On Wed, 16 Sep 2020 at 16:58, Christian König <christian.koenig@xxxxxxx> wrote: > > Am 16.09.20 um 08:44 schrieb Thomas Hellström (Intel): > > > > On 9/16/20 6:28 AM, Dave Airlie wrote: > >> On Wed, 16 Sep 2020 at 14:19, Dave Airlie <airlied@xxxxxxxxx> wrote: > >>> On Wed, 16 Sep 2020 at 00:12, Christian König > >>> <ckoenig.leichtzumerken@xxxxxxxxx> wrote: > >>>> Hi Dave, > >>>> > >>>> I think we should just completely nuke ttm_tt_bind() and > >>>> ttm_tt_unbind() > >>>> and all of that. > >>>> > >>>> Drivers can to this from their move_notify() callback now instead. > >>> Good plan, I've put a bunch of rework into the same branch, > >>> > >>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fairlied%2Flinux%2Fcommits%2Fttm-half-baked-ideas&data=02%7C01%7Cchristian.koenig%40amd.com%7C3d6c9abffa5543a3881008d85a0c013c%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637358354912162169&sdata=kaR1uC3yLF%2F8AT1bgTpo%2F8An%2B0yywHZBAfXTD%2Ft%2BMb0%3D&reserved=0 > >>> > >>> > >>> but I've fried my brain a bit, I'm having trouble reconciling move > >>> notify and unbinding in the right places, I feel like I'm circling > >>> around the answer but haven't hit it yet. > >> drm/ttm: add unbind to move notify paths. > >> > >> In that tree is incorrect and I think where things fall apart, since > >> if we are moving TTM to VRAM that will unbind the TTM object from the > >> GTT at move notify time before the move has executed. > >> > >> I'm feeling a move_complete_notify might be an idea, but I'm wondering > >> if it's a bad idea. > >> > >> Dave. > > > > I don't know if this complicates things more, but move_notify was > > originally only thought to be an invalidation callback, and was never > > intended to drive any other actions in the driver than to invalidate > > various GPU bindings. > > And exactly that's what we need to change. See TTM or more precisely the > eviction handling should only manage where buffers are located and > notify that driver that something needs to move. > > Managing the whole binding/unbinding and actually moving the buffer > around inside TTM was a bad idea to begin with. > > In other words we have domains A, B, C.... and manage which BOs are > inside those domains and can be evicted when necessary. > > If the need arise to evict something the driver gets a notification > which BO was picked for eviction and acts accordingly. > > This means that the eviction_valuable, evict_flag, move_notify, binding, > unbinding etc... callbacks should be removed in the long term. I've pushed a few more WIP direction changes into my branch now, I think the fun bit I have to face next is splitting the move_accel_cleanup and pipeline move cleanups. but I'll keep in mind the goal of trying to get to a cleaner finished solution. Dave. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
