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/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);
