[Patch v2 3/4] drm/amdkfd: refactor runtime pm for baco

Bhardwaj, Rajneesh rajneesh.bhardwaj at amd.com
Wed Feb 5 00:57:15 UTC 2020


Hi Felix,

Thanks for the review feedback!

On 2/4/2020 4:28 PM, Felix Kuehling wrote:
> On 2020-01-31 10:37 p.m., Rajneesh Bhardwaj wrote:
>> So far the kfd driver implemented same routines for runtime and system
>> wide suspend and resume (s2idle or mem). During system wide suspend the
>> kfd aquires an atomic lock that prevents any more user processes to
>> create queues and interact with kfd driver and amd gpu. This mechanism
>> created problem when amdgpu device is runtime suspended with BACO
>> enabled. Any application that relies on kfd driver fails to load because
>> the driver reports a locked kfd device since gpu is runtime suspended.
>>
>> However, in an ideal case, when gpu is runtime  suspended the kfd driver
>> should be able to:
>>
>>   - auto resume amdgpu driver whenever a client requests compute service
>>   - prevent runtime suspend for amdgpu  while kfd is in use
>>
>> This change refactors the amdgpu and amdkfd drivers to support BACO and
>> runtime power management.
>>
>> Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>
>
> One small comment inline. Other than that patches 1-3 are
>
> Reviewed-by: Felix Kuehling <Felix.Kuehling at amd.com>
>
> Also, I believe patch 1 is unchanged from v1 and already got a 
> Reviewed-by from Alex. Please remember to add that tag before you submit.


You mean https://www.spinics.net/lists/amd-gfx/msg44689.html? I have 
already added Alex's RB tag.


>
>
> The last patch that enabled runtime PM by default, I'd leave the 
> decision to submit that up to Alex. There may be other considerations 
> than just KFD.


Sure, but its needed along with the series otherwise we can't test/use it.


