On Wed, Apr 01, 2015 at 05:07:25PM +0100, Tvrtko Ursulin wrote: > > On 04/01/2015 04:42 PM, Chris Wilson wrote: > >On Wed, Apr 01, 2015 at 04:14:52PM +0100, Tvrtko Ursulin wrote: > >>+ /* Re-exec with padding set. */ > >>+ igt_assert(exec(fd, eb_handles, pad_to_size, offsets) == 0); > > > >The crux of the test is that we generate two objects such that > > > >B_offset = A_offset + A_size > > > >and then tell the kernel that A is actually 2*size (A_pad_to_size) > > > >>+ if (offsets[1] > offsets[0]) > >>+ distance = offsets[1] - offsets[0]; > >>+ else > >>+ distance = offsets[0] - offsets[1]; > > > >The assertion I feel should only be that > > > >B_offset + B_size <= A_offset && B_offset >= A_offset + A_pad_to_size > > I don't get this. B starts after A + padding, but B ends before A? s/&&/||/ > >i.e. that they are now disjoint. > > > >Your test is valid nevertheless, it is the ordering of the objects that > >is confusing. > > > >Hmm, can you loop until B_offset == A_offset + A_size such that we don't > >have the confusion with order? And even assert that A_offset is > >unchanged (though that smells like a little to much internal knowledge > >leaking through, it is a desirable property of the allocator though - no > >unnecessarily eviction) afterwards. > > > >Do you agree that losing the handling of negative distances will make > >the test simpler to understand (at the expense of doing more work in the > >setup)? > > I thought my test logic is pretty straightforward: > > 1. Find two objects next to each other. > 2. Add padding on the "lower" (addressed) object. > 3. Ensure objects are now apart at least what the padding is. What should happen is: Initial layout: | ||aa||bb| batch A B (B_offset == A_offset + PAGE) We then submit an execbuf with A_pad_to_size = 2*PAGE, the kernel will unbind A, keep B, then bind A (given an empty GTT): | |xxxx|bb||aaaaaa| batch B A but the distance here is just 1 PAGE. Then if B_pad_to_size is set to 2*PAGE: | |xxxxxxxx|aaaaaa||bbbbbb| batch A B If both are initially set to pad_to_size = 2*PAGE, we should see something like: | ||aaaaaa||bbbbbb| batch A B Given that the assertion should just be that the new objects do not overlap assuming their size is now pad_to_size. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
