btrfs: add 'cold' compiler annotations to all error handling functions

The annotated functios will be placed into .text.unlikely section. The
annotation also hints compiler to move the code out of the hot paths,
and may implicitly mark if-statement leading to that block as unlikely.

This is a heuristic, the impact on the generated code is not
significant.

Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 98b33477235b33b9f26070e340b3d676501f18e3..670e4be7225bc51db35416b02285ee552c1acacb 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -4050,6 +4050,7 @@ void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
 
 #ifdef CONFIG_BTRFS_ASSERT
 
+__cold
 static inline void assfail(char *expr, char *file, int line)
 {
        pr_err("BTRFS: assertion failed: %s, file: %s, line: %d",
@@ -4065,10 +4066,12 @@ static inline void assfail(char *expr, char *file, int line)
 
 #define btrfs_assert()
 __printf(5, 6)
+__cold
 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
                     unsigned int line, int errno, const char *fmt, ...);
 
 
+__cold
 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root, const char *function,
                               unsigned int line, int errno);
@@ -4138,6 +4141,7 @@ do {                                                              \
 } while (0)
 
 __printf(5, 6)
+__cold
 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
                   unsigned int line, int errno, const char *fmt, ...);
 

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 3c72eea1271463772d5c2861f782d07d7da1c390..c761d8e068e8839297a6b0fed57e84cf88342ca8 100644 (file)
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -135,6 +135,7 @@ static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
  * __btrfs_std_error decodes expected errors from the caller and
  * invokes the approciate error response.
  */
+__cold
 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
                       unsigned int line, int errno, const char *fmt, ...)
 {
@@ -247,6 +248,7 @@ void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
  * We'll complete the cleanup in btrfs_end_transaction and
  * btrfs_commit_transaction.
  */
+__cold
 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
                               struct btrfs_root *root, const char *function,
                               unsigned int line, int errno)
@@ -273,6 +275,7 @@ void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
  * __btrfs_panic decodes unexpected, fatal errors from the caller,
  * issues an alert, and either panics or BUGs, depending on mount options.
  */
+__cold
 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
                   unsigned int line, int errno, const char *fmt, ...)
 {