[PATCH 22/37] drm/amdkfd: Add perf counters to topology
Christian König
christian.koenig at amd.com
Mon Dec 11 17:26:12 UTC 2017
Am 11.12.2017 um 17:32 schrieb Oded Gabbay:
> On Mon, Dec 11, 2017 at 5:53 PM, Christian König
> <christian.koenig at amd.com> wrote:
>> Am 11.12.2017 um 16:23 schrieb Oded Gabbay:
>>> On Sat, Dec 9, 2017 at 6:09 AM, Felix Kuehling <Felix.Kuehling at amd.com>
>>> wrote:
>>>> From: Amber Lin <Amber.Lin at amd.com>
>>>>
>>>> For hardware blocks whose performance counters are accessed via MMIO
>>>> registers, KFD provides the support for those privileged blocks. IOMMU is
>>>> one of those privileged blocks. Most performance counter properties
>>>> required by Thunk are available at
>>>> /sys/bus/event_source/devices/amd_iommu.
>>>> This patch adds properties to topology in KFD sysfs for information not
>>>> available in /sys/bus/event_source/devices/amd_iommu. They are shown at
>>>> /sys/devices/virtual/kfd/kfd/topology/nodes/0/perf/iommu/ formatted as
>>>> /sys/devices/virtual/kfd/kfd/topology/nodes/0/perf/<block>/<property>,
>>>> i.e.
>>>> /sys/devices/virtual/kfd/kfd/topology/nodes/0/perf/iommu/max_concurrent.
>>>> For dGPUs, who don't have IOMMU, nothing appears under
>>>> /sys/devices/virtual/kfd/kfd/topology/nodes/0/perf.
>>> I don't feel comfortable with this patch. It seems to me you didn't
>>> have anywhere to put these counters so you just stuck them in a place
>>> the thunk already reads because it was "convenient" for you to do it.
>>> But, as you point out in a comment later, these counters have nothing
>>> to do with topology.
>>> So this just feels wrong and I would like to:
>>>
>>> a. get additional opinions on it. Christian ? Alex ? What do you think
>>> ?
>>
>> I agree that this looks odd.
>>
>> But that any device specific informations show up outside of
>> /sys/devices/pci0000:00... is strange to start with.
>>
>> Please don't tell me that we have build up a secondary topology parallel to
>> the linux device tree here?
> I hate to disappoint but the answer is that we do have a secondary
> topology dedicated to kfd under
> /sys/devices/virtual/kfd/kfd/topology/nodes/X
>
> This is part of the original design of the driver and it wasn't
> trivial to upstream, but at the end of the day it got upstreamed.
> I think the base argument was (and still is) that we expose a single
> char-dev for ALL the GPUs/APUs that are present in the system, and
> therefore, the thunk layer should get that information in one single
> place under the kfd driver folder in sysfs.
> I guess we could have done things differently, but that would have
> required more "integration" with the gfx driver at the time, which
> some people might have been thinking, at the time, to be more
> difficult then write write our own implementation.
> Anyway, that's all in the past and I doubt it will now change
> unless/until amdkfd is abolished and all functionality will move to
> amdgpu.
Well the requirement that KFD should be able to discover its devices
actually makes sense.
But we should probably make
/sys/devices/virtual/kfd/kfd/topology/nodes/X just a symlink to the
device directory in sysfs like everybody else does.
If that isn't possible because of file name clashes we should at least
point it to a subdirectory.
Regards,
Christian.
>
> Thanks,
> Oded
>> In other word for my Vega10 the real subdirectory for any device specific
>> config is:
>> ./devices/pci0000:00/0000:00:02.1/0000:01:00.0/0000:02:00.0/0000:03:00.0
>>
>> With the following files as symlink to it:
>> ./bus/pci/devices/0000:03:00.0
>> ./bus/pci/drivers/amdgpu/0000:03:00.0
>>
>>> How the GPU's GFX counters are exposed ?
>>
>> We discussed that internally but haven't decided on anything AFAIK.
>>
>>> b. Ask why not use IOCTL to get the counters ?
