[PATCH v3 2/3] drm/amdkfd: Add process eviction counters to sysfs

Felix Kuehling felix.kuehling at amd.com
Thu Sep 17 14:32:41 UTC 2020


Am 2020-09-17 um 9:11 a.m. schrieb Cox, Philip:
> [AMD Official Use Only - Internal Distribution Only]
>
>>> +static struct attribute *procfs_stats_attrs[] = {
>>> +	NULL
>>> +};
>> We could probably use this to populate the attributes in stats automatically instead of calling sysfs_create_file and sysfs_remove_file manually. Then we may also not need the attr_evict attribute in the pdd.
>
> We use the attr_evict as an anchor to locate the pdd in kfd_procfs_stats_show().  So, if we use the default attributes, and drop the calls to sysfs_create_file, and sysfs_remove_file, it makes kfd_procfs_stats_show() much more complicated, as we then need to find the correct pdd without using the anchor attr_evict.
>
> Also, if we create the file via the default attributes, as you suggest, and don't drop the attr_evict, we get incorrect results.  
>
> The code is much cleaner I think leaving the calls to sysfs_create_file, and sysfs_remove_file() as they are, and leaving the default stats attributes NULL.  If some other stats are added later, that don't require the pdd, then they can be added to this structure, but I don't think the eviction stats should be.

Thanks. Makes sense. I expect that all the stats will need the PDD. They
are all per-process, per-device stats.

