On Thu, Jun 18, 2015 at 07:07:46PM +0100, Dave Gordon wrote: > On 18/06/15 13:10, Chris Wilson wrote: > > On Thu, Jun 18, 2015 at 12:49:55PM +0100, Dave Gordon wrote: > >> On 17/06/15 13:02, Daniel Vetter wrote: > >>> Domain handling is required for all gem objects, and the resulting bugs if > >>> you don't for one-off objects are absolutely no fun to track down. > >> > >> Is it not the case that the new object returned by > >> i915_gem_alloc_object() is > >> (a) of a type that can be mapped into the GTT, and > >> (b) initially in the CPU domain for both reading and writing? > >> > >> So AFAICS the allocate-and-fill function I'm describing (to appear in > >> next patch series respin) doesn't need any further domain handling. > > > > A i915_gem_object_create_from_data() is a reasonable addition, and I > > suspect it will make the code a bit more succinct. > > I shall adopt this name for it :) > > > Whilst your statement is true today, calling set_domain is then a no-op, > > and helps document how you use the object and so reduces the likelihood > > of us introducing bugs in the future. > > -Chris > > So here's the new function ... where should the set-to-cpu-domain go? > After the pin_pages and before the sg_copy_from_buffer? Either, since the domain will not change whilst you have the lock, but if you do it before get_pages() you will have a slightly easier error path. Part of the reason why I want a function like this is so that I can replace it with a stolen object and so need to write the data through a temporary GGTT mapping. Speak now if you need more flags to the function to prevent certain classes of objects being created. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