>>
>> Per process counters are directly readable inside the command submission
>> affecting them.
>>
>> Only the timer tick is exposed as IOCTL as well IIRC.
>>
>> Regards,
>> Christian.
>>
>>
>>> btw, I tried to search for other drivers that do this (expose perf
>>> counters in sysfs) and didn't find any (it wasn't an exhaustive search
>>> so I may have missed).
>>>
>>> Thanks,
>>> Oded
>>>
>>>
>>>
>>>
>>>> Signed-off-by: Amber Lin <Amber.Lin at amd.com>
>>>> Signed-off-by: Kent Russell <kent.russell at amd.com>
>>>> Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
>>>> ---
>>>> drivers/gpu/drm/amd/amdkfd/kfd_topology.c | 116
>>>> +++++++++++++++++++++++++++++-
>>>> drivers/gpu/drm/amd/amdkfd/kfd_topology.h | 13 ++++
>>>> 2 files changed, 127 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
>>>> b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
>>>> index 7fe7ee0..52d20f5 100644
>>>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
>>>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
>>>> @@ -104,6 +104,7 @@ static void kfd_release_topology_device(struct
>>>> kfd_topology_device *dev)
>>>> struct kfd_mem_properties *mem;
>>>> struct kfd_cache_properties *cache;
>>>> struct kfd_iolink_properties *iolink;
>>>> + struct kfd_perf_properties *perf;
>>>>
>>>> list_del(&dev->list);
>>>>
>>>> @@ -128,6 +129,13 @@ static void kfd_release_topology_device(struct
>>>> kfd_topology_device *dev)
>>>> kfree(iolink);
>>>> }
>>>>
>>>> + while (dev->perf_props.next != &dev->perf_props) {
>>>> + perf = container_of(dev->perf_props.next,
>>>> + struct kfd_perf_properties, list);
>>>> + list_del(&perf->list);
>>>> + kfree(perf);
>>>> + }
>>>> +
>>>> kfree(dev);
>>>> }
>>>>
>>>> @@ -162,6 +170,7 @@ struct kfd_topology_device
>>>> *kfd_create_topology_device(
>>>> INIT_LIST_HEAD(&dev->mem_props);
>>>> INIT_LIST_HEAD(&dev->cache_props);
>>>> INIT_LIST_HEAD(&dev->io_link_props);
>>>> + INIT_LIST_HEAD(&dev->perf_props);
>>>>
>>>> list_add_tail(&dev->list, device_list);
>>>>
>>>> @@ -328,6 +337,39 @@ static struct kobj_type cache_type = {
>>>> .sysfs_ops = &cache_ops,
>>>> };
>>>>
>>>> +/****** Sysfs of Performance Counters ******/
>>>> +
>>>> +struct kfd_perf_attr {
>>>> + struct kobj_attribute attr;
>>>> + uint32_t data;
>>>> +};
>>>> +
>>>> +static ssize_t perf_show(struct kobject *kobj, struct kobj_attribute
>>>> *attrs,
>>>> + char *buf)
>>>> +{
>>>> + struct kfd_perf_attr *attr;
>>>> +
>>>> + buf[0] = 0;
>>>> + attr = container_of(attrs, struct kfd_perf_attr, attr);
>>>> + if (!attr->data) /* invalid data for PMC */
>>>> + return 0;
>>>> + else
>>>> + return sysfs_show_32bit_val(buf, attr->data);
>>>> +}
>>>> +
>>>> +#define KFD_PERF_DESC(_name, _data) \
>>>> +{ \
>>>> + .attr = __ATTR(_name, 0444, perf_show, NULL), \
>>>> + .data = _data, \
>>>> +}
>>>> +
>>>> +static struct kfd_perf_attr perf_attr_iommu[] = {
