[PATCH] drm/amdgpu: Fix recursive locking warning

Fri Feb 4 07:13:58 UTC 2022

Am 04.02.22 um 04:11 schrieb Rajneesh Bhardwaj:
> Noticed the below warning while running a pytorch workload on vega10
> GPUs. Change to trylock to avoid conflicts with already held reservation
> locks.
>
> [  +0.000003] WARNING: possible recursive locking detected
> [  +0.000003] 5.13.0-kfd-rajneesh #1030 Not tainted
> [  +0.000004] --------------------------------------------
> [  +0.000002] python/4822 is trying to acquire lock:
> [  +0.000004] ffff932cd9a259f8 (reservation_ww_class_mutex){+.+.}-{3:3},
> at: amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
> [  +0.000203]
>                but task is already holding lock:
> [  +0.000003] ffff932cbb7181f8 (reservation_ww_class_mutex){+.+.}-{3:3},
> at: ttm_eu_reserve_buffers+0x270/0x470 [ttm]
> [  +0.000017]
>                other info that might help us debug this:
> [  +0.000002]  Possible unsafe locking scenario:
>
> [  +0.000003]        CPU0
> [  +0.000002]        ----
> [  +0.000002]   lock(reservation_ww_class_mutex);
> [  +0.000004]   lock(reservation_ww_class_mutex);
> [  +0.000003]
>                 *** DEADLOCK ***
>
> [  +0.000002]  May be due to missing lock nesting notation
>
> [  +0.000003] 7 locks held by python/4822:
> [  +0.000003]  #0: ffff932c4ac028d0 (&process->mutex){+.+.}-{3:3}, at:
> kfd_ioctl_map_memory_to_gpu+0x10b/0x320 [amdgpu]
> [  +0.000232]  #1: ffff932c55e830a8 (&info->lock#2){+.+.}-{3:3}, at:
> amdgpu_amdkfd_gpuvm_map_memory_to_gpu+0x64/0xf60 [amdgpu]
> [  +0.000241]  #2: ffff932cc45b5e68 (&(*mem)->lock){+.+.}-{3:3}, at:
> amdgpu_amdkfd_gpuvm_map_memory_to_gpu+0xdf/0xf60 [amdgpu]
> [  +0.000236]  #3: ffffb2b35606fd28
> (reservation_ww_class_acquire){+.+.}-{0:0}, at:
> amdgpu_amdkfd_gpuvm_map_memory_to_gpu+0x232/0xf60 [amdgpu]
> [  +0.000235]  #4: ffff932cbb7181f8
> (reservation_ww_class_mutex){+.+.}-{3:3}, at:
> ttm_eu_reserve_buffers+0x270/0x470 [ttm]
> [  +0.000015]  #5: ffffffffc045f700 (*(sspp++)){....}-{0:0}, at:
> drm_dev_enter+0x5/0xa0 [drm]
> [  +0.000038]  #6: ffff932c52da7078 (&vm->eviction_lock){+.+.}-{3:3},
> at: amdgpu_vm_bo_update_mapping+0xd5/0x4f0 [amdgpu]
> [  +0.000195]
>                stack backtrace:
> [  +0.000003] CPU: 11 PID: 4822 Comm: python Not tainted
> 5.13.0-kfd-rajneesh #1030
> [  +0.000005] Hardware name: GIGABYTE MZ01-CE0-00/MZ01-CE0-00, BIOS F02
> 08/29/2018
> [  +0.000003] Call Trace:
> [  +0.000003]  dump_stack+0x6d/0x89
> [  +0.000010]  __lock_acquire+0xb93/0x1a90
> [  +0.000009]  lock_acquire+0x25d/0x2d0
> [  +0.000005]  ? amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
> [  +0.000184]  ? lock_is_held_type+0xa2/0x110
> [  +0.000006]  ? amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
> [  +0.000184]  __ww_mutex_lock.constprop.17+0xca/0x1060
> [  +0.000007]  ? amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
> [  +0.000183]  ? lock_release+0x13f/0x270