>
>
> See inline ...
>
>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c | 12 +++---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h |  8 ++--
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  4 +-
>>   drivers/gpu/drm/amd/amdkfd/kfd_device.c    | 29 +++++++++------
>>   drivers/gpu/drm/amd/amdkfd/kfd_priv.h      |  1 +
>>   drivers/gpu/drm/amd/amdkfd/kfd_process.c   | 43 ++++++++++++++++++++--
>>   6 files changed, 70 insertions(+), 27 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
>> index 8609287620ea..314c4a2a0354 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
>> @@ -178,18 +178,18 @@ void amdgpu_amdkfd_interrupt(struct 
>> amdgpu_device *adev,
>>           kgd2kfd_interrupt(adev->kfd.dev, ih_ring_entry);
>>   }
>>   -void amdgpu_amdkfd_suspend(struct amdgpu_device *adev)
>> +void amdgpu_amdkfd_suspend(struct amdgpu_device *adev, bool run_pm)
>>   {
>>       if (adev->kfd.dev)
>> -        kgd2kfd_suspend(adev->kfd.dev);
>> +        kgd2kfd_suspend(adev->kfd.dev, run_pm);
>>   }
>>   -int amdgpu_amdkfd_resume(struct amdgpu_device *adev)
>> +int amdgpu_amdkfd_resume(struct amdgpu_device *adev, bool run_pm)
>>   {
>>       int r = 0;
>>         if (adev->kfd.dev)
>> -        r = kgd2kfd_resume(adev->kfd.dev);
>> +        r = kgd2kfd_resume(adev->kfd.dev, run_pm);
>>         return r;
>>   }
>> @@ -713,11 +713,11 @@ void kgd2kfd_exit(void)
>>   {
>>   }
>>   -void kgd2kfd_suspend(struct kfd_dev *kfd)
>> +void kgd2kfd_suspend(struct kfd_dev *kfd, bool run_pm)
>>   {
>>   }
>>   -int kgd2kfd_resume(struct kfd_dev *kfd)
>> +int kgd2kfd_resume(struct kfd_dev *kfd, bool run_pm)
>>   {
>>       return 0;
>>   }
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
>> index 47b0f2957d1f..9e8db702d878 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
>> @@ -122,8 +122,8 @@ struct amdkfd_process_info {
>>   int amdgpu_amdkfd_init(void);
>>   void amdgpu_amdkfd_fini(void);
>>   -void amdgpu_amdkfd_suspend(struct amdgpu_device *adev);
>> -int amdgpu_amdkfd_resume(struct amdgpu_device *adev);
>> +void amdgpu_amdkfd_suspend(struct amdgpu_device *adev, bool run_pm);
>> +int amdgpu_amdkfd_resume(struct amdgpu_device *adev, bool run_pm);
>>   void amdgpu_amdkfd_interrupt(struct amdgpu_device *adev,
>>               const void *ih_ring_entry);
>>   void amdgpu_amdkfd_device_probe(struct amdgpu_device *adev);
>> @@ -249,8 +249,8 @@ bool kgd2kfd_device_init(struct kfd_dev *kfd,
>>                struct drm_device *ddev,
>>                const struct kgd2kfd_shared_resources *gpu_resources);
>>   void kgd2kfd_device_exit(struct kfd_dev *kfd);
>> -void kgd2kfd_suspend(struct kfd_dev *kfd);
>> -int kgd2kfd_resume(struct kfd_dev *kfd);
>> +void kgd2kfd_suspend(struct kfd_dev *kfd, bool run_pm);
>> +int kgd2kfd_resume(struct kfd_dev *kfd, bool run_pm);
>>   int kgd2kfd_pre_reset(struct kfd_dev *kfd);
>>   int kgd2kfd_post_reset(struct kfd_dev *kfd);
>>   void kgd2kfd_interrupt(struct kfd_dev *kfd, const void 
>> *ih_ring_entry);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> index 5030a09babb8..43843e6c4bcd 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> @@ -3311,7 +3311,7 @@ int amdgpu_device_suspend(struct drm_device 
>> *dev, bool fbcon)
>>           }
>>       }
>>   -    amdgpu_amdkfd_suspend(adev);
>> +    amdgpu_amdkfd_suspend(adev, !fbcon);
>>         amdgpu_ras_suspend(adev);
>>   @@ -3395,7 +3395,7 @@ int amdgpu_device_resume(struct drm_device 
>> *dev, bool fbcon)
>>               }
>>           }
>>       }
>> -    r = amdgpu_amdkfd_resume(adev);
>> +    r = amdgpu_amdkfd_resume(adev, !fbcon);
>>       if (r)
>>           return r;
>>   diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device.c 
>> b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
>> index 798ad1c8f799..42ee9ea5c45a 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_device.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
>> @@ -732,7 +732,7 @@ bool kgd2kfd_device_init(struct kfd_dev *kfd,
>>   void kgd2kfd_device_exit(struct kfd_dev *kfd)
>>   {
>>       if (kfd->init_complete) {
>> -        kgd2kfd_suspend(kfd);
>> +        kgd2kfd_suspend(kfd, false);
>>           device_queue_manager_uninit(kfd->dqm);
>>           kfd_interrupt_exit(kfd);
>>           kfd_topology_remove_device(kfd);
>> @@ -753,7 +753,7 @@ int kgd2kfd_pre_reset(struct kfd_dev *kfd)
>>         kfd->dqm->ops.pre_reset(kfd->dqm);
>>   -    kgd2kfd_suspend(kfd);
>> +    kgd2kfd_suspend(kfd, false);
>>         kfd_signal_reset_event(kfd);
>>       return 0;
>> @@ -787,21 +787,23 @@ bool kfd_is_locked(void)
>>       return  (atomic_read(&kfd_locked) > 0);
>>   }
>>   -void kgd2kfd_suspend(struct kfd_dev *kfd)
