[Patch v1 5/5] drm/amdkfd: refactor runtime pm for baco
Felix Kuehling
felix.kuehling at amd.com
Thu Jan 30 21:55:51 UTC 2020
On 2020-01-30 14:01, Bhardwaj, Rajneesh wrote:
> Hello Felix,
>
> Thanks for your time to review and for your feedback.
>
> On 1/29/2020 5:52 PM, Felix Kuehling wrote:
>> HI Rajneesh,
>>
>> See comments inline ...
>>
>> And a general question: Why do you need to set the autosuspend_delay
>> in so many places? Amdgpu only has a single call to this function
>> during initialization.
>
>
> We don't. I have called this out in cover letter since i too feel its
> not the best way to do what we want to do. I have seen weird issues on
> dual GPUs with KFDTest that sometimes results in system hang and gpu
> hang etc.
>
> Even if i try with running kfdtest on just one node in a multi gpu
> system, the baco exit seems to wake up all gpus and then one goes to
> auto suspend again while other performs the desired kfdtest operation.
> I have never seen any issue with a single gpu card. So in current
> approch, i am making sure that the GPUs are not quickly auto-suspended
> while the kfd operations are ongoing but once the kfdtest is finished,
> the runtime suspend call with ensure to reset the timeout back to 5
> seconds.
So by setting the timeout to 60s, you can fix applications that run for
less than 60s without calling into KFD. What about applications that run
for longer without calling into KFD? This doesn't sound like a solution,
it's just a hack.
>
>
> I would like to avoid this and appreciate some pointers where i can
> put get_sync calls while unbinding. I have tried a number of places
> but saw some issues. So any help will be highly appreciated, to
> identify the proper logical inverse of kfd_bind_process_to_device.
kfd_bind_process_to_device is called when KFD starts using a device. It
only stops using that device when the process is destroyed. Therefore I
recommended moving the cleanup code into kfd_process_destroy_pdds, which
iterates over all devices (PDDs) during process termination.
Note that kfd_bind_process_to_device can be called many times for the
same device. If you need to keep usage counters balanced, you need extra
checks to make sure you only do runtime-PM stuff the first time it's
called for a particular device in a particular process.
Also, in kfd_process_destroy_pdds you may need to check whether
kfd_bind_process_to_device has been called for a particular PDD before
releasing runtime PM.
Regards,
Felix
>
>
>>
>> On 2020-01-27 20:29, 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 runtime power management.
>>>
>>> Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>
>>> ---
>>> 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 | 31
>>> +++++++++++++---------
>>> drivers/gpu/drm/amd/amdkfd/kfd_iommu.c | 5 +++-
>>> drivers/gpu/drm/amd/amdkfd/kfd_process.c | 19 ++++++++++---
>>> 6 files changed, 51 insertions(+), 28 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 0fa898d30207..3dce4a51e522 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
>>> @@ -123,8 +123,8 @@ 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);
>>> @@ -250,8 +250,8 @@ 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 d9e5eac182d3..787d49e9f4de 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> @@ -3314,7 +3314,7 @@ int amdgpu_device_suspend(struct drm_device
>>> *dev, bool fbcon)
>>> }
>>> }
>>> - amdgpu_amdkfd_suspend(adev);
>>> + amdgpu_amdkfd_suspend(adev, fbcon);
>>
>> The logic seems inverted here. There are four different pmops
>> callbacks that use different values for this parameter:
>>
>> * amdgpu_pmops_suspend: true
>> * amdgpu_pmops_freeze: true
>> * amdgpu_pmops_poweroff: true
>> * amdgpu_pmops_runtime_suspend: false
>>
>> It looks like runtime_suspend uses false, so you should pass the
>> run_pm parameter as !fbcon.
>
> Ok. will fix in v2.
