[PATCH 22/37] drm/amdkfd: Add perf counters to topology
Oded Gabbay
oded.gabbay at gmail.com
Mon Dec 11 15:23:26 UTC 2017
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
? How the GPU's GFX counters are exposed ?
b. Ask why not use IOCTL to get the counters ?
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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