[PATCH 3/4] drm/amdgpu: Avoid HW reset if guilty job already signaled.

Christian König ckoenig.leichtzumerken at gmail.com
Fri Apr 12 07:39:03 UTC 2019


Am 11.04.19 um 18:03 schrieb Andrey Grodzovsky:
> Also reject TDRs if another one already running.
>
> v2:
> Stop all schedulers across device and entire XGMI hive before
> force signaling HW fences.
>
> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 125 ++++++++++++++++++++---------
>   1 file changed, 88 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index aabd043..ce9c494 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -3327,7 +3327,8 @@ bool amdgpu_device_should_recover_gpu(struct amdgpu_device *adev)
>   
>   static int amdgpu_device_pre_asic_reset(struct amdgpu_device *adev,
>   					struct amdgpu_job *job,
> -					bool *need_full_reset_arg)
> +					bool *need_full_reset_arg,
> +					bool job_signaled)
>   {
>   	int i, r = 0;
>   	bool need_full_reset  = *need_full_reset_arg;
> @@ -3339,8 +3340,6 @@ static int amdgpu_device_pre_asic_reset(struct amdgpu_device *adev,
>   		if (!ring || !ring->sched.thread)
>   			continue;
>   
> -		drm_sched_stop(&ring->sched, &job->base);
> -
>   		/* after all hw jobs are reset, hw fence is meaningless, so force_completion */
>   		amdgpu_fence_driver_force_completion(ring);
>   	}
> @@ -3358,7 +3357,8 @@ static int amdgpu_device_pre_asic_reset(struct amdgpu_device *adev,
>   
>   
>   
> -	if (!amdgpu_sriov_vf(adev)) {
> +	/* Don't suspend on bare metal if we are not going to HW reset the ASIC */
> +	if (!amdgpu_sriov_vf(adev) && !job_signaled) {
>   
>   		if (!need_full_reset)
>   			need_full_reset = amdgpu_device_ip_need_full_reset(adev);
> @@ -3495,7 +3495,7 @@ static int amdgpu_do_asic_reset(struct amdgpu_hive_info *hive,
>   	return r;
>   }
>   
> -static void amdgpu_device_post_asic_reset(struct amdgpu_device *adev)
> +static void amdgpu_device_post_asic_reset(struct amdgpu_device *adev, bool job_signaled)
>   {
>   	int i;
>   
> @@ -3505,7 +3505,8 @@ static void amdgpu_device_post_asic_reset(struct amdgpu_device *adev)
>   		if (!ring || !ring->sched.thread)
>   			continue;
>   
> -		if (!adev->asic_reset_res)
> +		/* No point to resubmit jobs if we didn't HW reset*/
> +		if (!adev->asic_reset_res && !job_signaled)
>   			drm_sched_resubmit_jobs(&ring->sched);
>   
>   		drm_sched_start(&ring->sched, !adev->asic_reset_res);
> @@ -3518,14 +3519,21 @@ static void amdgpu_device_post_asic_reset(struct amdgpu_device *adev)
>   	adev->asic_reset_res = 0;
>   }
>   
> -static void amdgpu_device_lock_adev(struct amdgpu_device *adev)
> +static bool amdgpu_device_lock_adev(struct amdgpu_device *adev, bool trylock)
>   {
> -	mutex_lock(&adev->lock_reset);
> +	if (trylock) {
> +		if (!mutex_trylock(&adev->lock_reset))
> +			return false;
> +	} else
> +		mutex_lock(&adev->lock_reset);
> +
>   	atomic_inc(&adev->gpu_reset_counter);
>   	adev->in_gpu_reset = 1;
>   	/* Block kfd: SRIOV would do it separately */
>   	if (!amdgpu_sriov_vf(adev))
>                   amdgpu_amdkfd_pre_reset(adev);
> +
> +	return true;
>   }
>   
>   static void amdgpu_device_unlock_adev(struct amdgpu_device *adev)
> @@ -3553,38 +3561,43 @@ static void amdgpu_device_unlock_adev(struct amdgpu_device *adev)
>   int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
>   			      struct amdgpu_job *job)
>   {
> -	int r;
> +	int r, i;

BTW: Usual kernel coding style is to use reverse xmas tree. E.g. 
variables like "int i, r" last in the declarations.

>   	struct amdgpu_hive_info *hive = NULL;
> -	bool need_full_reset = false;
>   	struct amdgpu_device *tmp_adev = NULL;
>   	struct list_head device_list, *device_list_handle =  NULL;
> +	bool xgmi_topology_present, need_full_reset, job_signaled;
>   
> +	need_full_reset = job_signaled = false;
>   	INIT_LIST_HEAD(&device_list);
>   
>   	dev_info(adev->dev, "GPU reset begin!\n");
>   
> +	hive = amdgpu_get_xgmi_hive(adev, 0);

The second parameter should actually be a bool, so please use false here.

> +	xgmi_topology_present = hive && adev->gmc.xgmi.num_physical_nodes > 1;

Why are we actually checking num_physical_nodes here?

> +
>   	/*
> -	 * In case of XGMI hive disallow concurrent resets to be triggered
> -	 * by different nodes. No point also since the one node already executing
> -	 * reset will also reset all the other nodes in the hive.
> +	 * Here we trylock to avoid chain of resets executing from
> +	 * either trigger by jobs on different adevs in XGMI hive or jobs on
> +	 * different schedulers for same device while this tdr is running.

Can we please completely drop the name "tdr" and just write "timeout 
handler"?