>
>
>>
>>
>>> amdgpu_ras_suspend(adev);
>>> @@ -3398,7 +3398,7 @@ 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 2a9e40131735..e9f00c3a067a 100644
>>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_device.c
>>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
>>> @@ -23,6 +23,7 @@
>>> #include <linux/bsearch.h>
>>> #include <linux/pci.h>
>>> #include <linux/slab.h>
>>> +#include <linux/pm_runtime.h>
>>> #include "kfd_priv.h"
>>> #include "kfd_device_queue_manager.h"
>>> #include "kfd_pm4_headers_vi.h"
>>> @@ -710,7 +711,7 @@ 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, true);
>>> device_queue_manager_uninit(kfd->dqm);
>>> kfd_interrupt_exit(kfd);
>>> kfd_topology_remove_device(kfd);
>>> @@ -731,7 +732,7 @@ int kgd2kfd_pre_reset(struct kfd_dev *kfd)
>>> kfd->dqm->ops.pre_reset(kfd->dqm);
>>> - kgd2kfd_suspend(kfd);
>>> + kgd2kfd_suspend(kfd, true);
>>
>> This should use false. This is not runtime PM.
>>
>>
>>> kfd_signal_reset_event(kfd);
>>> return 0;
>>> @@ -765,21 +766,24 @@ 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) {
>>
>> This should be done for the non-runtime PM case: if (!run_pm).
>>
>>
>>> + /* For first KFD device suspend all the KFD processes */
>>> + if (atomic_inc_return(&kfd_locked) == 1)
>>> + kfd_suspend_all_processes();
>>> + }
>>> + pm_runtime_set_autosuspend_delay(kfd->ddev->dev, 5000);
>>> 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;
>>> @@ -790,10 +794,13 @@ 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) {
>>
>> Same as above.
>>
>>
>>> + 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_iommu.c
>>> b/drivers/gpu/drm/amd/amdkfd/kfd_iommu.c
>>> index 8d871514671e..6301d77ed3d6 100644
>>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_iommu.c
>>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_iommu.c
>>> @@ -25,6 +25,7 @@
>>> #include <linux/slab.h>
>>> #include <linux/pci.h>
>>> #include <linux/amd-iommu.h>
>>> +#include <linux/pm_runtime.h>
>>> #include "kfd_priv.h"
>>> #include "kfd_dbgmgr.h"
>>> #include "kfd_topology.h"
>>> @@ -134,8 +135,10 @@ void kfd_iommu_unbind_process(struct
>>> kfd_process *p)
>>> struct kfd_process_device *pdd;
>>> list_for_each_entry(pdd, &p->per_device_data, per_device_list)
>>> - if (pdd->bound == PDD_BOUND)
>>> + if (pdd->bound == PDD_BOUND) {
>>> amd_iommu_unbind_pasid(pdd->dev->pdev, p->pasid);
>>> + pm_runtime_set_autosuspend_delay(pdd->dev->ddev->dev, 5000);
>>
>> I don't think this is the right place. This code should only run on
>> APUs with IOMMUv2 enabled. Probably missing a check at the start of
>> the function. On kernels with IOMMU disabled, this source file is not
>> compiled at all.
>>
>> I think this code should go into kfd_process_destroy_pdds.
>
>
> Ok. will fix in v2. So can we consider this as logical inverse of
> bind_process_to_device?
>
>
>>
>>
>>> + }
>>> }
>>> /* Callback for process shutdown invoked by the IOMMU driver */
>>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>>> b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>>> index 25b90f70aecd..d19d5e97405c 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"
>>> @@ -843,15 +844,27 @@ struct kfd_process_device
>>> *kfd_bind_process_to_device(struct kfd_dev *dev,
>>> return ERR_PTR(-ENOMEM);
>>> }
>>> + err = pm_runtime_get_sync(dev->ddev->dev);
>>> + pm_runtime_set_autosuspend_delay(dev->ddev->dev, 60000);
>>
>> Why are you using a different hard-coded delay (60s?) here?
>
>
> It needs to be fixed. Explained above the reason for such deviation.
>
>
>>
>> Regards,
>> Felix
>>
>
> Thanks
> Rajneesh
>
>
>>> + 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;
>>> +out:
>>> + pm_runtime_mark_last_busy(dev->ddev->dev);
>>> + pm_runtime_put_autosuspend(dev->ddev->dev);
>>> +
>>> + if (!err)
>>> + return pdd;
>>> + else
>>> + return ERR_PTR(err);
>>> }
>>> struct kfd_process_device *kfd_get_first_process_device_data(
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