On Fri, Jun 16, 2017 at 09:59:38AM -0600, Jens Axboe wrote: > >> Did you see v5? It adds enum write_hint and passes it all the way down, > >> until we transform them into rq/bio flags. > > > > Yes. But with all the way down I mean all the way down to the driver :) > > Only missing part is the request flags. And why make that any different > than the flags we already have now? It'd be trivial to pack the value > into the request flags as well, but I'm struggling to see the point of > that, honestly. > > Please expand on why you think changing the request flags to also > carry that value would be useful, as opposed to just mapping it when > we setup the request. If you have a valid concern I don't mind making > the change, but I just don't see one right now. Mostly so that we can pass the value down in one form through the whole stack. > How so? It's pretty straight forward. The only downside I see is that > we'll have a delay between seeing the first valid write hint and to > the time when nvme has it enabled. But that's so short, and in the > grander scheme of things, doesn't matter one bit. I'll take your word for that. To be honest I hope future standards won't make the mistake to come up with something as ugly as streams and just take something like our hints on a per-I/O basis..
