On Wed, 3 Feb 2021 at 10:17, Daniel Vetter <daniel@xxxxxxxx> wrote: > > On Wed, Feb 3, 2021 at 9:51 AM Christian König <christian.koenig@xxxxxxx> wrote: > > > > Am 03.02.21 um 09:48 schrieb Daniel Vetter: > > > On Wed, Feb 3, 2021 at 9:36 AM Christian König <christian.koenig@xxxxxxx> wrote: > > >> Hi Daniel, > > >> > > >> this is not a deadlock, but rather a hardware lockup. > > > Are you sure? Ime getting stuck in dma_fence_wait has generally good > > > chance of being a dma_fence deadlock. GPU hang should never result in > > > a forever stuck dma_fence. > > > > Yes, I'm pretty sure. Otherwise the hardware clocks wouldn't go up like > > this. > > Maybe clarifying, could be both. TDR should notice and get us out of > this, but if there's a dma_fence deadlock and we can't re-emit or > force complete the pending things, then we're stuck for good. > -Daniel > > > Question is rather why we end up in the userptr handling for GFX? Our > > ROCm OpenCL stack shouldn't use this. > > > > > Daniel, can you pls re-hang your machine and then dump backtraces of > > > all tasks into dmesg with sysrq-t, and then attach that? Without all > > > the backtraces it's tricky to construct the full dependency chain of > > > what's going on. Also is this plain -rc6, not some more patches on > > > top? > > > > Yeah, that's still a good idea to have. Here the full backtrace dmesg logs after the hang: https://pastebin.com/raw/kzivm2L3 This is another dmesg log with the backtraces after SIGKILL the matrix process: (I didn't have the sysrq enable at the time): https://pastebin.com/raw/pRBwGcj1 > > > > Christian. > > > > > -Daniel > > > > > >> Which OpenCl stack are you using? > > >> > > >> Regards, > > >> Christian. > > >> > > >> Am 03.02.21 um 09:33 schrieb Daniel Gomez: > > >>> Hi all, > > >>> > > >>> I have a deadlock with the amdgpu mainline driver when running in parallel two > > >>> OpenCL applications. So far, we've been able to replicate it easily by executing > > >>> clinfo and MatrixMultiplication (from AMD opencl-samples). It's quite old the > > >>> opencl-samples so, if you have any other suggestion for testing I'd be very > > >>> happy to test it as well. > > >>> > > >>> How to replicate the issue: > > >>> > > >>> # while true; do /usr/bin/MatrixMultiplication --device gpu \ > > >>> --deviceId 0 -x 1000 -y 1000 -z 1000 -q -t -i 50; done > > >>> # while true; do clinfo; done > > >>> > > >>> Output: > > >>> > > >>> After a minute or less (sometimes could be more) I can see that > > >>> MatrixMultiplication and clinfo hang. In addition, with radeontop you can see > > >>> how the Graphics pipe goes from ~50% to 100%. Also the shader clocks > > >>> goes up from ~35% to ~96%. > > >>> > > >>> clinfo keeps printing: > > >>> ioctl(7, DRM_IOCTL_SYNCOBJ_WAIT, 0x7ffe46e5f950) = -1 ETIME (Timer expired) > > >>> > > >>> And MatrixMultiplication prints the following (strace) if you try to > > >>> kill the process: > > >>> > > >>> sched_yield() = 0 > > >>> futex(0x557e945343b8, FUTEX_WAIT_BITSET_PRIVATE|FUTEX_CLOCK_REALTIME, 0, > > >>> NULL, FUTEX_BITSET_MATCH_ANYstrace: Process 651 detached > > >>> <detached ...> > > >>> > > >>> After this, the gpu is not functional at all and you'd need a power cycle reset > > >>> to restore the system. > > >>> > > >>> Hardware info: > > >>> CPU: AMD Ryzen Embedded V1605B with Radeon Vega Gfx (8) @ 2.000GHz > > >>> GPU: AMD ATI Radeon Vega Series / Radeon Vega Mobile Series > > >>> > > >>> 03:00.0 VGA compatible controller: Advanced Micro Devices, Inc. > > >>> [AMD/ATI] Raven Ridge [Radeon Vega Series / Radeon Vega Mobile Series] > > >>> (rev 83) > > >>> DeviceName: Broadcom 5762 > > >>> Subsystem: Advanced Micro Devices, Inc. [AMD/ATI] Raven Ridge > > >>> [Radeon Vega Series / Radeon Vega Mobile Series] > > >>> Kernel driver in use: amdgpu > > >>> Kernel modules: amdgpu > > >>> > > >>> Linux kernel info: > > >>> > > >>> root@qt5222:~# uname -a > > >>> Linux qt5222 5.11.0-rc6-qtec-standard #2 SMP Tue Feb 2 09:41:46 UTC > > >>> 2021 x86_64 x86_64 x86_64 GNU/Linux > > >>> > > >>> By enabling the kernel locks stats I could see the MatrixMultiplication is > > >>> hanged in the amdgpu_mn_invalidate_gfx function: > > >>> > > >>> [ 738.359202] 1 lock held by MatrixMultiplic/653: > > >>> [ 738.359206] #0: ffff88810e364fe0 > > >>> (&adev->notifier_lock){+.+.}-{3:3}, at: > > >>> amdgpu_mn_invalidate_gfx+0x34/0xa0 [amdgpu] > > >>> > > >>> I can see in the the amdgpu_mn_invalidate_gfx function: the > > >>> dma_resv_wait_timeout_rcu uses wait_all (fences) and MAX_SCHEDULE_TIMEOUT so, I > > >>> guess the code gets stuck there waiting forever. According to the > > >>> documentation: "When somebody tries to invalidate the page tables we block the > > >>> update until all operations on the pages in question are completed, then those > > >>> pages are marked as accessed and also dirty if it wasn’t a read only access." > > >>> Looks like the fences are deadlocked and therefore, it never returns. Could it > > >>> be possible? any hint to where can I look to fix this? > > >>> > > >>> Thank you in advance. > > >>> > > >>> Here the full dmesg output: > > >>> > > >>> [ 738.337726] INFO: task MatrixMultiplic:653 blocked for more than 122 seconds. > > >>> [ 738.344937] Not tainted 5.11.0-rc6-qtec-standard #2 > > >>> [ 738.350384] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" > > >>> disables this message. > > >>> [ 738.358240] task:MatrixMultiplic state:D stack: 0 pid: 653 > > >>> ppid: 1 flags:0x00004000 > > >>> [ 738.358254] Call Trace: > > >>> [ 738.358261] ? dma_fence_default_wait+0x1eb/0x230 > > >>> [ 738.358276] __schedule+0x370/0x960 > > >>> [ 738.358291] ? dma_fence_default_wait+0x117/0x230 > > >>> [ 738.358297] ? dma_fence_default_wait+0x1eb/0x230 > > >>> [ 738.358305] schedule+0x51/0xc0 > > >>> [ 738.358312] schedule_timeout+0x275/0x380 > > >>> [ 738.358324] ? dma_fence_default_wait+0x1eb/0x230 > > >>> [ 738.358332] ? mark_held_locks+0x4f/0x70 > > >>> [ 738.358341] ? dma_fence_default_wait+0x117/0x230 > > >>> [ 738.358347] ? lockdep_hardirqs_on_prepare+0xd4/0x180 > > >>> [ 738.358353] ? _raw_spin_unlock_irqrestore+0x39/0x40 > > >>> [ 738.358362] ? dma_fence_default_wait+0x117/0x230 > > >>> [ 738.358370] ? dma_fence_default_wait+0x1eb/0x230 > > >>> [ 738.358375] dma_fence_default_wait+0x214/0x230 > > >>> [ 738.358384] ? dma_fence_release+0x1a0/0x1a0 > > >>> [ 738.358396] dma_fence_wait_timeout+0x105/0x200 > > >>> [ 738.358405] dma_resv_wait_timeout_rcu+0x1aa/0x5e0 > > >>> [ 738.358421] amdgpu_mn_invalidate_gfx+0x55/0xa0 [amdgpu] > > >>> [ 738.358688] __mmu_notifier_release+0x1bb/0x210 > > >>> [ 738.358710] exit_mmap+0x2f/0x1e0 > > >>> [ 738.358723] ? find_held_lock+0x34/0xa0 > > >>> [ 738.358746] mmput+0x39/0xe0 > > >>> [ 738.358756] do_exit+0x5c3/0xc00 > > >>> [ 738.358763] ? find_held_lock+0x34/0xa0 > > >>> [ 738.358780] do_group_exit+0x47/0xb0 > > >>> [ 738.358791] get_signal+0x15b/0xc50 > > >>> [ 738.358807] arch_do_signal_or_restart+0xaf/0x710 > > >>> [ 738.358816] ? lockdep_hardirqs_on_prepare+0xd4/0x180 > > >>> [ 738.358822] ? _raw_spin_unlock_irqrestore+0x39/0x40 > > >>> [ 738.358831] ? ktime_get_mono_fast_ns+0x50/0xa0 > > >>> [ 738.358844] ? amdgpu_drm_ioctl+0x6b/0x80 [amdgpu] > > >>> [ 738.359044] exit_to_user_mode_prepare+0xf2/0x1b0 > > >>> [ 738.359054] syscall_exit_to_user_mode+0x19/0x60 > > >>> [ 738.359062] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > >>> [ 738.359069] RIP: 0033:0x7f6b89a51887 > > >>> [ 738.359076] RSP: 002b:00007f6b82b54b18 EFLAGS: 00000246 ORIG_RAX: > > >>> 0000000000000010 > > >>> [ 738.359086] RAX: fffffffffffffe00 RBX: 00007f6b82b54b50 RCX: 00007f6b89a51887 > > >>> [ 738.359091] RDX: 00007f6b82b54b50 RSI: 00000000c02064c3 RDI: 0000000000000007 > > >>> [ 738.359096] RBP: 00000000c02064c3 R08: 0000000000000003 R09: 00007f6b82b54bbc > > >>> [ 738.359101] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000165a0bc00 > > >>> [ 738.359106] R13: 0000000000000007 R14: 0000000000000001 R15: 0000000000000000 > > >>> [ 738.359129] > > >>> Showing all locks held in the system: > > >>> [ 738.359141] 1 lock held by khungtaskd/54: > > >>> [ 738.359148] #0: ffffffff829f6840 (rcu_read_lock){....}-{1:2}, at: > > >>> debug_show_all_locks+0x15/0x183 > > >>> [ 738.359187] 1 lock held by systemd-journal/174: > > >>> [ 738.359202] 1 lock held by MatrixMultiplic/653: > > >>> [ 738.359206] #0: ffff88810e364fe0 > > >>> (&adev->notifier_lock){+.+.}-{3:3}, at: > > >>> amdgpu_mn_invalidate_gfx+0x34/0xa0 [amdgpu] > > >>> > > >>> Daniel > > >> _______________________________________________ > > >> dri-devel mailing list > > >> dri-devel@xxxxxxxxxxxxxxxxxxxxx > > >> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&data=04%7C01%7Cchristian.koenig%40amd.com%7C81203e5bac5841b8e5a108d8c82087a9%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637479389339295622%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=RDSxD6OqD8HaOA2VnNfbJwLnKzhCLgOr5SVLjLF91bA%3D&reserved=0 > > > > > > > > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
