| Bug ID | 96360 |
|---|---|
| Summary | VM fault with kernel 4.7-rc1 on Alien: Isolation |
| Product | DRI |
| Version | DRI git |
| Hardware | Other |
| OS | All |
| Status | NEW |
| Severity | normal |
| Priority | medium |
| Component | DRM/Radeon |
| Assignee | dri-devel@lists.freedesktop.org |
| Reporter | alexandre.f.demers@gmail.com |
Created attachment 124312 [de=
tails]
VM faults in dmesg triggered by Alien: Isolation
Hi,
I've recently begun playing Alien: Isolation now that the compute shaders a=
re
available when combining latest Mesa with a 4.7-git kernel. However, my
computer freezes after sometime. Poking dmesg got me a repeating VM fault w=
hich
goes on as long as I'm in the game (playing, not the menu or while loading).
Setup:
GPU -> R9 280X
Kernel -> 4.7-rc1
Distribution -> Archlinux 64
Mesa, drm, ddx -> using latest code from git repositories
I'll try with a 4.6 kernel to see if this bug was introduced in or exposed =
by
the 4.7 branch.=20
Attaching dmesg
So this is the commit that exposes the bug. 3d02b7fee9c3ece1746f5b06c4143b511383fc6b is the first bad commit commit 3d02b7fee9c3ece1746f5b06c4143b511383fc6b Author: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl> Date: Fri Apr 15 02:47:49 2016 +0200 drm/radeon: Allow setting shader registers using DMA/COPY packet3 on SI. Mesa uses a COPY_DATA packet to copy the grid size for indirect dispatc= hes into COMPUTE_USER_DATA_*. Setting those registers with a SET_SH_REG packet is allowed, not allowi= ng them with other packets seems like an oversight. v2: Clarify commit message. Signed-off-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> :040000 040000 ec4d58f4c4e5bd746474776c852a7c70763183a7 8ba67a00f061b454d1600838bf620e1e937e9461 M drivers
| What | Removed | Added |
|---|---|---|
| Summary | VM fault with kernel 4.7-rc1 on Alien: Isolation | [bisected] VM fault with kernel 4.7-rc1 on Alien: Isolation |
| What | Removed | Added |
|---|---|---|
| Summary | [bisected] VM fault with kernel 4.7-rc1 on Alien: Isolation | [bisected: 3d02b7] VM fault with kernel 4.7-rc1 on Alien: Is= olation |
Still a problem with today's latest mesa and kernel 4.7-rc2.
Can you provide an apitrace that reproduces the VM faults?
(In reply to Nicolai H=C3=A4hnle from comment #3) > Can you provide an apitrace that reproduces the = VM faults? I'll do that later. However, it may end up as a big apitrace since it takes= a lot of time before being able to actually play de game, which is when the VM faults appear. I'll figure out a way of putting a link.
Thanks, that would be much appreciated. Most people tend to us= e Google Drive - I've downloaded GB-sized traces from there.
And here is the trace that you can download from Google Drive = (I hope it works correctly): https://drive.google.com/open?id=3D0Bw_tZdWsNa4BV0VKMGVaeFBDaEE
Thanks! No VM faults here on Tonga, so this may be specific to= SI. Do you get VM faults in dmesg when you play the trace back on your system?
(In reply to Nicolai H=C3=A4hnle from comment #7) > Thanks! No VM faults here on Tonga, so this may = be specific to SI. Do you > get VM faults in dmesg when you play the trace back on your system? Yes it does, I just tested it with the trace I've shared with you.
(In reply to Nicolai H=C3=A4hnle from comment #7) > Thanks! No VM faults here on Tonga, so this may = be specific to SI. Do you > get VM faults in dmesg when you play the trace back on your system? Anything I can provide you with? Any specific test or steps?
No, thank you. I can reproduce this on a Verde, so it does see= m to be SI-specific (perhaps also CI) or perhaps a radeon vs. amdgpu issue. I've seen a VM fault even with GALLIUM_DDEBUG=3D800 (i.e. frequent flushes) happen at 901138 @3 glDispatchCompute(num_groups_x =3D 128, num_groups_y =3D 2, n= um_groups_z =3D 1)
Created attachment 124514 = [details] [review] preliminary patch Problem understood - we're generating bad shader code - though I still need= to double-check all the possible corner cases. In the meantime, the attached patch for LLVM should fix Alien: Isolation.
| What | Removed | Added |
|---|---|---|
| Status | NEW | RESOLVED |
| Resolution | --- | FIXED |
(In reply to Nicolai H=C3=A4hnle from comment #12) > Fixed in LLVM r272761. Thank you, I'll test it later today.