On 11/8/19 5:54 AM, Deng, Emily wrote:
> Hi Christian,
> Sorry, seems I understand wrong. And from the print, the free job's thread is the same as job timeout thread. So seems have some issue in function amdgpu_device_gpu_recover.
I don't think it's correct, seems your prints just don't print the pids
because it's all zeros which cannot be true for any kernel or user mode
thread. In fact looking at the OOPs i see the actual TDR job pid which is 55
CPU: 3 PID: 55 Comm: kworker/3:1 Tainted
Andrey
>
>
> Best wishes
> Emily Deng
>
>
>
>> -----Original Message-----
>> From: Koenig, Christian <Christian.Koenig@xxxxxxx>
>> Sent: Friday, November 8, 2019 6:35 PM
>> To: Deng, Emily <Emily.Deng@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
>> Subject: Re: [PATCH] drm/amdgpu: Fix the null pointer issue for tdr
>>
>> Hi Emily,
>>
>> exactly that can't happen. See here:
>>
>>> /* Don't destroy jobs while the timeout worker is running */
>>> if (sched->timeout != MAX_SCHEDULE_TIMEOUT &&
>>> !cancel_delayed_work(&sched->work_tdr))
>>> return NULL;
>> We never free jobs while the timeout working is running to prevent exactly
>> that issue.
>>
>> Regards,
>> Christian.
>>
>> Am 08.11.19 um 11:32 schrieb Deng, Emily:
>>> Hi Christian,
>>> The drm_sched_job_timedout-> amdgpu_job_timedout call
>> amdgpu_device_gpu_recover. I mean the main scheduler free the jobs while
>> in amdgpu_device_gpu_recover, and before calling drm_sched_stop.
>>> Best wishes
>>> Emily Deng
>>>
>>>
>>>
>>>> -----Original Message-----
>>>> From: Koenig, Christian <Christian.Koenig@xxxxxxx>
>>>> Sent: Friday, November 8, 2019 6:26 PM
>>>> To: Deng, Emily <Emily.Deng@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
>>>> Subject: Re: [PATCH] drm/amdgpu: Fix the null pointer issue for tdr
>>>>
>>>> Hi Emily,
>>>>
>>>> well who is calling amdgpu_device_gpu_recover() in this case?
>>>>
>>>> When it's not the scheduler we shouldn't have a guilty job in the first place.
>>>>
>>>> Regards,
>>>> Christian.
>>>>
>>>> Am 08.11.19 um 11:22 schrieb Deng, Emily:
>>>>> Hi Chrisitan,
>>>>> No, I am with the new branch and also has the patch. Even it
>>>>> are freed by
>>>> main scheduler, how we could avoid main scheduler to free jobs while
>>>> enter to function amdgpu_device_gpu_recover?
>>>>> Best wishes
>>>>> Emily Deng
>>>>>
>>>>>
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Koenig, Christian <Christian.Koenig@xxxxxxx>
>>>>>> Sent: Friday, November 8, 2019 6:15 PM
>>>>>> To: Deng, Emily <Emily.Deng@xxxxxxx>; amd-
>> gfx@xxxxxxxxxxxxxxxxxxxxx
>>>>>> Subject: Re: [PATCH] drm/amdgpu: Fix the null pointer issue for tdr
>>>>>>
>>>>>> Hi Emily,
>>>>>>
>>>>>> in this case you are on an old code branch.
>>>>>>
>>>>>> Jobs are freed now by the main scheduler thread and only if no
>>>>>> timeout handler is running.
>>>>>>
>>>>>> See this patch here:
>>>>>>> commit 5918045c4ed492fb5813f980dcf89a90fefd0a4e
>>>>>>> Author: Christian König <christian.koenig@xxxxxxx>
>>>>>>> Date: Thu Apr 18 11:00:21 2019 -0400
>>>>>>>
>>>>>>> drm/scheduler: rework job destruction
>>>>>> Regards,
>>>>>> Christian.
>>>>>>
>>>>>> Am 08.11.19 um 11:11 schrieb Deng, Emily:
>>>>>>> Hi Christian,
>>>>>>> Please refer to follow log, when it enter to
>>>>>>> amdgpu_device_gpu_recover
>>>>>> function, the bad job 000000005086879e is freeing in function
>>>>>> amdgpu_job_free_cb at the same time, because of the hardware fence
>>>> signal.
>>>>>> But amdgpu_device_gpu_recover goes faster, at this case, the
>>>>>> s_fence is already freed, but job is not freed in time. Then this issue
>> occurs.
>>>>>>> [ 449.792189] [drm:amdgpu_job_timedout [amdgpu]] *ERROR* ring
>>>> sdma0
>>>>>>> timeout, signaled seq=2481, emitted seq=2483 [ 449.793202]
>>>>>>> [drm:amdgpu_job_timedout [amdgpu]] *ERROR* Process information:
>>>>>> process pid 0 thread pid 0, s_job:000000005086879e [ 449.794163]
>>>>>> amdgpu
>>>>>> 0000:00:08.0: GPU reset begin!
>>>>>>> [ 449.794175] Emily:amdgpu_job_free_cb,Process information:
>>>>>>> process pid 0 thread pid 0, s_job:000000005086879e [ 449.794221]
>>>>>>> Emily:amdgpu_job_free_cb,Process information: process pid 0
>>>>>>> thread pid 0, s_job:0000000066eb74ab [ 449.794222]
>>>>>>> Emily:amdgpu_job_free_cb,Process information: process pid 0
>>>>>>> thread pid 0, s_job:00000000d4438ad9 [ 449.794255]
>>>>>>> Emily:amdgpu_job_free_cb,Process information: process pid 0
>>>>>>> thread pid 0, s_job:00000000b6d69c65 [ 449.794257]
>>>>>>> Emily:amdgpu_job_free_cb,Process information: process pid 0
>>>>>>> thread pid 0,
>>>>>> s_job:00000000ea85e922 [ 449.794287]
>>>>>> Emily:amdgpu_job_free_cb,Process
>>>>>> information: process pid 0 thread pid 0, s_job:00000000ed3a5ac6 [
>>>>>> 449.794366] BUG: unable to handle kernel NULL pointer dereference
>>>>>> at
>>>>>> 00000000000000c0 [ 449.800818] PGD 0 P4D 0 [ 449.801040] Oops:
>>>>>> 0000 [#1] SMP PTI
>>>>>>> [ 449.801338] CPU: 3 PID: 55 Comm: kworker/3:1 Tainted: G OE
>>>>>> 4.18.0-15-generic #16~18.04.1-Ubuntu
>>>>>>> [ 449.802157] Hardware name: QEMU Standard PC (i440FX + PIIX,
>>>>>>> 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 449.802944]
>>>>>>> Workqueue: events drm_sched_job_timedout [amd_sched] [
>>>>>>> 449.803488]
>>>> RIP:
>>>>>> 0010:amdgpu_device_gpu_recover+0x1da/0xb60 [amdgpu]
>>>>>>> [ 449.804020] Code: dd ff ff 49 39 c5 48 89 55 a8 0f 85 56 ff ff
>>>>>>> ff
>>>>>>> 45 85 e4 0f
>>>>>> 85 a1 00 00 00 48 8b 45 b0 48 85 c0 0f 84 60 01 00 00 48 8b 40 10
>>>>>> <48> 8b
>>>> 98
>>>>>> c0 00 00 00 48 85 db 0f 84 4c 01 00 00 48 8b 43 48 a8 01
>>>>>>> [ 449.805593] RSP: 0018:ffffb4c7c08f7d68 EFLAGS: 00010286 [
>>>>>>> 449.806032] RAX: 0000000000000000 RBX: 0000000000000000 RCX:
>>>>>>> 0000000000000000 [ 449.806625] RDX: ffffb4c7c08f5ac0 RSI:
>>>>>>> 0000000fffffffe0 RDI: 0000000000000246 [ 449.807224] RBP:
>>>>>>> ffffb4c7c08f7de0 R08: 00000068b9d54000 R09: 0000000000000000 [
>>>>>>> 449.807818] R10: 0000000000000000 R11: 0000000000000148 R12:
>>>>>>> 0000000000000000 [ 449.808411] R13: ffffb4c7c08f7da0 R14:
>>>>>>> ffff8d82b8525d40 R15: ffff8d82b8525d40 [ 449.809004] FS:
>>>>>>> 0000000000000000(0000) GS:ffff8d82bfd80000(0000)
>>>>>>> knlGS:0000000000000000 [ 449.809674] CS: 0010 DS: 0000 ES: 0000
>> CR0:
>>>>>>> 0000000080050033 [ 449.810153] CR2: 00000000000000c0 CR3:
>>>>>>> 000000003cc0a001 CR4: 00000000003606e0 [ 449.810747] DR0:
>>>>>> 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [
>>>>>> 449.811344] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
>>>>>> 0000000000000400 [ 449.811937] Call Trace:
>>>>>>> [ 449.812206] amdgpu_job_timedout+0x114/0x140 [amdgpu] [
>>>>>>> 449.812635] drm_sched_job_timedout+0x44/0x90 [amd_sched] [
>>>>>>> 449.813139] ? amdgpu_cgs_destroy_device+0x10/0x10 [amdgpu] [
>>>>>>> 449.813609] ? drm_sched_job_timedout+0x44/0x90 [amd_sched] [
>>>>>>> 449.814077] process_one_work+0x1fd/0x3f0 [ 449.814417]
>>>>>>> worker_thread+0x34/0x410 [ 449.814728] kthread+0x121/0x140 [
>>>>>>> 449.815004] ? process_one_work+0x3f0/0x3f0 [ 449.815374] ?
>>>>>>> kthread_create_worker_on_cpu+0x70/0x70
>>>>>>> [ 449.815799] ret_from_fork+0x35/0x40
>>>>>>>
>>>>>>>> -----Original Message-----
>>>>>>>> From: Koenig, Christian <Christian.Koenig@xxxxxxx>
>>>>>>>> Sent: Friday, November 8, 2019 5:43 PM
>>>>>>>> To: Deng, Emily <Emily.Deng@xxxxxxx>; amd-
>>>> gfx@xxxxxxxxxxxxxxxxxxxxx
>>>>>>>> Subject: Re: [PATCH] drm/amdgpu: Fix the null pointer issue for
>>>>>>>> tdr
>>>>>>>>
>>>>>>>> Am 08.11.19 um 10:39 schrieb Deng, Emily:
>>>>>>>>> Sorry, please take your time.
>>>>>>>> Have you seen my other response a bit below?
>>>>>>>>
>>>>>>>> I can't follow how it would be possible for job->s_fence to be
>>>>>>>> NULL without the job also being freed.
>>>>>>>>
>>>>>>>> So it looks like this patch is just papering over some bigger issues.
>>>>>>>>
>>>>>>>> Regards,
>>>>>>>> Christian.
>>>>>>>>
>>>>>>>>> Best wishes
>>>>>>>>> Emily Deng
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> -----Original Message-----
>>>>>>>>>> From: Koenig, Christian <Christian.Koenig@xxxxxxx>
>>>>>>>>>> Sent: Friday, November 8, 2019 5:08 PM
>>>>>>>>>> To: Deng, Emily <Emily.Deng@xxxxxxx>; amd-
>>>>>> gfx@xxxxxxxxxxxxxxxxxxxxx
>>>>>>>>>> Subject: Re: [PATCH] drm/amdgpu: Fix the null pointer issue for
>>>>>>>>>> tdr
>>>>>>>>>>
>>>>>>>>>> Am 08.11.19 um 09:52 schrieb Deng, Emily:
>>>>>>>>>>> Ping.....
>>>>>>>>>> You need to give me at least enough time to wake up :)
>>>>>>>>>>
>>>>>>>>>>> Best wishes
>>>>>>>>>>> Emily Deng
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>> -----Original Message-----
>>>>>>>>>>>> From: amd-gfx <amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On
>>>> Behalf
>>>>>>>>>>>> Of Deng, Emily
>>>>>>>>>>>> Sent: Friday, November 8, 2019 10:56 AM
>>>>>>>>>>>> To: Koenig, Christian <Christian.Koenig@xxxxxxx>; amd-
>>>>>>>>>>>> gfx@xxxxxxxxxxxxxxxxxxxxx
>>>>>>>>>>>> Subject: RE: [PATCH] drm/amdgpu: Fix the null pointer issue
>>>>>>>>>>>> for tdr
>>>>>>>>>>>>
>>>>>>>>>>>>> -----Original Message-----
>>>>>>>>>>>>> From: Christian König <ckoenig.leichtzumerken@xxxxxxxxx>
>>>>>>>>>>>>> Sent: Thursday, November 7, 2019 7:28 PM
>>>>>>>>>>>>> To: Deng, Emily <Emily.Deng@xxxxxxx>;
>>>>>>>>>>>>> amd-gfx@xxxxxxxxxxxxxxxxxxxxx
>>>>>>>>>>>>> Subject: Re: [PATCH] drm/amdgpu: Fix the null pointer issue
>>>>>>>>>>>>> for tdr
>>>>>>>>>>>>>
>>>>>>>>>>>>> Am 07.11.19 um 11:25 schrieb Emily Deng:
>>>>>>>>>>>>>> When the job is already signaled, the s_fence is freed.