>> +void kgd2kfd_suspend(struct kfd_dev *kfd, bool run_pm)
>>   {
>>       if (!kfd->init_complete)
>>           return;
>>   -    /* For first KFD device suspend all the KFD processes */
>> -    if (atomic_inc_return(&kfd_locked) == 1)
>> -        kfd_suspend_all_processes();
>> +    /* for runtime suspend, skip locking kfd */
>> +    if (!run_pm) {
>> +        /* For first KFD device suspend all the KFD processes */
>> +        if (atomic_inc_return(&kfd_locked) == 1)
>> +            kfd_suspend_all_processes();
>> +    }
>>         kfd->dqm->ops.stop(kfd->dqm);
>> -
>>       kfd_iommu_suspend(kfd);
>>   }
>>   -int kgd2kfd_resume(struct kfd_dev *kfd)
>> +int kgd2kfd_resume(struct kfd_dev *kfd, bool run_pm)
>>   {
>>       int ret, count;
>>   @@ -812,10 +814,13 @@ int kgd2kfd_resume(struct kfd_dev *kfd)
>>       if (ret)
>>           return ret;
>>   -    count = atomic_dec_return(&kfd_locked);
>> -    WARN_ONCE(count < 0, "KFD suspend / resume ref. error");
>> -    if (count == 0)
>> -        ret = kfd_resume_all_processes();
>> +    /* for runtime resume, skip unlocking kfd */
>> +    if (!run_pm) {
>> +        count = atomic_dec_return(&kfd_locked);
>> +        WARN_ONCE(count < 0, "KFD suspend / resume ref. error");
>> +        if (count == 0)
>> +            ret = kfd_resume_all_processes();
>> +    }
>>         return ret;
>>   }
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h 
>> b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
>> index c0b0defc8f7a..20dd4747250d 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
>> @@ -647,6 +647,7 @@ struct kfd_process_device {
>>        * function.
>>        */
>>       bool already_dequeued;
>> +    bool runtime_inuse;
>>         /* Is this process/pasid bound to this device? 
>> (amd_iommu_bind_pasid) */
>>       enum kfd_pdd_bound bound;
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c 
>> b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> index 25b90f70aecd..6907a5a2cbc8 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> @@ -31,6 +31,7 @@
>>   #include <linux/compat.h>
>>   #include <linux/mman.h>
>>   #include <linux/file.h>
>> +#include <linux/pm_runtime.h>
>>   #include "amdgpu_amdkfd.h"
>>   #include "amdgpu.h"
>>   @@ -440,6 +441,16 @@ static void kfd_process_destroy_pdds(struct 
>> kfd_process *p)
>>           kfree(pdd->qpd.doorbell_bitmap);
>>           idr_destroy(&pdd->alloc_idr);
>>   +        /*
>> +         * before destroying pdd, make sure to report availability
>> +         * for auto suspend
>> +         */
>> +        if (pdd->runtime_inuse) {
>> + pm_runtime_mark_last_busy(pdd->dev->ddev->dev);
>> + pm_runtime_put_autosuspend(pdd->dev->ddev->dev);
>> +            pdd->runtime_inuse = false;
>> +        }
>> +
>>           kfree(pdd);
>>       }
>>   }
>> @@ -754,6 +765,7 @@ struct kfd_process_device 
>> *kfd_create_process_device_data(struct kfd_dev *dev,
>>       pdd->process = p;
>>       pdd->bound = PDD_UNBOUND;
>>       pdd->already_dequeued = false;
>> +    pdd->runtime_inuse = false;
>>       list_add(&pdd->per_device_list, &p->per_device_data);
>>         /* Init idr used for memory handle translation */
>> @@ -843,15 +855,40 @@ struct kfd_process_device 
>> *kfd_bind_process_to_device(struct kfd_dev *dev,
>>           return ERR_PTR(-ENOMEM);
>>       }
>>   +    /*
>> +     * signal runtime-pm system to auto resume and prevent
>> +     * further runtime suspend once device pdd is created until
>> +     * pdd is destroyed.
>> +     */
>> +    if (!pdd->runtime_inuse) {
>> +        err = pm_runtime_get_sync(dev->ddev->dev);
>> +        if (err < 0)
>> +            return ERR_PTR(err);
>> +    }
>> +
>>       err = kfd_iommu_bind_process_to_device(pdd);
>>       if (err)
>> -        return ERR_PTR(err);
>> +        goto out;
>>         err = kfd_process_device_init_vm(pdd, NULL);
>>       if (err)
>> -        return ERR_PTR(err);
>> +        goto out;
>>   -    return pdd;
>> +    if (!err) {
>> +        /*
>> +         * make sure that runtime_usage counter is incremented
>> +         * just once per pdd
>> +         */
>> +        if (!pdd->runtime_inuse)
>> +            pdd->runtime_inuse = true;
>
> The "if" is redundant here. You can just set pdd->runtime_inuse = true 
> unconditionally.
> Regards,
>   Felix
>
Thanks

Rajneesh

>> +
>> +        return pdd;
>> +    }
>> +out:
>> +    /* balance runpm reference count and exit with error */
>> +    pm_runtime_mark_last_busy(dev->ddev->dev);
>> +    pm_runtime_put_autosuspend(dev->ddev->dev);
>> +    return ERR_PTR(err);
>>   }
>>     struct kfd_process_device *kfd_get_first_process_device_data(


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