Commit 4ddfef7b authored by Eric Sandeen's avatar Eric Sandeen Committed by Theodore Ts'o
Browse files

ext4: reduce mballoc stack usage with noinline_for_stack 



mballoc.c is a whole lot of static functions, which gcc seems to
really like to inline.

With the changes below, on x86, I can at least get from:

432 ext4_mb_new_blocks
240 ext4_mb_free_blocks
208 ext4_mb_discard_group_preallocations
188 ext4_mb_seq_groups_show
164 ext4_mb_init_cache
152 ext4_mb_release_inode_pa
136 ext4_mb_seq_history_show
...

to

220 ext4_mb_free_blocks
188 ext4_mb_seq_groups_show
176 ext4_mb_regular_allocator
164 ext4_mb_init_cache
156 ext4_mb_new_blocks
152 ext4_mb_release_inode_pa
136 ext4_mb_seq_history_show
124 ext4_mb_release_group_pa
...

which still has some big functions in there, but not 432 bytes!

Signed-off-by: default avatarEric Sandeen <sandeen@redhat.com>
Signed-off-by: default avatarMingming Cao <cmm@us.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 5cdd7b2d

fs/ext4/mballoc.c

+29 −16
Original line number Diff line number Diff line
@@ -1168,7 +1168,8 @@ out: 
	return err;

}



static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,

static noinline_for_stack int

ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,

					struct ext4_buddy *e4b)

{

	struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -1965,7 +1966,8 @@ static int ext4_mb_good_group(struct ext4_allocation_context *ac, 
	return 0;

}



static int ext4_mb_regular_allocator(struct ext4_allocation_context *ac)

static noinline_for_stack int

ext4_mb_regular_allocator(struct ext4_allocation_context *ac)

{

	ext4_group_t group;

	ext4_group_t i;
@@ -2465,7 +2467,8 @@ static void ext4_mb_history_init(struct super_block *sb) 
	/* if we can't allocate history, then we simple won't use it */

}



static void ext4_mb_store_history(struct ext4_allocation_context *ac)

static noinline_for_stack void

ext4_mb_store_history(struct ext4_allocation_context *ac)

{

	struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);

	struct ext4_mb_history h;
@@ -2801,7 +2804,8 @@ int ext4_mb_release(struct super_block *sb) 
	return 0;

}



static void ext4_mb_free_committed_blocks(struct super_block *sb)

static noinline_for_stack void

ext4_mb_free_committed_blocks(struct super_block *sb)

{

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	int err;
@@ -3021,7 +3025,8 @@ void exit_ext4_mballoc(void) 
 * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps

 * Returns 0 if success or error code

 */

static int ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,

static noinline_for_stack int

ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,

				handle_t *handle)

{

	struct buffer_head *bitmap_bh = NULL;
@@ -3138,7 +3143,8 @@ static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac) 
 * Normalization means making request better in terms of

 * size and alignment

 */

static void ext4_mb_normalize_request(struct ext4_allocation_context *ac,

static noinline_for_stack void

ext4_mb_normalize_request(struct ext4_allocation_context *ac,

				struct ext4_allocation_request *ar)

{

	int bsbits, max;
@@ -3404,7 +3410,8 @@ static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac, 
/*

 * search goal blocks in preallocated space

 */

static int ext4_mb_use_preallocated(struct ext4_allocation_context *ac)

static noinline_for_stack int

ext4_mb_use_preallocated(struct ext4_allocation_context *ac)

{

	struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);

	struct ext4_locality_group *lg;
@@ -3571,7 +3578,8 @@ static void ext4_mb_put_pa(struct ext4_allocation_context *ac, 
/*

 * creates new preallocated space for given inode

 */

static int ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)

static noinline_for_stack int

ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)

{

	struct super_block *sb = ac->ac_sb;

	struct ext4_prealloc_space *pa;
@@ -3658,7 +3666,8 @@ static int ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) 
/*

 * creates new preallocated space for locality group inodes belongs to

 */

static int ext4_mb_new_group_pa(struct ext4_allocation_context *ac)

static noinline_for_stack int

ext4_mb_new_group_pa(struct ext4_allocation_context *ac)

{

	struct super_block *sb = ac->ac_sb;

	struct ext4_locality_group *lg;
@@ -3731,8 +3740,8 @@ static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac) 
 * the caller MUST hold group/inode locks.

 * TODO: optimize the case when there are no in-core structures yet

 */

static int ext4_mb_release_inode_pa(struct ext4_buddy *e4b,

				struct buffer_head *bitmap_bh,

static noinline_for_stack int

ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,

				struct ext4_prealloc_space *pa)

{

	struct ext4_allocation_context *ac;
@@ -3803,7 +3812,8 @@ static int ext4_mb_release_inode_pa(struct ext4_buddy *e4b, 
	return err;

}



static int ext4_mb_release_group_pa(struct ext4_buddy *e4b,

static noinline_for_stack int

ext4_mb_release_group_pa(struct ext4_buddy *e4b,

				struct ext4_prealloc_space *pa)

{

	struct ext4_allocation_context *ac;
@@ -3845,7 +3855,8 @@ static int ext4_mb_release_group_pa(struct ext4_buddy *e4b, 
 * - how many do we discard

 *   1) how many requested

 */

static int ext4_mb_discard_group_preallocations(struct super_block *sb,

static noinline_for_stack int

ext4_mb_discard_group_preallocations(struct super_block *sb,

					ext4_group_t group, int needed)

{

	struct ext4_group_info *grp = ext4_get_group_info(sb, group);
@@ -4167,7 +4178,8 @@ static void ext4_mb_group_or_file(struct ext4_allocation_context *ac) 
	mutex_lock(&ac->ac_lg->lg_mutex);

}



static int ext4_mb_initialize_context(struct ext4_allocation_context *ac,

static noinline_for_stack int

ext4_mb_initialize_context(struct ext4_allocation_context *ac,

				struct ext4_allocation_request *ar)

{

	struct super_block *sb = ar->inode->i_sb;
@@ -4398,7 +4410,8 @@ static void ext4_mb_poll_new_transaction(struct super_block *sb, 
	ext4_mb_free_committed_blocks(sb);

}



static int ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,

static noinline_for_stack int

ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,

			  ext4_group_t group, ext4_grpblk_t block, int count)

{

	struct ext4_group_info *db = e4b->bd_info;

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