On Thu, Mar 05, 2015 at 02:56:52AM +0000, Song, Ruiling wrote: > Hi Daniel, > > OpenCL language support NULL pointer, using zero as the NULL pointer is > the obvious way. That is zero will be treated as invalid address. Then > it requires drm won't allocate zero to drm buffer. And David in CC > list has help us make a patch, please see attached. The logic is only > for ppgtt, and he said zero offset is used under ggtt. My question is > what is offset zero used under ggtt? Will it make sure zero is not > allocatable to drm buffer object? The code in i915_gem_execbuf.c already supports an optional bias to avoid putting a buffer into the first few kb. See __EXEC_OBJECT_NEEDS_BIAS. I suggest you expose this to userspace, which also address your issue that you didn't add an abi revision flag. And since this is abi I need open-source userspace and all that. Thanks, Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
