diff options
| author |   David Sterba <dsterba@suse.com> | 2019-10-01 19:57:37 +0200 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2019-11-18 12:46:52 +0100 |
| commit | 4143cb8b6f00910e73a7503fd922211b9f08cf48 (patch) | |
| tree | 6e61a1f2ac756102f27cf4dc9a0ca19359259c81 /fs | |
| parent | btrfs: add __cold attribute to more functions (diff) | |
| download | linux-dev-4143cb8b6f00910e73a7503fd922211b9f08cf48.tar.xz linux-dev-4143cb8b6f00910e73a7503fd922211b9f08cf48.zip | |
btrfs: add const function attribute
For some reason the attribute is called __attribute_const__ and not
__const, marks functions that have no observable effects on program
state, IOW not reading pointers, just the arguments and calculating a
value. Allows the compiler to do some optimizations, based on
-Wsuggest-attribute=const . The effects are rather small, though, about
60 bytes decrese of btrfs.ko.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/ctree.h | 2 | ||||
| -rw-r--r-- | fs/btrfs/super.c | 2 | ||||
| -rw-r--r-- | fs/btrfs/volumes.c | 2 | ||||
| -rw-r--r-- | fs/btrfs/volumes.h | 2 |
4 files changed, 4 insertions, 4 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index b23fb083a1d5..8d7ac1cd49b4 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3141,7 +3141,7 @@ __cold void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function, unsigned int line, int errno, const char *fmt, ...); -const char *btrfs_decode_error(int errno); +const char * __attribute_const__ btrfs_decode_error(int errno); __cold void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 9c0c53e7d0fc..144933c9b507 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -66,7 +66,7 @@ static struct file_system_type btrfs_root_fs_type; static int btrfs_remount(struct super_block *sb, int *flags, char *data); -const char *btrfs_decode_error(int errno) +const char * __attribute_const__ btrfs_decode_error(int errno) { char *errstr = "unknown"; diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 173427731a69..d09371b0cdf9 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -297,7 +297,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, DEFINE_MUTEX(uuid_mutex); static LIST_HEAD(fs_uuids); -struct list_head *btrfs_get_fs_uuids(void) +struct list_head * __attribute_const__ btrfs_get_fs_uuids(void) { return &fs_uuids; } diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index a7da1f3e3627..0ae0677a8d86 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -571,7 +571,7 @@ static inline enum btrfs_raid_types btrfs_bg_flags_to_raid_index(u64 flags) void btrfs_commit_device_sizes(struct btrfs_transaction *trans); -struct list_head *btrfs_get_fs_uuids(void); +struct list_head * __attribute_const__ btrfs_get_fs_uuids(void); void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info); void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info); bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info, |