Re: amdgpu doesn't do implicit sync, requires drivers to do it in IBs

2020-05-29 Thread Christian König
Am 28.05.20 um 21:35 schrieb Marek Olšák: On Thu, May 28, 2020 at 2:12 PM Christian König mailto:christian.koe...@amd.com>> wrote: Am 28.05.20 um 18:06 schrieb Marek Olšák: On Thu, May 28, 2020 at 10:40 AM Christian König mailto:christian.koe...@amd.com>> wrote: Am 28.05.2

Re: amdgpu doesn't do implicit sync, requires drivers to do it in IBs

2020-05-28 Thread Marek Olšák
On Thu, May 28, 2020 at 2:12 PM Christian König wrote: > Am 28.05.20 um 18:06 schrieb Marek Olšák: > > On Thu, May 28, 2020 at 10:40 AM Christian König > wrote: > >> Am 28.05.20 um 12:06 schrieb Michel Dänzer: >> > On 2020-05-28 11:11 a.m., Christian König wrote: >> >> Well we still need implici

Re: amdgpu doesn't do implicit sync, requires drivers to do it in IBs

2020-05-28 Thread Christian König
Am 28.05.20 um 18:06 schrieb Marek Olšák: On Thu, May 28, 2020 at 10:40 AM Christian König mailto:christian.koe...@amd.com>> wrote: Am 28.05.20 um 12:06 schrieb Michel Dänzer: > On 2020-05-28 11:11 a.m., Christian König wrote: >> Well we still need implicit sync [...] > Yeah, th

Re: amdgpu doesn't do implicit sync, requires drivers to do it in IBs

2020-05-28 Thread Marek Olšák
On Thu, May 28, 2020 at 10:40 AM Christian König wrote: > Am 28.05.20 um 12:06 schrieb Michel Dänzer: > > On 2020-05-28 11:11 a.m., Christian König wrote: > >> Well we still need implicit sync [...] > > Yeah, this isn't about "we don't want implicit sync", it's about "amdgpu > > doesn't ensure la

Re: amdgpu doesn't do implicit sync, requires drivers to do it in IBs

2020-05-28 Thread Christian König
Am 28.05.20 um 12:06 schrieb Michel Dänzer: On 2020-05-28 11:11 a.m., Christian König wrote: Well we still need implicit sync [...] Yeah, this isn't about "we don't want implicit sync", it's about "amdgpu doesn't ensure later jobs fully see the effects of previous implicitly synced jobs", requi

Re: amdgpu doesn't do implicit sync, requires drivers to do it in IBs

2020-05-28 Thread Michel Dänzer
On 2020-05-28 11:11 a.m., Christian König wrote: > Well we still need implicit sync [...] Yeah, this isn't about "we don't want implicit sync", it's about "amdgpu doesn't ensure later jobs fully see the effects of previous implicitly synced jobs", requiring userspace to do pessimistic flushing.

Re: amdgpu doesn't do implicit sync, requires drivers to do it in IBs

2020-05-28 Thread Christian König
Well we still need implicit sync or otherwise the GPU scheduler would pick up the jobs in the wrong order. See without this when we have the following sequence of submission: Client IB1 using buffer A Client IB2 X IB1 using buffer A We could end up with the execution order X IB1 using buffer

Re: amdgpu doesn't do implicit sync, requires drivers to do it in IBs

2020-05-25 Thread Marek Olšák
If a user mode driver is changed to rely on the existence of implicit sync, it results in corruption and flickering as reported here: https://gitlab.freedesktop.org/mesa/mesa/-/issues/2950 Marek On Mon, May 25, 2020 at 6:05 PM Marek Olšák wrote: > Hi Christian, > > Bas and Michel wanted to disc