>>>> + KFD_PERF_DESC(max_concurrent, 0),
>>>> + KFD_PERF_DESC(num_counters, 0),
>>>> + KFD_PERF_DESC(counter_ids, 0),
>>>> +};
>>>> +/****************************************/
>>>> +
>>>> static ssize_t node_show(struct kobject *kobj, struct attribute *attr,
>>>> char *buffer)
>>>> {
>>>> @@ -452,6 +494,7 @@ static void kfd_remove_sysfs_node_entry(struct
>>>> kfd_topology_device *dev)
>>>> struct kfd_iolink_properties *iolink;
>>>> struct kfd_cache_properties *cache;
>>>> struct kfd_mem_properties *mem;
>>>> + struct kfd_perf_properties *perf;
>>>>
>>>> if (dev->kobj_iolink) {
>>>> list_for_each_entry(iolink, &dev->io_link_props, list)
>>>> @@ -488,6 +531,16 @@ static void kfd_remove_sysfs_node_entry(struct
>>>> kfd_topology_device *dev)
>>>> dev->kobj_mem = NULL;
>>>> }
>>>>
>>>> + if (dev->kobj_perf) {
>>>> + list_for_each_entry(perf, &dev->perf_props, list) {
>>>> + kfree(perf->attr_group);
>>>> + perf->attr_group = NULL;
>>>> + }
>>>> + kobject_del(dev->kobj_perf);
>>>> + kobject_put(dev->kobj_perf);
>>>> + dev->kobj_perf = NULL;
>>>> + }
>>>> +
>>>> if (dev->kobj_node) {
>>>> sysfs_remove_file(dev->kobj_node, &dev->attr_gpuid);
>>>> sysfs_remove_file(dev->kobj_node, &dev->attr_name);
>>>> @@ -504,8 +557,10 @@ static int kfd_build_sysfs_node_entry(struct
>>>> kfd_topology_device *dev,
>>>> struct kfd_iolink_properties *iolink;
>>>> struct kfd_cache_properties *cache;
>>>> struct kfd_mem_properties *mem;
>>>> + struct kfd_perf_properties *perf;
>>>> int ret;
>>>> - uint32_t i;
>>>> + uint32_t i, num_attrs;
>>>> + struct attribute **attrs;
>>>>
>>>> if (WARN_ON(dev->kobj_node))
>>>> return -EEXIST;
>>>> @@ -534,6 +589,10 @@ static int kfd_build_sysfs_node_entry(struct
>>>> kfd_topology_device *dev,
>>>> if (!dev->kobj_iolink)
>>>> return -ENOMEM;
>>>>
>>>> + dev->kobj_perf = kobject_create_and_add("perf", dev->kobj_node);
>>>> + if (!dev->kobj_perf)
>>>> + return -ENOMEM;
>>>> +
>>>> /*
>>>> * Creating sysfs files for node properties
>>>> */
>>>> @@ -611,7 +670,33 @@ static int kfd_build_sysfs_node_entry(struct
>>>> kfd_topology_device *dev,
>>>> if (ret < 0)
>>>> return ret;
>>>> i++;
>>>> -}
>>>> + }
>>>> +
>>>> + /* All hardware blocks have the same number of attributes. */
>>>> + num_attrs = sizeof(perf_attr_iommu)/sizeof(struct kfd_perf_attr);
>>>> + list_for_each_entry(perf, &dev->perf_props, list) {
>>>> + perf->attr_group = kzalloc(sizeof(struct kfd_perf_attr)
>>>> + * num_attrs + sizeof(struct attribute_group),
>>>> + GFP_KERNEL);
>>>> + if (!perf->attr_group)
>>>> + return -ENOMEM;
>>>> +
>>>> + attrs = (struct attribute **)(perf->attr_group + 1);
>>>> + if (!strcmp(perf->block_name, "iommu")) {
>>>> + /* Information of IOMMU's num_counters and counter_ids is
>>>> shown
>>>> + * under /sys/bus/event_source/devices/amd_iommu. We
>>>> don't
>>>> + * duplicate here.
