Am 23.09.21 um 14:09 schrieb Yu, Lang:
[AMD Official Use Only]
-----Original Message-----
From: Koenig, Christian <Christian.Koenig@xxxxxxx>
Sent: Thursday, September 23, 2021 7:40 PM
To: Yu, Lang <Lang.Yu@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
Cc: Kuehling, Felix <Felix.Kuehling@xxxxxxx>; Christian K nig
<C3B6christian.koenig@xxxxxxx>; Huang, Ray <Ray.Huang@xxxxxxx>
Subject: Re: [PATCH] drm/kfd: fix ttm_bo_release warning
Am 23.09.21 um 11:44 schrieb Lang Yu:
If a BO is pinned, unpin it before freeing it.
Call Trace:
ttm_bo_put+0x30/0x50 [ttm]
amdgpu_bo_unref+0x1e/0x30 [amdgpu]
amdgpu_gem_object_free+0x34/0x50 [amdgpu]
drm_gem_object_free+0x1d/0x30 [drm]
amdgpu_amdkfd_gpuvm_free_memory_of_gpu+0x31f/0x3a0 [amdgpu]
kfd_process_device_free_bos+0xa3/0xf0 [amdgpu]
kfd_process_wq_release+0x224/0x2e0 [amdgpu]
process_one_work+0x220/0x3c0
worker_thread+0x4d/0x3f0
kthread+0x114/0x150
process_one_work+0x3c0/0x3c0
kthread_park+0x90/0x90
ret_from_fork+0x22/0x30
Signed-off-by: Lang Yu <lang.yu@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 2d6b2d77b738..7e693b064072 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -1567,6 +1567,9 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
pr_debug("Release VA 0x%llx - 0x%llx\n", mem->va,
mem->va + bo_size * (1 + mem->aql_queue));
+ if (mem->bo->tbo.pin_count)
+ amdgpu_bo_unpin(mem->bo);
+
NAK, using mem->bo->tbo.pin_count like this is illegal.
I didn't get your point. I referred to function-"void amdgpu_bo_unpin(struct amdgpu_bo *bo)",
which uses it like this.
What amdgpu_bo_unpin() does is the following:
ttm_bo_unpin(&bo->tbo);
if (bo->tbo.pin_count)
return;
....
In other words we take further actions based on if the buffer us is
still pinned or not after an unpin operation.
What you try to do here is unpinning the BO when it is pinned
independent if somebody else or our code has pinned it before.
That can lead to all kind of problems and is clearly illegal.
Where was the BO pinned in the first place?
I found two places:
ret = kfd_process_alloc_gpuvm(pdd, qpd->ib_base, PAGE_SIZE, flags,
&kaddr);
ret = kfd_process_alloc_gpuvm(pdd, qpd->cwsr_base,
KFD_CWSR_TBA_TMA_SIZE, flags, &kaddr);
Well then you need to figure out where that memory is freed again and
place the unpin appropriately.
General rule of thumb is that calls to amdgpu_bo_pin/amdgpu_bo_unpin
should be balanced.
Regards,
Christian.
Regards,
Lang
Christian.
ret = unreserve_bo_and_vms(&ctx, false, false);
/* Remove from VM internal data structures */
