f2fs: add unlikely() macro for compiler optimization
As we know, some of our branch condition will rarely be true. So we could add
'unlikely' to let compiler optimize these code, by this way we could drop
unneeded 'jump' assemble code to improve performance.
change log:
o add *unlikely* as many as possible across the whole source files at once
suggested by Jaegeuk Kim.
Suggested-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index 38f4a224..6b21066 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -82,13 +82,12 @@
struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
/* Should not write any meta pages, if any IO error was occurred */
- if (wbc->for_reclaim || sbi->por_doing ||
- is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ERROR_FLAG)) {
- dec_page_count(sbi, F2FS_DIRTY_META);
- wbc->pages_skipped++;
- set_page_dirty(page);
- return AOP_WRITEPAGE_ACTIVATE;
- }
+ if (unlikely(sbi->por_doing ||
+ is_set_ckpt_flags(F2FS_CKPT(sbi), CP_ERROR_FLAG)))
+ goto redirty_out;
+
+ if (wbc->for_reclaim)
+ goto redirty_out;
wait_on_page_writeback(page);
@@ -96,6 +95,12 @@
dec_page_count(sbi, F2FS_DIRTY_META);
unlock_page(page);
return 0;
+
+redirty_out:
+ dec_page_count(sbi, F2FS_DIRTY_META);
+ wbc->pages_skipped++;
+ set_page_dirty(page);
+ return AOP_WRITEPAGE_ACTIVATE;
}
static int f2fs_write_meta_pages(struct address_space *mapping,
@@ -137,7 +142,7 @@
nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
PAGECACHE_TAG_DIRTY,
min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
- if (nr_pages == 0)
+ if (unlikely(nr_pages == 0))
break;
for (i = 0; i < nr_pages; i++) {
@@ -150,7 +155,8 @@
unlock_page(page);
break;
}
- if (nwritten++ >= nr_to_write)
+ nwritten++;
+ if (unlikely(nwritten >= nr_to_write))
break;
}
pagevec_release(&pvec);
@@ -200,7 +206,7 @@
max_orphans = (sbi->blocks_per_seg - 2 - NR_CURSEG_TYPE)
* F2FS_ORPHANS_PER_BLOCK;
mutex_lock(&sbi->orphan_inode_mutex);
- if (sbi->n_orphans >= max_orphans)
+ if (unlikely(sbi->n_orphans >= max_orphans))
err = -ENOSPC;
else
sbi->n_orphans++;
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 4e2fc09..2ce5a9e 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -251,7 +251,7 @@
if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC))
return -EPERM;
- if (!inc_valid_block_count(sbi, dn->inode, 1))
+ if (unlikely(!inc_valid_block_count(sbi, dn->inode, 1)))
return -ENOSPC;
trace_f2fs_reserve_new_block(dn->inode, dn->nid, dn->ofs_in_node);
@@ -711,7 +711,7 @@
zero_user_segment(page, offset, PAGE_CACHE_SIZE);
write:
- if (sbi->por_doing) {
+ if (unlikely(sbi->por_doing)) {
err = AOP_WRITEPAGE_ACTIVATE;
goto redirty_out;
}
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 594fc1b..0cc26ba 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -190,7 +190,7 @@
unsigned int max_depth;
unsigned int level;
- if (namelen > F2FS_NAME_LEN)
+ if (unlikely(namelen > F2FS_NAME_LEN))
return NULL;
if (npages == 0)
@@ -461,7 +461,7 @@
}
start:
- if (current_depth == MAX_DIR_HASH_DEPTH)
+ if (unlikely(current_depth == MAX_DIR_HASH_DEPTH))
return -ENOSPC;
/* Increase the depth, if required */
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 10eca02..dca18b3 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -574,7 +574,7 @@
static inline int check_nid_range(struct f2fs_sb_info *sbi, nid_t nid)
{
WARN_ON((nid >= NM_I(sbi)->max_nid));
- if (nid >= NM_I(sbi)->max_nid)
+ if (unlikely(nid >= NM_I(sbi)->max_nid))
return -EINVAL;
return 0;
}
@@ -600,7 +600,7 @@
spin_lock(&sbi->stat_lock);
valid_block_count =
sbi->total_valid_block_count + (block_t)count;
- if (valid_block_count > sbi->user_block_count) {
+ if (unlikely(valid_block_count > sbi->user_block_count)) {
spin_unlock(&sbi->stat_lock);
return false;
}
@@ -719,13 +719,13 @@
spin_lock(&sbi->stat_lock);
valid_block_count = sbi->total_valid_block_count + 1;
- if (valid_block_count > sbi->user_block_count) {
+ if (unlikely(valid_block_count > sbi->user_block_count)) {
spin_unlock(&sbi->stat_lock);
return false;
}
valid_node_count = sbi->total_valid_node_count + 1;
- if (valid_node_count > sbi->total_node_count) {
+ if (unlikely(valid_node_count > sbi->total_node_count)) {
spin_unlock(&sbi->stat_lock);
return false;
}
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 099f06f..2e41636 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -94,7 +94,7 @@
int i;
for (i = 0; i < FREE_NID_PAGES; i++, nid += NAT_ENTRY_PER_BLOCK) {
- if (nid >= nm_i->max_nid)
+ if (unlikely(nid >= nm_i->max_nid))
nid = 0;
index = current_nat_addr(sbi, nid);
@@ -1160,7 +1160,7 @@
struct page *page = pvec.pages[i];
/* until radix tree lookup accepts end_index */
- if (page->index > end)
+ if (unlikely(page->index > end))
continue;
if (ino && ino_of_node(page) == ino) {
@@ -1190,7 +1190,7 @@
block_t new_addr;
struct node_info ni;
- if (sbi->por_doing)
+ if (unlikely(sbi->por_doing))
goto redirty_out;
wait_on_page_writeback(page);
@@ -1326,7 +1326,7 @@
return -1;
/* 0 nid should not be used */
- if (nid == 0)
+ if (unlikely(nid == 0))
return 0;
if (build) {
@@ -1379,7 +1379,7 @@
for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
- if (start_nid >= nm_i->max_nid)
+ if (unlikely(start_nid >= nm_i->max_nid))
break;
blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
@@ -1413,7 +1413,7 @@
f2fs_put_page(page, 1);
nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK));
- if (nid >= nm_i->max_nid)
+ if (unlikely(nid >= nm_i->max_nid))
nid = 0;
if (i++ == FREE_NID_PAGES)
@@ -1447,7 +1447,7 @@
struct free_nid *i = NULL;
struct list_head *this;
retry:
- if (sbi->total_valid_node_count + 1 >= nm_i->max_nid)
+ if (unlikely(sbi->total_valid_node_count + 1 >= nm_i->max_nid))
return false;
spin_lock(&nm_i->free_nid_list_lock);
@@ -1557,7 +1557,7 @@
new_ni = old_ni;
new_ni.ino = ino;
- if (!inc_valid_node_count(sbi, NULL))
+ if (unlikely(!inc_valid_node_count(sbi, NULL)))
WARN_ON(1);
set_node_addr(sbi, &new_ni, NEW_ADDR);
inc_valid_inode_count(sbi);
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 26812fc..ea56376 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -457,7 +457,7 @@
int node_secs = get_blocktype_secs(sbi, F2FS_DIRTY_NODES);
int dent_secs = get_blocktype_secs(sbi, F2FS_DIRTY_DENTS);
- if (sbi->por_doing)
+ if (unlikely(sbi->por_doing))
return false;
return ((free_sections(sbi) + freed) <= (node_secs + 2 * dent_secs +