>>>>>>>>>>>>>> Then it will has null pointer in amdgpu_device_gpu_recover.
>>>>>>>>>>>>> NAK, the s_fence is only set to NULL when the job is destroyed.
>>>>>>>>>>>>> See drm_sched_job_cleanup().
>>>>>>>>>>>> I know it is set to NULL in drm_sched_job_cleanup. But in one
>>>>>>>>>>>> case, when it enter into the amdgpu_device_gpu_recover, it
>>>>>>>>>>>> already in drm_sched_job_cleanup, and at this time, it will
>>>>>>>>>>>> go to free
>>>>>> job.
>>>>>>>>>>>> But the amdgpu_device_gpu_recover sometimes is faster. At
>>>>>>>>>>>> that time, job is not freed, but s_fence is already NULL.
>>>>>>>>>> No, that case can't happen. See here:
>>>>>>>>>>
>>>>>>>>>>> drm_sched_job_cleanup(s_job);
>>>>>>>>>>>
>>>>>>>>>>> amdgpu_ring_priority_put(ring, s_job->s_priority);
>>>>>>>>>>> dma_fence_put(job->fence);
>>>>>>>>>>> amdgpu_sync_free(&job->sync);
>>>>>>>>>>> amdgpu_sync_free(&job->sched_sync);
>>>>>>>>>>> kfree(job);
>>>>>>>>>> The job itself is freed up directly after freeing the reference
>>>>>>>>>> to the
>>>>>> s_fence.
>>>>>>>>>> So you are just papering over a much bigger problem here. This
>>>>>>>>>> patch is a clear NAK.
>>>>>>>>>>
>>>>>>>>>> Regards,
>>>>>>>>>> Christian.
>>>>>>>>>>
>>>>>>>>>>>>> When you see a job without an s_fence then that means the
>>>>>>>>>>>>> problem is somewhere else.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Regards,
>>>>>>>>>>>>> Christian.
>>>>>>>>>>>>>
>>>>>>>>>>>>>> Signed-off-by: Emily Deng <Emily.Deng@xxxxxxx>
>>>>>>>>>>>>>> ---
>>>>>>>>>>>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +-
>>>>>>>>>>>>>> drivers/gpu/drm/scheduler/sched_main.c | 11 ++++++---
>> --
>>>>>>>>>>>>>> 2 files changed, 7 insertions(+), 6 deletions(-)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>>>>>>>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>>>>>>>>>>> index e6ce949..5a8f08e 100644
>>>>>>>>>>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>>>>>>>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>>>>>>>>>>> @@ -4075,7 +4075,7 @@ int
>>>> amdgpu_device_gpu_recover(struct
>>>>>>>>>>>>> amdgpu_device *adev,
>>>>>>>>>>>>>> *
>>>>>>>>>>>>>> * job->base holds a reference to parent fence
>>>>>>>>>>>>>> */
>>>>>>>>>>>>>> - if (job && job->base.s_fence->parent &&
>>>>>>>>>>>>>> + if (job && job->base.s_fence && job->base.s_fence-
>>> parent
>>>>>>>> &&
>>>>>>>>>>>>>> dma_fence_is_signaled(job->base.s_fence->parent))
>>>>>>>>>>>>>> job_signaled = true;
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> diff --git a/drivers/gpu/drm/scheduler/sched_main.c
>>>>>>>>>>>>>> b/drivers/gpu/drm/scheduler/sched_main.c
>>>>>>>>>>>>>> index 31809ca..56cc10e 100644
>>>>>>>>>>>>>> --- a/drivers/gpu/drm/scheduler/sched_main.c
>>>>>>>>>>>>>> +++ b/drivers/gpu/drm/scheduler/sched_main.c
>>>>>>>>>>>>>> @@ -334,8 +334,8 @@ void
