Re: [PATCH v3 3/7] block: add write-hint to stream-id conversion

From: Jan Kara
Date: Wed Apr 03 2019 - 05:36:15 EST


On Wed 03-04-19 07:35:08, Dave Chinner wrote:
> On Tue, Apr 02, 2019 at 11:20:44AM +0200, Jan Kara wrote:
> > On Mon 01-04-19 16:08:21, Dave Chinner wrote:
> > > On Fri, Mar 29, 2019 at 01:23:48PM +0530, Kanchan Joshi wrote:
> > > > + if(streamid > nr_streams)
> > > > + streamid = 0;
> > >
> > > So, basically, we'll compress all the kernel hints down to "no hint"
> > > if there are more user streams than the device supports?
> > >
> > > Surely we should be reserving a stream for the kernel hints separate
> > > from the user and "none" streams when we have limited device streams
> > > available...
> >
> > The question is what to do in a situation when the device has exactly as
> > many hints as we currently offer to userspace.
>
> Then do what we do now for that case. For every other case, the
> kernel should have reserved space and not get intermingled with
> userspace hints.

Yup, we are on the same page then.

Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR