[RFC 2/5] drm/i915: Expose list of clients in sysfs

Tvrtko Ursulin
2018-02-14T18:50:49Z

From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Expose a list of clients with open file handles in sysfs.

This will be a basis for a top-like utility showing per-client and per-
engine GPU load.

Currently we only expose each client's pid and name under opaque numbered
directories in /sys/class/drm/card0/clients/.

For instance:

/sys/class/drm/card0/clients/3/name: Xorg
/sys/class/drm/card0/clients/3/pid: 5664

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
drivers/gpu/drm/i915/i915_drv.h | 13 +++++
drivers/gpu/drm/i915/i915_gem.c | 112 +++++++++++++++++++++++++++++++++++---
drivers/gpu/drm/i915/i915_sysfs.c | 8 +++
3 files changed, 126 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 70cf289855af..2133e67f5fbc 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -345,6 +345,16 @@ struct drm_i915_file_private {
*/
#define I915_MAX_CLIENT_CONTEXT_BANS 3
atomic_t context_bans;
+
+ unsigned int client_sysfs_id;
+ unsigned int client_pid;
+ char *client_name;
+ struct kobject *client_root;
+
+ struct {
+ struct device_attribute pid;
+ struct device_attribute name;
+ } attr;
};

/* Interface history:
@@ -2365,6 +2375,9 @@ struct drm_i915_private {

struct i915_pmu pmu;

+ struct kobject *clients_root;
+ atomic_t client_serial;
+
/*
* NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
* will be rejected. Instead look for a better place.
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index fc68b35854df..24607bce2efe 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -5613,6 +5613,89 @@ int i915_gem_freeze_late(struct drm_i915_private *dev_priv)
return 0;
}

+static ssize_t
+show_client_name(struct device *kdev, struct device_attribute *attr, char *buf)
+{
+ struct drm_i915_file_private *file_priv =
+ container_of(attr, struct drm_i915_file_private, attr.name);
+
+ return snprintf(buf, PAGE_SIZE, "%s", file_priv->client_name);
+}
+
+static ssize_t
+show_client_pid(struct device *kdev, struct device_attribute *attr, char *buf)
+{
+ struct drm_i915_file_private *file_priv =
+ container_of(attr, struct drm_i915_file_private, attr.pid);
+
+ return snprintf(buf, PAGE_SIZE, "%u", file_priv->client_pid);
+}
+
+static int
+i915_gem_add_client(struct drm_i915_private *i915,
+ struct drm_i915_file_private *file_priv,
+ struct task_struct *task,
+ unsigned int serial)
+{
+ int ret = -ENOMEM;
+ struct device_attribute *attr;
+ char id[32];
+
+ file_priv->client_name = kstrdup(task->comm, GFP_KERNEL);
+ if (!file_priv->client_name)
+ goto err_name;
+
+ snprintf(id, sizeof(id), "%u", serial);
+ file_priv->client_root = kobject_create_and_add(id,
+ i915->clients_root);
+ if (!file_priv->client_root)
+ goto err_client;
+
+ attr = &file_priv->attr.name;
+ attr->attr.name = "name";
+ attr->attr.mode = 0444;
+ attr->show = show_client_name;
+
+ ret = sysfs_create_file(file_priv->client_root,
+ (struct attribute *)attr);
+ if (ret)
+ goto err_attr_name;
+
+ attr = &file_priv->attr.pid;
+ attr->attr.name = "pid";
+ attr->attr.mode = 0444;
+ attr->show = show_client_pid;
+
+ ret = sysfs_create_file(file_priv->client_root,
+ (struct attribute *)attr);
+ if (ret)
+ goto err_attr_pid;
+
+ file_priv->client_pid = pid_nr(get_task_pid(task, PIDTYPE_PID));
+
+ return 0;
+
+err_attr_pid:
+ sysfs_remove_file(file_priv->client_root,
+ (struct attribute *)&file_priv->attr.name);
+err_attr_name:
+ kobject_put(file_priv->client_root);
+err_client:
+ kfree(file_priv->client_name);
+err_name:
+ return ret;
+}
+
+static void i915_gem_remove_client(struct drm_i915_file_private *file_priv)
+{
+ sysfs_remove_file(file_priv->client_root,
+ (struct attribute *)&file_priv->attr.pid);
+ sysfs_remove_file(file_priv->client_root,
+ (struct attribute *)&file_priv->attr.name);
+ kobject_put(file_priv->client_root);
+ kfree(file_priv->client_name);
+}
+
void i915_gem_release(struct drm_device *dev, struct drm_file *file)
{
struct drm_i915_file_private *file_priv = file->driver_priv;
@@ -5626,32 +5709,47 @@ void i915_gem_release(struct drm_device *dev, struct drm_file *file)
list_for_each_entry(request, &file_priv->mm.request_list, client_link)
request->file_priv = NULL;
spin_unlock(&file_priv->mm.lock);
+
+ i915_gem_remove_client(file_priv);
}

int i915_gem_open(struct drm_i915_private *i915, struct drm_file *file)
{
+ int ret = -ENOMEM;
struct drm_i915_file_private *file_priv;
- int ret;

DRM_DEBUG("\n");

file_priv = kzalloc(sizeof(*file_priv), GFP_KERNEL);
if (!file_priv)
- return -ENOMEM;
+ goto err_alloc;
+
+ file_priv->client_sysfs_id = atomic_inc_return(&i915->client_serial);
+ ret = i915_gem_add_client(i915, file_priv, current,
+ file_priv->client_sysfs_id);
+ if (ret)
+ goto err_client;

file->driver_priv = file_priv;
+ ret = i915_gem_context_open(i915, file);
+ if (ret)
+ goto err_context;
+
file_priv->dev_priv = i915;
file_priv->file = file;
+ file_priv->bsd_engine = -1;

spin_lock_init(&file_priv->mm.lock);
INIT_LIST_HEAD(&file_priv->mm.request_list);

- file_priv->bsd_engine = -1;
-
- ret = i915_gem_context_open(i915, file);
- if (ret)
- kfree(file_priv);
+ return 0;

+err_context:
+ i915_gem_remove_client(file_priv);
+err_client:
+ atomic_dec(&i915->client_serial);
+ kfree(file_priv);
+err_alloc:
return ret;
}

diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index b33d2158c234..6cf032bc1573 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -575,6 +575,11 @@ void i915_setup_sysfs(struct drm_i915_private *dev_priv)
struct device *kdev = dev_priv->drm.primary->kdev;
int ret;

+ dev_priv->clients_root =
+ kobject_create_and_add("clients", &kdev->kobj);
+ if (!dev_priv->clients_root)
+ DRM_ERROR("Per-client sysfs setup failed\n");
+
#ifdef CONFIG_PM
if (HAS_RC6(dev_priv)) {
ret = sysfs_merge_group(&kdev->kobj,
@@ -635,4 +640,7 @@ void i915_teardown_sysfs(struct drm_i915_private *dev_priv)
sysfs_unmerge_group(&kdev->kobj, &rc6_attr_group);
sysfs_unmerge_group(&kdev->kobj, &rc6p_attr_group);
#endif
+
+ if (dev_priv->clients_root)
+ kobject_put(dev_priv->clients_root);
}
--
2.14.1