Commit 3e1e5f50 authored by Eric Sandeen's avatar Eric Sandeen Committed by Theodore Ts'o
Browse files

ext4: don't use ext4_allocation_contexts for tracing 



Many tracepoints were populating an ext4_allocation_context
to pass in, but this requires a slab allocation even when
tracepoints are off.  In fact, 4 of 5 of these allocations
were only for tracing.  In addition, we were only using a
small fraction of the 144 bytes of this structure for this
purpose.

We can do away with all these alloc/frees of the ac and
simply pass in the bits we care about, instead.

I tested this by turning on tracing and running through
xfstests on x86_64.  I did not actually do anything with
the trace output, however.

Signed-off-by: default avatarEric Sandeen <sandeen@redhat.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 4d547616

fs/ext4/mballoc.c

+12 −69
Original line number Diff line number Diff line
@@ -3591,8 +3591,7 @@ static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac) 
 */

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)

			struct ext4_prealloc_space *pa)

{

	struct super_block *sb = e4b->bd_sb;

	struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -3610,11 +3609,6 @@ ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh, 
	BUG_ON(group != e4b->bd_group && pa->pa_len != 0);

	end = bit + pa->pa_len;



	if (ac) {

		ac->ac_sb = sb;

		ac->ac_inode = pa->pa_inode;

	}



	while (bit < end) {

		bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);

		if (bit >= end)
@@ -3625,16 +3619,9 @@ ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh, 
			 (unsigned) next - bit, (unsigned) group);

		free += next - bit;



		if (ac) {

			ac->ac_b_ex.fe_group = group;

			ac->ac_b_ex.fe_start = bit;

			ac->ac_b_ex.fe_len = next - bit;

			ac->ac_b_ex.fe_logical = 0;

			trace_ext4_mballoc_discard(ac);

		}



		trace_ext4_mb_release_inode_pa(sb, ac, pa, grp_blk_start + bit,

					       next - bit);

		trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit);

		trace_ext4_mb_release_inode_pa(sb, pa->pa_inode, pa,

					       grp_blk_start + bit, next - bit);

		mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);

		bit = next + 1;

	}
@@ -3657,29 +3644,19 @@ ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh, 


static noinline_for_stack int

ext4_mb_release_group_pa(struct ext4_buddy *e4b,

				struct ext4_prealloc_space *pa,

				struct ext4_allocation_context *ac)

				struct ext4_prealloc_space *pa)

{

	struct super_block *sb = e4b->bd_sb;

	ext4_group_t group;

	ext4_grpblk_t bit;



	trace_ext4_mb_release_group_pa(sb, ac, pa);

	trace_ext4_mb_release_group_pa(sb, pa);

	BUG_ON(pa->pa_deleted == 0);

	ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);

	BUG_ON(group != e4b->bd_group && pa->pa_len != 0);

	mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);

	atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);



	if (ac) {

		ac->ac_sb = sb;

		ac->ac_inode = NULL;

		ac->ac_b_ex.fe_group = group;

		ac->ac_b_ex.fe_start = bit;

		ac->ac_b_ex.fe_len = pa->pa_len;

		ac->ac_b_ex.fe_logical = 0;

		trace_ext4_mballoc_discard(ac);

	}

	trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len);



	return 0;

}
@@ -3700,7 +3677,6 @@ ext4_mb_discard_group_preallocations(struct super_block *sb, 
	struct ext4_group_info *grp = ext4_get_group_info(sb, group);

	struct buffer_head *bitmap_bh = NULL;

	struct ext4_prealloc_space *pa, *tmp;

	struct ext4_allocation_context *ac;

	struct list_head list;

	struct ext4_buddy e4b;

	int err;
@@ -3729,9 +3705,6 @@ ext4_mb_discard_group_preallocations(struct super_block *sb, 
		needed = EXT4_BLOCKS_PER_GROUP(sb) + 1;



	INIT_LIST_HEAD(&list);

	ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);

	if (ac)

		ac->ac_sb = sb;

repeat:

	ext4_lock_group(sb, group);

	list_for_each_entry_safe(pa, tmp,
@@ -3786,9 +3759,9 @@ repeat: 
		spin_unlock(pa->pa_obj_lock);



		if (pa->pa_type == MB_GROUP_PA)

			ext4_mb_release_group_pa(&e4b, pa, ac);

			ext4_mb_release_group_pa(&e4b, pa);

		else

			ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa, ac);

			ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);



		list_del(&pa->u.pa_tmp_list);

		call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
@@ -3796,8 +3769,6 @@ repeat: 


out:

	ext4_unlock_group(sb, group);

	if (ac)

		kmem_cache_free(ext4_ac_cachep, ac);

	ext4_mb_unload_buddy(&e4b);

	put_bh(bitmap_bh);

	return free;
@@ -3818,7 +3789,6 @@ void ext4_discard_preallocations(struct inode *inode) 
	struct super_block *sb = inode->i_sb;

	struct buffer_head *bitmap_bh = NULL;

	struct ext4_prealloc_space *pa, *tmp;

	struct ext4_allocation_context *ac;

	ext4_group_t group = 0;

	struct list_head list;

	struct ext4_buddy e4b;
@@ -3834,11 +3804,6 @@ void ext4_discard_preallocations(struct inode *inode) 


	INIT_LIST_HEAD(&list);



	ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);

	if (ac) {

		ac->ac_sb = sb;

		ac->ac_inode = inode;

	}

repeat:

	/* first, collect all pa's in the inode */

	spin_lock(&ei->i_prealloc_lock);
@@ -3908,7 +3873,7 @@ repeat: 


		ext4_lock_group(sb, group);

		list_del(&pa->pa_group_list);

		ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa, ac);

		ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);

		ext4_unlock_group(sb, group);



		ext4_mb_unload_buddy(&e4b);
@@ -3917,8 +3882,6 @@ repeat: 
		list_del(&pa->u.pa_tmp_list);

		call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);

	}

	if (ac)

		kmem_cache_free(ext4_ac_cachep, ac);

}



/*
@@ -4116,14 +4079,10 @@ ext4_mb_discard_lg_preallocations(struct super_block *sb, 
	struct ext4_buddy e4b;

	struct list_head discard_list;

	struct ext4_prealloc_space *pa, *tmp;

	struct ext4_allocation_context *ac;



	mb_debug(1, "discard locality group preallocation\n");



	INIT_LIST_HEAD(&discard_list);

	ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);

	if (ac)

		ac->ac_sb = sb;



	spin_lock(&lg->lg_prealloc_lock);

	list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
@@ -4175,15 +4134,13 @@ ext4_mb_discard_lg_preallocations(struct super_block *sb, 
		}

		ext4_lock_group(sb, group);

		list_del(&pa->pa_group_list);

		ext4_mb_release_group_pa(&e4b, pa, ac);

		ext4_mb_release_group_pa(&e4b, pa);

		ext4_unlock_group(sb, group);



		ext4_mb_unload_buddy(&e4b);

		list_del(&pa->u.pa_tmp_list);

		call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);

	}

	if (ac)

		kmem_cache_free(ext4_ac_cachep, ac);

}



/*
@@ -4547,7 +4504,6 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode, 
{

	struct buffer_head *bitmap_bh = NULL;

	struct super_block *sb = inode->i_sb;

	struct ext4_allocation_context *ac = NULL;

	struct ext4_group_desc *gdp;

	unsigned long freed = 0;

	unsigned int overflow;
@@ -4602,12 +4558,6 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode, 
	if (!ext4_should_writeback_data(inode))

		flags |= EXT4_FREE_BLOCKS_METADATA;



	ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);

	if (ac) {

		ac->ac_inode = inode;

		ac->ac_sb = sb;

	}



do_more:

	overflow = 0;

	ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
@@ -4665,12 +4615,7 @@ do_more: 
			BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));

	}

#endif

	if (ac) {

		ac->ac_b_ex.fe_group = block_group;

		ac->ac_b_ex.fe_start = bit;

		ac->ac_b_ex.fe_len = count;

		trace_ext4_mballoc_free(ac);

	}

	trace_ext4_mballoc_free(sb, inode, block_group, bit, count);



	err = ext4_mb_load_buddy(sb, block_group, &e4b);

	if (err)
@@ -4741,7 +4686,5 @@ error_return: 
		dquot_free_block(inode, freed);

	brelse(bitmap_bh);

	ext4_std_error(sb, err);

	if (ac)

		kmem_cache_free(ext4_ac_cachep, ac);

	return;

