On Mon, Aug 12, 2024 at 08:11:57PM +0800, Zhang Yi wrote: > From: Zhang Yi <yi.zhang@xxxxxxxxxx> > > When doing page mkwrite, iomap_folio_mkwrite_iter() dirty the entire > folio by folio_mark_dirty() even the map length is shorter than one > folio. However, on the filesystem with more than one blocks per folio, > we'd better to only set counterpart block's dirty bit according to > iomap_length(), so open code folio_mark_dirty() and pass the correct > length. We shouldn't waste any time trying to optimise writing to files through mmap(). People have written papers about what a terrible programming model this is. eg https://db.cs.cmu.edu/mmap-cidr2022/ There are some programs that do it, but they are few and far between.
