On Mon, Jan 29 2024 at 12:19P -0500, Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > While I'm sure this legacy application would love to not have to > change its code at all, I think we can all agree that we need to just > focus on how best to advise applications that have mixed workloads > accomplish efficient mmap+read of both sequential and random. > > To that end, I heard Dave clearly suggest 2 things: > > 1) update MADV/FADV_SEQUENTIAL to set file->f_ra.ra_pages to > bdi->io_pages, not bdi->ra_pages * 2 > > 2) Have the application first issue MADV_SEQUENTIAL to convey that for > the following MADV_WILLNEED is for sequential file load (so it is > desirable to use larger ra_pages) > > This overrides the default of bdi->io_pages and _should_ provide the > required per-file duality of control for readahead, correct? I meant "This overrides the default of bdi->ra_pages ..." ;)
