On Wed, Jun 25, 2014 at 11:51:33AM +0100, Damien Lespiau wrote: > (This is not necessarily things one would need to take into account for > this work, just a few thoughts). > > One thing I'm wondering is how fitting the "size" parameter really is > when talking about inherently 2D buffers. > > For instance, let's take a Y-tiled texture with MIPLAYOUT_RIGHT, if we > want to allocate mip map levels 0 and 1, and use the ioctl "naively" to > reserve the LOD1 region in one go, we'll end up over allocating the > space below LOD1 (if I'm not mistaken that is). > > This can be mitigated by several calls to this fallocate ioctl, to > reserve columns of pages (in the case above, columns for the LOD1 > region). > > So, how about trying to reduce this ioctl overhead by providing a list > of (start, length) in the ioctl structure? One more thing to factor in is (let's assume one future hardware will support that): https://www.opengl.org/registry/specs/ARB/sparse_texture.txt So maybe what we really want is to be able to specify region of pages that could be specified in (x, y, width, height, stride) ? (idea popped when talking to Neil Roberts (I now have someone working on Mesa in the office). -- Damien _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