> [  +0.000005]  ? lock_is_held_type+0xa2/0x110
> [  +0.000006]  ? amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
> [  +0.000183]  amdgpu_bo_release_notify+0xc4/0x160 [amdgpu]
> [  +0.000185]  ttm_bo_release+0x4c6/0x580 [ttm]
> [  +0.000010]  amdgpu_bo_unref+0x1a/0x30 [amdgpu]
> [  +0.000183]  amdgpu_vm_free_table+0x76/0xa0 [amdgpu]
> [  +0.000189]  amdgpu_vm_free_pts+0xb8/0xf0 [amdgpu]
> [  +0.000189]  amdgpu_vm_update_ptes+0x411/0x770 [amdgpu]
> [  +0.000191]  amdgpu_vm_bo_update_mapping+0x324/0x4f0 [amdgpu]
> [  +0.000191]  amdgpu_vm_bo_update+0x251/0x610 [amdgpu]
> [  +0.000191]  update_gpuvm_pte+0xcc/0x290 [amdgpu]
> [  +0.000229]  ? amdgpu_vm_bo_map+0xd7/0x130 [amdgpu]
> [  +0.000190]  amdgpu_amdkfd_gpuvm_map_memory_to_gpu+0x912/0xf60
> [amdgpu]
> [  +0.000234]  kfd_ioctl_map_memory_to_gpu+0x182/0x320 [amdgpu]
> [  +0.000218]  kfd_ioctl+0x2b9/0x600 [amdgpu]
> [  +0.000216]  ? kfd_ioctl_unmap_memory_from_gpu+0x270/0x270 [amdgpu]
> [  +0.000216]  ? lock_release+0x13f/0x270
> [  +0.000006]  ? __fget_files+0x107/0x1e0
> [  +0.000007]  __x64_sys_ioctl+0x8b/0xd0
> [  +0.000007]  do_syscall_64+0x36/0x70
> [  +0.000004]  entry_SYSCALL_64_after_hwframe+0x44/0xae
> [  +0.000007] RIP: 0033:0x7fbff90a7317
> [  +0.000004] Code: b3 66 90 48 8b 05 71 4b 2d 00 64 c7 00 26 00 00 00
> 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f
> 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 41 4b 2d 00 f7 d8 64 89 01 48
> [  +0.000005] RSP: 002b:00007fbe301fe648 EFLAGS: 00000246 ORIG_RAX:
> 0000000000000010
> [  +0.000006] RAX: ffffffffffffffda RBX: 00007fbcc402d820 RCX:
> 00007fbff90a7317
> [  +0.000003] RDX: 00007fbe301fe690 RSI: 00000000c0184b18 RDI:
> 0000000000000004
> [  +0.000003] RBP: 00007fbe301fe690 R08: 0000000000000000 R09:
> 00007fbcc402d880
> [  +0.000003] R10: 0000000002001000 R11: 0000000000000246 R12:
> 00000000c0184b18
> [  +0.000003] R13: 0000000000000004 R14: 00007fbf689593a0 R15:
> 00007fbcc402d820
>
> Cc: Christian König <christian.koenig at amd.com>
> Cc: Felix Kuehling <Felix.Kuehling at amd.com>
> Cc: Alex Deucher <Alexander.Deucher at amd.com>
>
> Fixes: 627b92ef9d7c ("drm/amdgpu: Wipe all VRAM on free when RAS is
> enabled")
> Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>

The fixes tag is not necessarily correct, I would remove that.

But apart from that the patch is Reviewed-by: Christian König 
<christian.koenig at amd.com>.

Thanks,
Christian.

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> index 36bb41b027ec..6ccd2be685f5 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> @@ -1306,7 +1306,8 @@ void amdgpu_bo_release_notify(struct ttm_buffer_object *bo)
>   	    !(abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE))
>   		return;
>   
> -	dma_resv_lock(bo->base.resv, NULL);
> +	if (WARN_ON_ONCE(!dma_resv_trylock(bo->base.resv)))
> +		return;
>   
>   	r = amdgpu_fill_buffer(abo, AMDGPU_POISON, bo->base.resv, &fence);
>   	if (!WARN_ON(r)) {