bcachefs: Track maximum transaction memory

This patch
 - tracks maximum bch2_trans_kmalloc() memory used in btree_transaction_stats
 - makes it available in debugfs
 - switches bch2_trans_init() to using that for the amount of memory to
   preallocate, instead of the parameter passed in

This drastically reduces transaction restarts, and means we no longer
need to track this in the source code.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h
index f8b7434534eb..9e6c10dfa443 100644
--- a/fs/bcachefs/bcachefs.h
+++ b/fs/bcachefs/bcachefs.h
@@ -533,6 +533,7 @@ struct btree_transaction_stats {
 	struct bch2_time_stats	lock_hold_times;
 	struct mutex		lock;
 	unsigned		nr_max_paths;
+	unsigned		max_mem;
 	char			*max_paths_text;
 };