On Tue, Jan 04, 2022 at 03:12:30PM -0800, Darrick J. Wong wrote: > As I see it, the problem here is that we're spending too much time > calling iomap_finish_page_writeback over and over and over, right? > > If we have a single page with a single mapping that fits in a single > bio, that means we call bio_add_page once, and on the other end we call > iomap_finish_page_writeback once. iomap_finish_page_writeback is called once per page, and the folio equivalent will be called once per folio, yes. But usually call bio_add_page mutliple times, due to the silly one block at a time loop in iomap_writepage_map. But that is someting we can easily fix.