With the small nit-picks fixed, the patch is

Reviewed-by: Felix Kuehling <Felix.Kuehling at amd.com>

Regards,
  Felix


>
> -----Original Message-----
> From: Kuehling, Felix <Felix.Kuehling at amd.com> 
> Sent: Wednesday, September 16, 2020 6:46 PM
> To: Cox, Philip <Philip.Cox at amd.com>; amd-gfx at lists.freedesktop.org
> Cc: Tye, Tony <Tony.Tye at amd.com>; Morichetti, Laurent <Laurent.Morichetti at amd.com>; Kim, Jonathan <Jonathan.Kim at amd.com>; Errabolu, Ramesh <Ramesh.Errabolu at amd.com>
> Subject: Re: [PATCH v3 2/3] drm/amdkfd: Add process eviction counters to sysfs
>
> Some nit-picks and one more possible simplification inline. I want to make adding more stats later as painless as possible.
>
> Looks good otherwise.
>
>
> Am 2020-09-16 um 2:42 p.m. schrieb Philip Cox:
>> Add per-process eviction counters to sysfs to keep track of how many 
>> eviction events have happened for each process.
>>
>> v2: rename the stats dir, and track all evictions per process, per device.
>> v3: Simplify the stats kobject handling and cleanup.
>>
>> Signed-off-by: Philip Cox <Philip.Cox at amd.com>
>> ---
>>  .../drm/amd/amdkfd/kfd_device_queue_manager.c |  9 ++
>>  drivers/gpu/drm/amd/amdkfd/kfd_priv.h         |  9 +-
>>  drivers/gpu/drm/amd/amdkfd/kfd_process.c      | 97 +++++++++++++++++++
>>  3 files changed, 114 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c 
>> b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
>> index cafbc3aa980a..5b9e0df2a90e 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
>> @@ -653,6 +653,7 @@ static int evict_process_queues_nocpsch(struct device_queue_manager *dqm,
>>  	pr_info_ratelimited("Evicting PASID 0x%x queues\n",
>>  			    pdd->process->pasid);
>>  
>> +	pdd->last_evict_timestamp = get_jiffies_64();
>>  	/* Mark all queues as evicted. Deactivate all active queues on
>>  	 * the qpd.
>>  	 */
>> @@ -714,6 +715,7 @@ static int evict_process_queues_cpsch(struct device_queue_manager *dqm,
>>  		q->properties.is_active = false;
>>  		decrement_queue_count(dqm, q->properties.type);
>>  	}
>> +	pdd->last_evict_timestamp = get_jiffies_64();
>>  	retval = execute_queues_cpsch(dqm,
>>  				qpd->is_debug ?
>>  				KFD_UNMAP_QUEUES_FILTER_ALL_QUEUES :
>> @@ -732,6 +734,7 @@ static int restore_process_queues_nocpsch(struct device_queue_manager *dqm,
>>  	struct mqd_manager *mqd_mgr;
>>  	struct kfd_process_device *pdd;
>>  	uint64_t pd_base;
>> +	uint64_t eviction_duration;
>>  	int retval, ret = 0;
>>  
>>  	pdd = qpd_to_pdd(qpd);
>> @@ -799,6 +802,8 @@ static int restore_process_queues_nocpsch(struct device_queue_manager *dqm,
>>  			ret = retval;
>>  	}
>>  	qpd->evicted = 0;
>> +	eviction_duration = get_jiffies_64() - pdd->last_evict_timestamp;
>> +	atomic64_add(eviction_duration, &pdd->evict_duration_counter);
>>  out:
>>  	if (mm)
>>  		mmput(mm);
>> @@ -812,6 +817,7 @@ static int restore_process_queues_cpsch(struct device_queue_manager *dqm,
>>  	struct queue *q;
>>  	struct kfd_process_device *pdd;
>>  	uint64_t pd_base;
>> +	uint64_t eviction_duration;
>>  	int retval = 0;
>>  
>>  	pdd = qpd_to_pdd(qpd);
>> @@ -845,6 +851,9 @@ static int restore_process_queues_cpsch(struct device_queue_manager *dqm,
>>  	retval = execute_queues_cpsch(dqm,
>>  				KFD_UNMAP_QUEUES_FILTER_DYNAMIC_QUEUES, 0);
>>  	qpd->evicted = 0;
>> +	eviction_duration = get_jiffies_64() - pdd->last_evict_timestamp;
>> +	atomic64_add(eviction_duration, &pdd->evict_duration_counter);
>> +
>>  out:
>>  	dqm_unlock(dqm);
>>  	return retval;
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h 
>> b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
>> index 023629f28495..a500fe611b43 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
>> @@ -631,7 +631,7 @@ enum kfd_pdd_bound {
>>  	PDD_BOUND_SUSPENDED,
>>  };
>>  
>> -#define MAX_SYSFS_FILENAME_LEN 11
>> +#define MAX_SYSFS_FILENAME_LEN 15
>>  
>>  /*
>>   * SDMA counter runs at 100MHz frequency.
>> @@ -692,6 +692,13 @@ struct kfd_process_device {
>>  	uint64_t sdma_past_activity_counter;
>>  	struct attribute attr_sdma;
>>  	char sdma_filename[MAX_SYSFS_FILENAME_LEN];
>> +
>> +	/* Eviction activity tracking */
>> +	unsigned long last_evict_timestamp;
> get_jiffies_64 returns u64. You should use an equivalent type (uint64_t) here for consistency.
>
>
>> +	atomic64_t evict_duration_counter;
>> +	struct attribute attr_evict;
>> +
>> +	struct kobject *kobj_stats;
>>  };
>>  
>>  #define qpd_to_pdd(x) container_of(x, struct kfd_process_device, qpd) 
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c 
>> b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> index 1e15aa7d8ae8..b4ba394ad599 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
