On Mon, Jan 28, 2019 at 04:47:09AM -0800, Jan Kara wrote: > On Fri 25-01-19 09:23:53, Keith Busch wrote: > > On Wed, Jan 09, 2019 at 09:00:57PM +0530, Kanchan Joshi wrote: > > > Towards supporing write-hints/streams for filesystem journal. > > > > > > > > > > > > Here is the v1 patch for background - > > > > > > https://marc.info/?l=linux-fsdevel&m=154444637519020&w=2 > > > > > > > > > > > > Changes since v1: > > > > > > - introduce four more hints for in-kernel use, as recommended by Dave > > > chinner > > > & Jens axboe. This isolates kernel-mode hints from user-mode ones. > > > > > > > The nvme driver disables streams if the controller doesn't support > > BLK_MAX_WRITE_HINT number of streams, so this series breaks the feature > > for controllers that only support up to 4. > > Right. Do you know if there are such controllers? Or are you just afraid > that there could be?
I've asked around, and the concensus I received is all currently support at least 8, but they couldn't say if that would be true for potential lower budget products. Can we implement a reasonable fallback to use what's available?