>>>> + */
>>>> + perf_attr_iommu[0].data = perf->max_concurrent;
>>>> + for (i = 0; i < num_attrs; i++)
>>>> + attrs[i] = &perf_attr_iommu[i].attr.attr;
>>>> + }
>>>> + perf->attr_group->name = perf->block_name;
>>>> + perf->attr_group->attrs = attrs;
>>>> + ret = sysfs_create_group(dev->kobj_perf,
>>>> perf->attr_group);
>>>> + if (ret < 0)
>>>> + return ret;
>>>> + }
>>>>
>>>> return 0;
>>>> }
>>>> @@ -778,6 +863,29 @@ static void find_system_memory(const struct
>>>> dmi_header *dm,
>>>> }
>>>> }
>>>> }
>>>> +
>>>> +/*
>>>> + * Performance counters information is not part of CRAT but we would
>>>> like to
>>>> + * put them in the sysfs under topology directory for Thunk to get the
>>>> data.
>>>> + * This function is called before updating the sysfs.
>>>> + */
>>>> +static int kfd_add_perf_to_topology(struct kfd_topology_device *kdev)
>>>> +{
>>>> + struct kfd_perf_properties *props;
>>>> +
>>>> + if (amd_iommu_pc_supported()) {
>>>> + props = kfd_alloc_struct(props);
>>>> + if (!props)
>>>> + return -ENOMEM;
>>>> + strcpy(props->block_name, "iommu");
>>>> + props->max_concurrent = amd_iommu_pc_get_max_banks(0) *
>>>> + amd_iommu_pc_get_max_counters(0); /* assume one
>>>> iommu */
>>>> + list_add_tail(&props->list, &kdev->perf_props);
>>>> + }
>>>> +
>>>> + return 0;
>>>> +}
>>>> +
>>>> /* kfd_add_non_crat_information - Add information that is not currently
>>>> * defined in CRAT but is necessary for KFD topology
>>>> * @dev - topology device to which addition info is added
>>>> @@ -860,6 +968,10 @@ int kfd_topology_init(void)
>>>> }
>>>> }
>>>>
>>>> + kdev = list_first_entry(&temp_topology_device_list,
>>>> + struct kfd_topology_device, list);
>>>> + kfd_add_perf_to_topology(kdev);
>>>> +
>>>> down_write(&topology_lock);
>>>> kfd_topology_update_device_list(&temp_topology_device_list,
>>>> &topology_device_list);
>>>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.h
>>>> b/drivers/gpu/drm/amd/amdkfd/kfd_topology.h
>>>> index 55de56f..b9f3142 100644
>>>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.h
>>>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.h
>>>> @@ -134,6 +134,13 @@ struct kfd_iolink_properties {
>>>> struct attribute attr;
>>>> };
>>>>
>>>> +struct kfd_perf_properties {
>>>> + struct list_head list;
>>>> + char block_name[16];
>>>> + uint32_t max_concurrent;
>>>> + struct attribute_group *attr_group;
>>>> +};
>>>> +
>>>> struct kfd_topology_device {
>>>> struct list_head list;
>>>> uint32_t gpu_id;
>>>> @@ -144,11 +151,13 @@ struct kfd_topology_device {
>>>> struct list_head cache_props;
>>>> uint32_t io_link_count;
>>>> struct list_head io_link_props;
>>>> + struct list_head perf_props;
>>>> struct kfd_dev *gpu;
>>>> struct kobject *kobj_node;
>>>> struct kobject *kobj_mem;
>>>> struct kobject *kobj_cache;
>>>> struct kobject *kobj_iolink;
>>>> + struct kobject *kobj_perf;
>>>> struct attribute attr_gpuid;
>>>> struct attribute attr_name;
>>>> struct attribute attr_props;
>>>> @@ -173,4 +182,8 @@ struct kfd_topology_device
>>>> *kfd_create_topology_device(
>>>> struct list_head *device_list);
>>>> void kfd_release_topology_device_list(struct list_head *device_list);
>>>>
>>>> +extern bool amd_iommu_pc_supported(void);
>>>> +extern u8 amd_iommu_pc_get_max_banks(u16 devid);
>>>> +extern u8 amd_iommu_pc_get_max_counters(u16 devid);
>>>> +
>>>> #endif /* __KFD_TOPOLOGY_H__ */
>>>> --
>>>> 2.7.4
>>>>
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