>> @@ -344,6 +344,26 @@ static ssize_t kfd_procfs_queue_show(struct 
>> kobject *kobj,
>>  
>>  	return 0;
>>  }
>> +static ssize_t kfd_procfs_stats_show(struct kobject *kobj,
>> +				     struct attribute *attr, char *buffer) {
>> +	if (strcmp(attr->name, "evicted_ms") == 0) {
>> +		struct kfd_process_device *pdd = container_of(attr,
>> +				struct kfd_process_device,
>> +				attr_evict);
>> +		uint64_t evict_jiffies;
>> +
>> +		evict_jiffies = atomic64_read(&pdd->evict_duration_counter);
>> +
>> +		return snprintf(buffer,
>> +				PAGE_SIZE,
>> +				"%llu\n",
>> +				jiffies64_to_msecs(evict_jiffies));
>> +	} else
>> +		pr_err("Invalid attribute");
>> +
>> +	return 0;
>> +}
>>  
>>  static struct attribute attr_queue_size = {
>>  	.name = "size",
>> @@ -376,6 +396,19 @@ static struct kobj_type procfs_queue_type = {
>>  	.default_attrs = procfs_queue_attrs,  };
>>  
>> +static const struct sysfs_ops procfs_stats_ops = {
>> +	.show = kfd_procfs_stats_show,
>> +};
>> +
>> +static struct attribute *procfs_stats_attrs[] = {
>> +	NULL
>> +};
> We could probably use this to populate the attributes in stats automatically instead of calling sysfs_create_file and sysfs_remove_file manually. Then we may also not need the attr_evict attribute in the pdd.
>
>
>> +
>> +static struct kobj_type procfs_stats_type = {
>> +	.sysfs_ops = &procfs_stats_ops,
>> +	.default_attrs = procfs_stats_attrs, };
>> +
>>  int kfd_procfs_add_queue(struct queue *q)  {
>>  	struct kfd_process *proc;
>> @@ -417,6 +450,60 @@ static int kfd_sysfs_create_file(struct kfd_process *p, struct attribute *attr,
>>  	return ret;
>>  }
>>  
>> +static int kfd_procfs_add_sysfs_stats(struct kfd_process *p) {
>> +	int ret = 0;
>> +	struct kfd_process_device *pdd;
>> +	char stats_dir_filename[MAX_SYSFS_FILENAME_LEN];
>> +
>> +	if (!p)
>> +		return -EINVAL;
>> +
>> +	if (!p->kobj)
>> +		return -EFAULT;
>> +
>> +	/*
>> +	 * Create sysfs files for each GPU:
>> +	 * - proc/<pid>/stats_<gpuid>/
>> +	 * - proc/<pid>/stats_<gpuid>/evicted_ms
>> +	 */
>> +	list_for_each_entry(pdd, &p->per_device_data, per_device_list) {
>> +		struct kobject *kobj_stats;
>> +
>> +
>> +		snprintf(stats_dir_filename, MAX_SYSFS_FILENAME_LEN,
>> +				"stats_%u", pdd->dev->id);
>> +		kobj_stats = kfd_alloc_struct(kobj_stats);
>> +		if (!kobj_stats) {
>> +			kfree(kobj_stats);
> If allocation failed, there is nothing to free.
>
> Regards,
>   Felix
>
>
>> +			return -ENOMEM;
>> +		}
>> +
>> +		ret = kobject_init_and_add(kobj_stats,
>> +						&procfs_stats_type,
>> +						p->kobj,
>> +						stats_dir_filename);
>> +
>> +		if (ret) {
>> +			pr_warn("Creating KFD proc/stats_%s folder failed",
>> +					stats_dir_filename);
>> +			kobject_put(kobj_stats);
>> +			goto err;
>> +		}
>> +
>> +		pdd->kobj_stats = kobj_stats;
>> +		pdd->attr_evict.name = "evicted_ms";
>> +		pdd->attr_evict.mode = KFD_SYSFS_FILE_MODE;
>> +		sysfs_attr_init(&pdd->attr_evict);
>> +		ret = sysfs_create_file(kobj_stats, &pdd->attr_evict);
>> +		if (ret)
>> +			pr_warn("Creating eviction stats for gpuid %d failed",
>> +				(int)pdd->dev->id);
>> +	}
>> +err:
>> +	return ret;
>> +}
>> +
>>  static int kfd_procfs_add_sysfs_files(struct kfd_process *p)  {
>>  	int ret = 0;
>> @@ -660,6 +747,11 @@ struct kfd_process *kfd_create_process(struct file *filep)
>>  		if (!process->kobj_queues)
>>  			pr_warn("Creating KFD proc/queues folder failed");
>>  
>> +		ret = kfd_procfs_add_sysfs_stats(process);
>> +		if (ret)
>> +			pr_warn("Creating sysfs stats dir for pid %d failed",
>> +				(int)process->lead_thread->pid);
>> +
>>  		ret = kfd_procfs_add_sysfs_files(process);
>>  		if (ret)
>>  			pr_warn("Creating sysfs usage file for pid %d failed", @@ -816,6 
>> +908,10 @@ static void kfd_process_wq_release(struct work_struct *work)
>>  		list_for_each_entry(pdd, &p->per_device_data, per_device_list) {
>>  			sysfs_remove_file(p->kobj, &pdd->attr_vram);
>>  			sysfs_remove_file(p->kobj, &pdd->attr_sdma);
>> +			sysfs_remove_file(p->kobj, &pdd->attr_evict);
>> +			kobject_del(pdd->kobj_stats);
>> +			kobject_put(pdd->kobj_stats);
>> +			pdd->kobj_stats = NULL;
>>  		}
>>  
>>  		kobject_del(p->kobj);
>> @@ -1125,6 +1221,7 @@ struct kfd_process_device *kfd_create_process_device_data(struct kfd_dev *dev,
>>  	pdd->runtime_inuse = false;
>>  	pdd->vram_usage = 0;
>>  	pdd->sdma_past_activity_counter = 0;
>> +	atomic64_set(&pdd->evict_duration_counter, 0);
>>  	list_add(&pdd->per_device_list, &p->per_device_data);
>>  
>>  	/* Init idr used for memory handle translation */


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