> -----Original Message----- > From: Christoph Hellwig <hch@xxxxxx> > Sent: Monday, October 14, 2024 8:21 AM > To: Jens Axboe <axboe@xxxxxxxxx> > Cc: Christoph Hellwig <hch@xxxxxx>; Javier Gonzalez <javier.gonz@xxxxxxxxxxx>; > Keith Busch <kbusch@xxxxxxxxxx>; Martin K. Petersen > <martin.petersen@xxxxxxxxxx>; Kanchan Joshi <joshi.k@xxxxxxxxxxx>; > hare@xxxxxxx; sagi@xxxxxxxxxxx; brauner@xxxxxxxxxx; viro@xxxxxxxxxxxxxxxxxx; > jack@xxxxxxx; jaegeuk@xxxxxxxxxx; bcrl@xxxxxxxxx; dhowells@xxxxxxxxxx; > bvanassche@xxxxxxx; asml.silence@xxxxxxxxx; linux-nvme@xxxxxxxxxxxxxxxxxxx; > linux-fsdevel@xxxxxxxxxxxxxxx; io-uring@xxxxxxxxxxxxxxx; linux- > block@xxxxxxxxxxxxxxx; linux-aio@xxxxxxxxx; gost.dev@xxxxxxxxxxx; > vishak.g@xxxxxxxxxxx > Subject: Re: [PATCH v7 0/3] FDP and per-io hints > > On Fri, Oct 11, 2024 at 11:08:26AM -0600, Jens Axboe wrote: > > > > I think that last argument is a straw man - for any kind of interface > > like this, we've ALWAYS just had the rule that any per-whatever > > overrides the generic setting. > > And exactly that is the problem. For file systems we can't support > that sanely. So IFF you absolutely want the per-I/O hints we need > an opt in by the file operations. I've said that at least twice > in this discussion before, but as everyone likes to have political > discussions instead of technical ones no one replied to that. Is it a way forward to add this in a new spin of the series - keeping the temperature mapping on the NVMe side? If not, what would be acceptable for a first version, before getting into adding a new interface to expose agnostic hints?