On Mon, 2008-08-04 at 22:25 -0400, John Stoffel wrote:
Right now, I'm working only on Intel integrated graphics, which doesn't
have any on-board memory. My thinking is that we'd best solve the
easiest case first before attempting the harder discrete graphics
driver. Plus, Intel pays me do do integrated graphics, so I have an
incentive.
Not that we haven't been thinking about how this plays with a discrete
card; we'll need to allocate backing store for any objects which are
placed in on-card memory in case we run out of on-card memory, and also
as a place to store objects when the system suspends. From the
perspective of shmem, it should be precisely the same; allocating
anonymous pages and handing them to the DRM driver to store video card
data.
Yup, I think you understand the situation fairly well. I've got a big
pile of pages sitting idle in the GTT which could be pulled out and
given back to the system. I like to keep a bunch around as the cost of
getting pages out of the CPU cache and bound to the GTT is non-trivial,
but if there's any memory pressure, the cost to free them is quite low.
--=20
keith.packard@intel.com