}

include/trace/events/ext4.h

+29 −22
Original line number Diff line number Diff line
@@ -396,11 +396,11 @@ DEFINE_EVENT(ext4__mb_new_pa, ext4_mb_new_group_pa, 


TRACE_EVENT(ext4_mb_release_inode_pa,

	TP_PROTO(struct super_block *sb,

		 struct ext4_allocation_context *ac,

		 struct inode *inode,

		 struct ext4_prealloc_space *pa,

		 unsigned long long block, unsigned int count),



	TP_ARGS(sb, ac, pa, block, count),

	TP_ARGS(sb, inode, pa, block, count),



	TP_STRUCT__entry(

		__field(	dev_t,	dev			)
@@ -412,8 +412,7 @@ TRACE_EVENT(ext4_mb_release_inode_pa, 


	TP_fast_assign(

		__entry->dev		= sb->s_dev;

		__entry->ino		= (ac && ac->ac_inode) ? 

						ac->ac_inode->i_ino : 0;

		__entry->ino		= inode->i_ino;

		__entry->block		= block;

		__entry->count		= count;

	),
@@ -425,10 +424,9 @@ TRACE_EVENT(ext4_mb_release_inode_pa, 


TRACE_EVENT(ext4_mb_release_group_pa,

	TP_PROTO(struct super_block *sb,

		 struct ext4_allocation_context *ac,

		 struct ext4_prealloc_space *pa),



	TP_ARGS(sb, ac, pa),

	TP_ARGS(sb, pa),



	TP_STRUCT__entry(

		__field(	dev_t,	dev			)
@@ -779,47 +777,56 @@ TRACE_EVENT(ext4_mballoc_prealloc, 
);



DECLARE_EVENT_CLASS(ext4__mballoc,

	TP_PROTO(struct ext4_allocation_context *ac),

	TP_PROTO(struct super_block *sb,

		 struct inode *inode,

		 ext4_group_t group,

		 ext4_grpblk_t start,

		 ext4_grpblk_t len),



	TP_ARGS(ac),

	TP_ARGS(sb, inode, group, start, len),



	TP_STRUCT__entry(

		__field(	dev_t,	dev			)

		__field(	ino_t,	ino			)

		__field(	__u32, 	result_logical		)

		__field(	  int,	result_start		)

		__field(	__u32, 	result_group		)

		__field(	  int,	result_len		)

	),



	TP_fast_assign(

		__entry->dev		= ac->ac_sb->s_dev;

		__entry->ino		= ac->ac_inode ?

						ac->ac_inode->i_ino : 0;

		__entry->result_logical	= ac->ac_b_ex.fe_logical;

		__entry->result_start	= ac->ac_b_ex.fe_start;

		__entry->result_group	= ac->ac_b_ex.fe_group;

		__entry->result_len	= ac->ac_b_ex.fe_len;

		__entry->dev		= sb->s_dev;

		__entry->ino		= inode ? inode->i_ino : 0;

		__entry->result_start	= start;

		__entry->result_group	= group;

		__entry->result_len	= len;

	),



	TP_printk("dev %s inode %lu extent %u/%d/%u@%u ",

	TP_printk("dev %s inode %lu extent %u/%d/%u ",

		  jbd2_dev_to_name(__entry->dev), (unsigned long) __entry->ino,

		  __entry->result_group, __entry->result_start,

		  __entry->result_len, __entry->result_logical)

		  __entry->result_len)

);



DEFINE_EVENT(ext4__mballoc, ext4_mballoc_discard,



	TP_PROTO(struct ext4_allocation_context *ac),

	TP_PROTO(struct super_block *sb,

		 struct inode *inode,

		 ext4_group_t group,

		 ext4_grpblk_t start,

		 ext4_grpblk_t len),



	TP_ARGS(ac)

	TP_ARGS(sb, inode, group, start, len)

);



DEFINE_EVENT(ext4__mballoc, ext4_mballoc_free,



	TP_PROTO(struct ext4_allocation_context *ac),

	TP_PROTO(struct super_block *sb,

		 struct inode *inode,

		 ext4_group_t group,

		 ext4_grpblk_t start,

		 ext4_grpblk_t len),



	TP_ARGS(ac)

	TP_ARGS(sb, inode, group, start, len)

);



TRACE_EVENT(ext4_forget,

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