Hi! Rafał and I discovered that page writeback on UBIFS behaves different since v5.14. When a simple write, such as "echo foo > /mnt/ubibfs/bar.txt", happens it takes a few seconds until writeback calls ubifs_writepage(). Before commit ab19939a6a50 ("mm/page-writeback: Fix performance when BDI's share of ratio is 0.") it was 30 seconds (vm.dirty_expire_centisecs), after this change it happens after 5 seconds (vm.dirty_writeback_centisecs). Is this expected? Just want to make sure that the said commit didn't uncover an UBIFS issue. Thanks, //richard