On Mon, Apr 17, 2017 at 11:55 AM, Michel Dänzer <michel at daenzer.net> wrote: > On 17/04/17 07:58 AM, Marek Olšák wrote: >> On Fri, Apr 14, 2017 at 12:14 PM, Michel Dänzer <michel at daenzer.net> wrote: >>> On 04/04/17 05:11 AM, Marek Olšák wrote: >>>> On Fri, Mar 31, 2017 at 5:24 AM, Michel Dänzer <michel at daenzer.net> wrote: >>>>> On 30/03/17 07:03 PM, Michel Dänzer wrote: >>>>>> On 25/03/17 01:33 AM, Marek Olšák wrote: >>>>>>> Hi, >>>>>>> >>>>>>> I'm sharing this idea here, because it's something that has been >>>>>>> decreasing our performance a lot recently, for example: >>>>>>> http://openbenchmarking.org/prospect/1703011-RI-RADEONDIR06/7b7668cfc109d1c3dc27e871c8aea71ca13f23fa >>>>>> >>>>>> The attached proof-of-concept patch (on top of Christian's "CPU mapping >>>>>> of split VRAM buffers" series, ported from radeon) results in 145.05 fps >>>>>> on my Tonga. >>>>> >>>>> I get the same result without my or Christian's patches though, with >>>>> 4.11 based DRM or amd-staging-4.9. So I guess I just can't reproduce the >>>>> problem with this test. Are there any other tests for it? >>>> >>>> It's random. Sometimes the benchmark runs OK, other times it's slow. >>>> You can easily see the difference but observing how smooth it is. The >>>> visible VRAM evictions result in constant 100-200ms stalls but not >>>> every frame, which feels like the frame rate is much lower than it >>>> actually is. >>>> >>>> Make sure your graphics details are maxed out. The best score I can >>>> get with my rig is 70 fps. (Fiji & Core i5 3570) >>> >>> I'm getting around 53-54 fps at Ultra with Tonga, both with Mesa 13.0.6 >>> and Git. >>> >>> Have you tried if Christian's patches for CPU access to split VRAM >>> buffers help? I can imagine that forcing contiguous VRAM buffers for CPU >>> access could cause lots of other BOs to be unnecessarily evicted from >>> VRAM, if at least one of their fragments happens to be in the CPU >>> visible part of VRAM. >> >> I've finally tested latest amd-staging-4.9 and I'm very pleased. For >> the first time, the Deus Ex benchmark has almost no hiccups. I've >> never seen it so smooth. At one point, the MB/s BO move rate increase >> to 200MB/s, stayed there for a couple of seconds, and then it dropped >> to 0 again. The frame rate was OK-ish, so I guess the moves didn't >> happen all at once. I also tested DiRT Rally and I haven't been able >> to reproduce the low FPS with the consistently-high BO move rate that >> I saw several months ago. >> >> We could do some move throttling there for sure, but it's much better >> than it ever was. > > That's great to hear. If you get a chance, it would be interesting if > the attached updated patch improves things even more for you. (The patch > I attached previously couldn't work as intended, this one at least might :) Frogging101 on IRC noticed that we get a ton of TTM BO moves due to visible VRAM thrashing and Michel's patch doesn't help. His kernel is up to date with amd-staging. It looks like the only option left is my original plan: BO move throttling for visible VRAM by redirecting mapped buffers to GTT and not allowing them to go back to VRAM if some counter is too high. Opinions? Marek
