Alex Deucher wrote on 10.12.2016 23:03: > On Sat, Dec 10, 2016 at 4:52 PM, Kai Wasserbäch > <kai at dev.carbon-project.org> wrote: >> [Please CC me on all replies, I'm not subscribed to this list.] >> >> Dear Alex, >> Alex Deucher wrote on 10.12.2016 22:40: >>> On Fri, Dec 9, 2016 at 3:27 PM, Kai Wasserbäch >>> <kai at dev.carbon-project.org> wrote: >>>> [Please CC me on all replies, I'm not subscribed to this list.] >>>> >>>> Hey, >>>> I've been noticing that GLX_MESA_query_renderer reports less video memory when I >>>> use amdgpu for my Hawaii PRO GPU, than when I use radeon. Since I'm pretty happy >>>> with amdgpu (as I do not use HDMI audio) and it's the code, that gets active >>>> improvements, I'd like to stay with it, but having 40 MB of video memory >>>> "vanish" is not nice. >>>> With radeon GLX_MESA_query_renderer reports 4096 MB RAM (as expected, the R9 290 >>>> was sold/advertised with that), while I'm seeing 4056 MB with amdgpu (last >>>> tested kernel: 4.8.13). >>>> >>>> As I'm not sure, whether this is a bug or rather some always reserved memory >>>> area, which gets subtracted before reporting the available memory, I didn't file >>>> a bug report and rather am writing this e-mail. If it's a bug I'm happy to file >>>> the report against amdgpu. >>> >>> IIRC, the driver interfaces used to get the information exposed via >>> that extension are slightly different. radeon exposes the total >>> amount of vram while amdgpu reports the total amount of free vram. >>> The actual amount of free vram is probably pretty close. >> >> thanks for the explanation! >> >> But I'd like to point out that some of the automatic configuration tools shipped >> with games (and probably other programs) are deciding upon the reported values >> to which quality level they should default. Maybe reporting the theoretical VRAM >> might be better (you could always report the actual values through sysfs or some >> other channel)? > > I think all of the relevant info is available already, we'd just need > to update mesa to make both drivers report something consistent. The > extension isn't clear on whether it should be free memory or total > memory. The extension says: > > GLX_RENDERER_VIDEO_MEMORY_MESA 1 Number of megabytes of video > memory available to the renderer I agree, that the language of the spec isn't explicit in what should be reported. > That sort of implies free memory, but I guess most apps probably care > more about the overall memory size.
