Commit 3dea728c authored by Kent Overstreet's avatar Kent Overstreet Committed by Kent Overstreet
Browse files

bcachefs: New tracepoint for bch2_trans_get_iter() 



Trying to debug an issue where after traverse_all() we shouldn't have to
traverse any iterators... yet we are

Signed-off-by: default avatarKent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: default avatarKent Overstreet <kent.overstreet@linux.dev>
parent d36cdb04

fs/bcachefs/btree_iter.c

+23 −9
Original line number Diff line number Diff line
@@ -2020,6 +2020,13 @@ struct btree_iter *__bch2_trans_get_iter(struct btree_trans *trans, 
					 unsigned flags)

{

	struct btree_iter *iter, *best = NULL;

	struct bpos real_pos, pos_min = POS_MIN;



	if ((flags & BTREE_ITER_TYPE) != BTREE_ITER_NODES &&

	    btree_node_type_is_extents(btree_id) &&

	    !(flags & BTREE_ITER_NOT_EXTENTS) &&

	    !(flags & BTREE_ITER_ALL_SNAPSHOTS))

		flags |= BTREE_ITER_IS_EXTENTS;



	if ((flags & BTREE_ITER_TYPE) != BTREE_ITER_NODES &&

	    !btree_type_has_snapshots(btree_id))
@@ -2029,6 +2036,12 @@ struct btree_iter *__bch2_trans_get_iter(struct btree_trans *trans, 
		pos.snapshot = btree_type_has_snapshots(btree_id)

			? U32_MAX : 0;



	real_pos = pos;



	if ((flags & BTREE_ITER_IS_EXTENTS) &&

	    bkey_cmp(pos, POS_MAX))

		real_pos = bpos_nosnap_successor(pos);



	trans_for_each_iter(trans, iter) {

		if (btree_iter_type(iter) != (flags & BTREE_ITER_TYPE))

			continue;
@@ -2037,8 +2050,8 @@ struct btree_iter *__bch2_trans_get_iter(struct btree_trans *trans, 
			continue;



		if (best) {

			int cmp = bkey_cmp(bpos_diff(best->real_pos, pos),

					   bpos_diff(iter->real_pos, pos));

			int cmp = bkey_cmp(bpos_diff(best->real_pos, real_pos),

					   bpos_diff(iter->real_pos, real_pos));



			if (cmp < 0 ||

			    ((cmp == 0 && btree_iter_keep(trans, iter))))
@@ -2048,6 +2061,13 @@ struct btree_iter *__bch2_trans_get_iter(struct btree_trans *trans, 
		best = iter;

	}



	trace_trans_get_iter(_RET_IP_, trans->ip,

			     btree_id,

			     &real_pos, locks_want,

			     best ? &best->real_pos : &pos_min,

			     best ? best->locks_want : 0,

			     best ? best->uptodate : BTREE_ITER_NEED_TRAVERSE);



	if (!best) {

		iter = btree_trans_iter_alloc(trans);

		bch2_btree_iter_init(trans, iter, btree_id);
@@ -2061,12 +2081,6 @@ struct btree_iter *__bch2_trans_get_iter(struct btree_trans *trans, 
	trans->iters_live	|= 1ULL << iter->idx;

	trans->iters_touched	|= 1ULL << iter->idx;



	if ((flags & BTREE_ITER_TYPE) != BTREE_ITER_NODES &&

	    btree_node_type_is_extents(btree_id) &&

	    !(flags & BTREE_ITER_NOT_EXTENTS) &&

	    !(flags & BTREE_ITER_ALL_SNAPSHOTS))

		flags |= BTREE_ITER_IS_EXTENTS;



	iter->flags = flags;



	iter->snapshot = pos.snapshot;
@@ -2098,7 +2112,7 @@ struct btree_iter *__bch2_trans_get_iter(struct btree_trans *trans, 
	iter->min_depth	= depth;



	bch2_btree_iter_set_pos(iter, pos);

	btree_iter_set_search_pos(iter, btree_iter_search_key(iter));

	btree_iter_set_search_pos(iter, real_pos);



	return iter;

}

fs/bcachefs/trace.h

+56 −0
Original line number Diff line number Diff line
@@ -528,6 +528,62 @@ TRACE_EVENT(copygc, 
		__entry->buckets_moved, __entry->buckets_not_moved)

);



TRACE_EVENT(trans_get_iter,

	TP_PROTO(unsigned long caller, unsigned long ip,

		 enum btree_id btree_id,

		 struct bpos *pos_want,

		 unsigned locks_want,

		 struct bpos *pos_found,

		 unsigned locks_found,

		 unsigned uptodate),

	TP_ARGS(caller, ip, btree_id,

		pos_want, locks_want,

		pos_found, locks_found,

		uptodate),



	TP_STRUCT__entry(

		__field(unsigned long,	caller			)

		__field(unsigned long,	ip			)

		__field(u8,		btree_id		)

		__field(u8,		uptodate		)

		__field(u8,		locks_want		)

		__field(u8,		locks_found		)

		__field(u64,		pos_want_inode		)

		__field(u64,		pos_want_offset		)

		__field(u32,		pos_want_snapshot	)

		__field(u64,		pos_found_inode		)

		__field(u64,		pos_found_offset	)

		__field(u32,		pos_found_snapshot	)

	),



	TP_fast_assign(

		__entry->caller			= caller;

		__entry->ip			= ip;

		__entry->btree_id		= btree_id;

		__entry->uptodate		= uptodate;

		__entry->pos_want_inode		= pos_want->inode;

		__entry->pos_want_offset	= pos_want->offset;

		__entry->pos_want_snapshot	= pos_want->snapshot;

		__entry->pos_found_inode	= pos_found->inode;

		__entry->pos_found_offset	= pos_found->offset;

		__entry->pos_found_snapshot	= pos_found->snapshot;

	),



	TP_printk("%ps %pS btree %u uptodate %u want %llu:%llu:%u locks %u found %llu:%llu:%u locks %u",

		  (void *) __entry->caller,

		  (void *) __entry->ip,

		  __entry->btree_id,

		  __entry->uptodate,

		  __entry->pos_want_inode,

		  __entry->pos_want_offset,

		  __entry->pos_want_snapshot,

		  __entry->locks_want,

		  __entry->pos_found_inode,

		  __entry->pos_found_offset,

		  __entry->pos_found_snapshot,

		  __entry->locks_found)

);



TRACE_EVENT(transaction_restart_ip,

	TP_PROTO(unsigned long caller, unsigned long ip),

	TP_ARGS(caller, ip),