On Wed, Jun 11, 2025 at 08:23:34AM -0400, Mike Snitzer wrote: > On Wed, Jun 11, 2025 at 12:00:02AM -0700, Christoph Hellwig wrote: > > On Tue, Jun 10, 2025 at 04:57:36PM -0400, Mike Snitzer wrote: > > > IO must be aligned, otherwise it falls back to using buffered IO. > > > > > > RWF_DONTCACHE is _not_ currently used for misaligned IO (even when > > > nfsd/enable-dontcache=1) because it works against us (due to RMW > > > needing to read without benefit of cache), whereas buffered IO enables > > > misaligned IO to be more performant. > > > > This seems to "randomly" mix direct I/O and buffered I/O on a file. > > It isn't random, if the IO is DIO-aligned it uses direct I/O. Which as an I/O pattern does look pretty random :) > > But maybe also explain what this is trying to address to start with? > > Ha, I suspect you saw my too-many-words 0th patch header [1] and > ignored it? Solid feedback, I need to be more succinct and I'm > probably too close to this work to see the gaps in introduction and > justification but will refine, starting now: Well, I was mostly asking about the description for this patch in particular. Given that all the naming and the previous patches seemed to be about dontcache I/O having optional direct I/O in here looked really confusing.