> +	 * We always reset all schedulers for device and all devices for XGMI
> +	 * hive so that should take care of them too.
>   	 */
> -	hive = amdgpu_get_xgmi_hive(adev, 0);
> -	if (hive && adev->gmc.xgmi.num_physical_nodes > 1 &&
> -	    !mutex_trylock(&hive->reset_lock))
> +
> +	if (xgmi_topology_present && !mutex_trylock(&hive->reset_lock)) {
> +		DRM_INFO("Bailing on TDR for s_job:%llx, hive: %llx as another already in progress",
> +			 job->base.id, hive->hive_id);
>   		return 0;
> +	}
>   
>   	/* Start with adev pre asic reset first for soft reset check.*/
> -	amdgpu_device_lock_adev(adev);
> -	r = amdgpu_device_pre_asic_reset(adev,
> -					 job,
> -					 &need_full_reset);
> -	if (r) {
> -		/*TODO Should we stop ?*/
> -		DRM_ERROR("GPU pre asic reset failed with err, %d for drm dev, %s ",
> -			  r, adev->ddev->unique);
> -		adev->asic_reset_res = r;
> +	if (!amdgpu_device_lock_adev(adev, !xgmi_topology_present)) {
> +		DRM_INFO("Bailing on TDR for s_job:%llx, as another already in progress",
> +					 job->base.id);
> +		return 0;
>   	}
>   
> +	need_full_reset = amdgpu_device_ip_need_full_reset(adev);
> +
>   	/* Build list of devices to reset */
>   	if  (need_full_reset && adev->gmc.xgmi.num_physical_nodes > 1) {

We should probably unconditionally stop all nodes on all device first 
and then try to figure out if we actually need a full reset.

>   		if (!hive) {
> @@ -3603,16 +3616,52 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
>   		device_list_handle = &device_list;
>   	}
>   
> +	/* block all schedulers and reset given job's ring */
> +	list_for_each_entry(tmp_adev, device_list_handle, gmc.xgmi.head) {
> +		for (i = 0; i < AMDGPU_MAX_RINGSBuild list of devices to reset
> ; ++i) {
> +			struct amdgpu_ring *ring = tmp_adev->rings[i];
> +
> +			if (!ring || !ring->sched.thread)
> +				continue;
> +
> +			drm_sched_stop(&ring->sched, &job->base);
> +		}
> +	}
> +
> +	/*
> +	 * Must check guilty signal here since after this point all old
> +	 * HW fences are force signaled.
> +	 *
> +	 * job->base holds a reference to parent fence
> +	 */
> +	if (job && job->base.s_fence->parent &&
> +	    dma_fence_is_signaled(job->base.s_fence->parent))
> +		job_signaled = true;

It would probably be better if we have a "goto abort;" or something 
similar here.

This also avoids giving the job_signaled variable to all the sub functions.

Christian.

> +
> +
> +	/* Guilty job will be freed after this*/
> +	r = amdgpu_device_pre_asic_reset(adev,
> +					 job,
> +					 &need_full_reset,
> +					 job_signaled);
> +	if (r) {
> +		/*TODO Should we stop ?*/
> +		DRM_ERROR("GPU pre asic reset failed with err, %d for drm dev, %s ",
> +			  r, adev->ddev->unique);
> +		adev->asic_reset_res = r;
> +	}
> +
>   retry:	/* Rest of adevs pre asic reset from XGMI hive. */
>   	list_for_each_entry(tmp_adev, device_list_handle, gmc.xgmi.head) {
>   
>   		if (tmp_adev == adev)
>   			continue;
>   
> -		amdgpu_device_lock_adev(tmp_adev);
> +		amdgpu_device_lock_adev(tmp_adev, false);
>   		r = amdgpu_device_pre_asic_reset(tmp_adev,
>   						 NULL,
> -						 &need_full_reset);
> +						 &need_full_reset,
> +						 job_signaled);
>   		/*TODO Should we stop ?*/
>   		if (r) {
>   			DRM_ERROR("GPU pre asic reset failed with err, %d for drm dev, %s ",
> @@ -3623,19 +3672,21 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
>   
>   	/* Actual ASIC resets if needed.*/
>   	/* TODO Implement XGMI hive reset logic for SRIOV */
> -	if (amdgpu_sriov_vf(adev)) {
> -		r = amdgpu_device_reset_sriov(adev, job ? false : true);
> -		if (r)
> -			adev->asic_reset_res = r;
> -	} else {
> -		r  = amdgpu_do_asic_reset(hive, device_list_handle, &need_full_reset);
> -		if (r && r == -EAGAIN)
> -			goto retry;
> +	if (!job || !job_signaled) {
> +		if (amdgpu_sriov_vf(adev)) {
> +			r = amdgpu_device_reset_sriov(adev, job ? false : true);
> +			if (r)
> +				adev->asic_reset_res = r;
> +		} else {
> +			r  = amdgpu_do_asic_reset(hive, device_list_handle, &need_full_reset);
> +			if (r && r == -EAGAIN)
> +				goto retry;
> +		}
>   	}
>   
>   	/* Post ASIC reset for all devs .*/
>   	list_for_each_entry(tmp_adev, device_list_handle, gmc.xgmi.head) {
> -		amdgpu_device_post_asic_reset(tmp_adev);
> +		amdgpu_device_post_asic_reset(tmp_adev, job_signaled);
>   
>   		if (r) {
>   			/* bad news, how to tell it to userspace ? */
> @@ -3648,7 +3699,7 @@ int amdgpu_device_gpu_recover(struct amdgpu_device *adev,
>   		amdgpu_device_unlock_adev(tmp_adev);
>   	}
>   
> -	if (hive && adev->gmc.xgmi.num_physical_nodes > 1)
> +	if (xgmi_topology_present)
>   		mutex_unlock(&hive->reset_lock);
>   
>   	if (r)



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