On Wed, 8 Feb 2012 16:56:30 -0200, Eugeni Dodonov <eugeni at dodonov.net> wrote: > On Wed, Feb 8, 2012 at 16:06, Chris Wilson <chris at chris-wilson.co.uk> wrote: > > + /* Record the position of the start of the request so that > > + * should we detect the updated seqno part-way through the > > + * GPU processing the request, we never over-estimate the > > + * position of the head. > > + */ > > + request_ring_position = intel_ring_get_tail(ring); > > > Perhaps a stupid question within the bikeshedding spirit, but why do we > need intel_ring_get_tail()? Wouldn't just: > > request_ring_position = ring->tail; > > be self-explainable? Or some additional logic could be involved there at > some point? It is to try and preserve the illusion of a ringbuffer abstraction; the position of the request within the ring should be an internal detail of the ring but we are leaking it for our purposes. The use of a function there serves as a reminder of that leak (and easier to find than ring->tail) in the hope that someone will clean up the entire ringbuffer API and make the issue moot. -Chris -- Chris Wilson, Intel Open Source Technology Centre
