[PATCH 3/4] drm/amdgpu: Avoid HW reset if guilty job already signaled.
Grodzovsky, Andrey
Andrey.Grodzovsky at amd.com
Fri Apr 12 15:53:54 UTC 2019
On 4/12/19 3:39 AM, Christian König wrote:
> 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?
That the usual way of knowing you have XGMI topology, but having
hive!=NULL should be equivalent so I can remove it.
>
>> +
>> /*
>> - * 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.
I agree this would be good in case of amdgpu_device_pre_asic_reset
because we can totally skip this function if guilty job already
signaled, but for amdgpu_device_post_asic_reset it crates complications
because drm_sched_start is right in the middle there after
drm_sched_resubmit_jobs but before forcing back set mode in display so I
prefer to keep passing 'job_signaled' to amdgpu_device_post_asic_reset.
Alternative is to get rid of this function and bring it's body into
amdgpu_device_gpu_recover which is already pretty cluttered and
confusing. What do you think ?
Andrey
>
>> +
>> +
>> + /* 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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