ino);
if (IS_ERR(inode))
return ERR_CAST(inode);
- if (generation && inode->i_generation != generation) {
+ if (unlikely(generation && inode->i_generation != generation)) {
/* we didn't find the right inode.. */
iput(inode);
return ERR_PTR(-ESTALE);
@@ -740,10 +740,10 @@ static int sanity_check_ckpt(struct f2fs_sb_info
*sbi)
fsmeta += le32_to_cpu(ckpt->rsvd_segment_count);
fsmeta += le32_to_cpu(raw_super->segment_count_ssa);

- if (fsmeta >= total)
+ if (unlikely(fsmeta >= total))
return 1;

- if (is_set_ckpt_flags(ckpt, CP_ERROR_FLAG)) {
+ if (unlikely(is_set_ckpt_flags(ckpt, CP_ERROR_FLAG))) {
f2fs_msg(sbi->sb, KERN_ERR, "A bug case: need to run fsck");
return 1;
}
@@ -808,7 +808,7 @@ retry:
brelse(*raw_super_buf);
f2fs_msg(sb, KERN_ERR, "Can't find a valid F2FS filesystem "
"in %dth superblock", block + 1);
- if(block == 0) {
+ if (block == 0) {
block++;
goto retry;
} else {
@@ -834,7 +834,7 @@ static int f2fs_fill_super(struct super_block *sb,
void *data, int silent)
return -ENOMEM;

/* set a block size */
- if (!sb_set_blocksize(sb, F2FS_BLKSIZE)) {
+ if (unlikely(!sb_set_blocksize(sb, F2FS_BLKSIZE))) {
f2fs_msg(sb, KERN_ERR, "unable to set blocksize");
goto free_sbi;
}
@@ -1066,7 +1066,7 @@ static int __init init_inodecache(void)
{
f2fs_inode_cachep = f2fs_kmem_cache_create("f2fs_inode_cache",
sizeof(struct f2fs_inode_info), NULL);
- if (f2fs_inode_cachep == NULL)
+ if (!f2fs_inode_cachep)
return -ENOMEM;
return 0;
}
diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
index aa7a3f1..b0fb8a2 100644
--- a/fs/f2fs/xattr.c
+++ b/fs/f2fs/xattr.c
@@ -522,7 +522,7 @@ static int __f2fs_setxattr(struct inode *inode, int
name_index,
if (found)
free = free + ENTRY_SIZE(here);

- if (free < newsize) {
+ if (unlikely(free < newsize)) {
error = -ENOSPC;
goto exit;
}
--
1.8.4.474.g128a96c

--
Jaegeuk Kim
Samsung