>> drm_sched_increase_karma(struct
>>>>>>>>>>>>> drm_sched_job
>>>>>>>>>>>>>> *bad)
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> spin_lock(&rq->lock);
>>>>>>>>>>>>>> list_for_each_entry_safe(entity, tmp,
>>>> &rq-
>>>>>>>>> entities,
>>>>>>>>>>>>> list) {
>>>>>>>>>>>>>> - if (bad->s_fence-
>>> scheduled.context
>>>>>>>> ==
>>>>>>>>>>>>>> - entity->fence_context) {
>>>>>>>>>>>>>> + if (bad->s_fence && (bad-
>>> s_fence-
>>>>>>>>>>>>>> scheduled.context ==
>>>>>>>>>>>>>> + entity->fence_context)) {
>>>>>>>>>>>>>> if (atomic_read(&bad-
>>>>>>>>> karma) >
>>>>>>>>>>>>>> bad->sched-
>>>>> hang_limit)
>>>>>>>>>>>>>> if (entity-
>>>>> guilty) @@ -376,7 +376,7 @@ void
>>>>>>>>>>>>>> drm_sched_stop(struct
>>>>>>>> drm_gpu_scheduler
>>>>>>>>>>>>> *sched, struct drm_sched_job *bad)
>>>>>>>>>>>>>> * This iteration is thread safe as sched thread is
>>>> stopped.
>>>>>>>>>>>>>> */
>>>>>>>>>>>>>> list_for_each_entry_safe_reverse(s_job, tmp,
>>>>>>>>>>>>>> &sched- ring_mirror_list, node) {
>>>>>>>>>>>>>> - if (s_job->s_fence->parent &&
>>>>>>>>>>>>>> + if (s_job->s_fence && s_job->s_fence->parent
>> &&
>>>>>>>>>>>>>> dma_fence_remove_callback(s_job-
>>>>> s_fence-
>>>>>>>>> parent,
>>>>>>>>>>>>>> &s_job->cb)) {
>>>>>>>>>>>>>> atomic_dec(&sched->hw_rq_count);
>>>> @@ -
>>>>>>>> 395,7
>>>>>>>>>>>> +395,8 @@ void
>>>>>>>>>>>>>> drm_sched_stop(struct drm_gpu_scheduler
>>>>>>>>>>>>> *sched, struct drm_sched_job *bad)
>>>>>>>>>>>>>> *
>>>>>>>>>>>>>> * Job is still alive so fence refcount at
>>>> least 1
>>>>>>>>>>>>>> */
>>>>>>>>>>>>>> - dma_fence_wait(&s_job->s_fence-
>>> finished,
>>>>>>>> false);
>>>>>>>>>>>>>> + if (s_job->s_fence)
>>>>>>>>>>>>>> + dma_fence_wait(&s_job-
>>> s_fence-
>>>>>>>>> finished,
>>>>>>>>>>>>> false);
>>>>>>>>>>>>>> /*
>>>>>>>>>>>>>> * We must keep bad job alive for later
>>>> use
>>>>>>>> during @@
>>>>>>>>>>>>> -438,7
>>>>>>>>>>>>>> +439,7 @@ void drm_sched_start(struct drm_gpu_scheduler
>>>>>> *sched,
>>>>>>>>>>>>>> +bool
>>>>>>>>>>>>> full_recovery)
>>>>>>>>>>>>>> * GPU recovers can't run in parallel.
>>>>>>>>>>>>>> */
>>>>>>>>>>>>>> list_for_each_entry_safe(s_job, tmp,
>>>>>>>>>>>>>> &sched->ring_mirror_list,
>>>>>>>>>>>>>> node)
>>>>>>>>>>>>> {
>>>>>>>>>>>>>> - struct dma_fence *fence = s_job->s_fence-
>>> parent;
>>>>>>>>>>>>>> + struct dma_fence *fence = s_job->s_fence ?
>> s_job-
>>>>>>>>> s_fence-
>>>>>>>>>>>>>> parent :
>>>>>>>>>>>>>> +NULL;
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> atomic_inc(&sched->hw_rq_count);
>>>>>>>>>>>>>>
>>>>>>>>>>>> _______________________________________________
>>>>>>>>>>>> amd-gfx mailing list
>>>>>>>>>>>> amd-gfx@xxxxxxxxxxxxxxxxxxxxx
>>>>>>>>>>>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
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