btrfs: extent-tree: Add trace events for space info numbers update
Add trace event for update_bytes_pinned() and update_bytes_may_use() to
detect underflow better.
The output would be something like (only showing data part):
## Buffered write start, 16K total ##
2255.954 xfs_io/860 btrfs:update_bytes_may_use:(nil)U: type=DATA old=0 diff=4096
2257.169 sudo/860 btrfs:update_bytes_may_use:(nil)U: type=DATA old=4096 diff=4096
2257.346 sudo/860 btrfs:update_bytes_may_use:(nil)U: type=DATA old=8192 diff=4096
2257.542 sudo/860 btrfs:update_bytes_may_use:(nil)U: type=DATA old=12288 diff=4096
## Delalloc start ##
3727.853 kworker/u8:3-e/700 btrfs:update_bytes_may_use:(nil)U: type=DATA old=16384 diff=-16384
## Space cache update ##
3733.132 sudo/862 btrfs:update_bytes_may_use:(nil)U: type=DATA old=0 diff=65536
3733.169 sudo/862 btrfs:update_bytes_may_use:(nil)U: type=DATA old=65536 diff=-65536
3739.868 sudo/862 btrfs:update_bytes_may_use:(nil)U: type=DATA old=0 diff=65536
3739.891 sudo/862 btrfs:update_bytes_may_use:(nil)U: type=DATA old=65536 diff=-65536
These two trace events will allow bcc tool to probe btrfs_space_info
changes and detect underflow with more details (e.g. backtrace for each
update).
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h
index f9eff01..2f6a669 100644
--- a/include/trace/events/btrfs.h
+++ b/include/trace/events/btrfs.h
@@ -29,6 +29,7 @@ struct btrfs_qgroup_extent_record;
struct btrfs_qgroup;
struct extent_io_tree;
struct prelim_ref;
+struct btrfs_space_info;
TRACE_DEFINE_ENUM(FLUSH_DELAYED_ITEMS_NR);
TRACE_DEFINE_ENUM(FLUSH_DELAYED_ITEMS);
@@ -2091,6 +2092,45 @@ DEFINE_BTRFS_LOCK_EVENT(btrfs_try_tree_read_lock);
DEFINE_BTRFS_LOCK_EVENT(btrfs_try_tree_write_lock);
DEFINE_BTRFS_LOCK_EVENT(btrfs_tree_read_lock_atomic);
+DECLARE_EVENT_CLASS(btrfs__space_info_update,
+
+ TP_PROTO(struct btrfs_fs_info *fs_info,
+ struct btrfs_space_info *sinfo, u64 old, s64 diff),
+
+ TP_ARGS(fs_info, sinfo, old, diff),
+
+ TP_STRUCT__entry_btrfs(
+ __field( u64, type )
+ __field( u64, old )
+ __field( s64, diff )
+ ),
+
+ TP_fast_assign_btrfs(fs_info,
+ __entry->type = sinfo->flags;
+ __entry->old = old;
+ __entry->diff = diff;
+ ),
+ TP_printk_btrfs("type=%s old=%llu diff=%lld",
+ __print_flags(__entry->type, "|", BTRFS_GROUP_FLAGS),
+ __entry->old, __entry->diff)
+);
+
+DEFINE_EVENT(btrfs__space_info_update, update_bytes_may_use,
+
+ TP_PROTO(struct btrfs_fs_info *fs_info,
+ struct btrfs_space_info *sinfo, u64 old, s64 diff),
+
+ TP_ARGS(fs_info, sinfo, old, diff)
+);
+
+DEFINE_EVENT(btrfs__space_info_update, update_bytes_pinned,
+
+ TP_PROTO(struct btrfs_fs_info *fs_info,
+ struct btrfs_space_info *sinfo, u64 old, s64 diff),
+
+ TP_ARGS(fs_info, sinfo, old, diff)
+);
+
#endif /* _TRACE_BTRFS_H */
/* This part must be outside protection */