[PATCH 7/7] drm/i915: Expose client engine utilisation via fdinfo

Tvrtko Ursulin
2021-09-22T15:52:25Z

Similar to AMD commit
874442541133 ("drm/amdgpu: Add show_fdinfo() interface"), using the
infrastructure added in previous patches, we add basic client info
and GPU engine utilisation for i915.

Example of the output:

pos: 0
flags: 0100002
mnt_id: 21
drm-driver: i915
drm-pdev: 0000:00:02.0
drm-client-id: 7
drm-engine-render: 9288864723 ns
drm-engine-copy: 2035071108 ns
drm-engine-video: 0 ns
drm-engine-video-enhance: 0 ns

v2:
* Update for removal of name and pid.

v3:
* Use drm_driver.name.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: David M Nieto <David.Nieto@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Acked-by: Christian König <christian.koenig@amd.com>
---
Documentation/gpu/drm-usage-stats.rst | 6 +++
Documentation/gpu/i915.rst | 27 ++++++++++
drivers/gpu/drm/i915/i915_drm_client.c | 73 ++++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_drm_client.h | 4 ++
drivers/gpu/drm/i915/i915_drv.c | 3 ++
5 files changed, 113 insertions(+)

diff --git a/Documentation/gpu/drm-usage-stats.rst b/Documentation/gpu/drm-usage-stats.rst
index c669026be244..6952f8389d07 100644
--- a/Documentation/gpu/drm-usage-stats.rst
+++ b/Documentation/gpu/drm-usage-stats.rst
@@ -95,3 +95,9 @@ object belong to this client, in the respective memory region.

Default unit shall be bytes with optional unit specifiers of 'KiB' or 'MiB'
indicating kibi- or mebi-bytes.
+
+===============================
+Driver specific implementations
+===============================
+
+:ref:`i915-usage-stats`
diff --git a/Documentation/gpu/i915.rst b/Documentation/gpu/i915.rst
index 311e10400708..36cd6f74fb1b 100644
--- a/Documentation/gpu/i915.rst
+++ b/Documentation/gpu/i915.rst
@@ -700,3 +700,30 @@ The style guide for ``i915_reg.h``.

.. kernel-doc:: drivers/gpu/drm/i915/i915_reg.h
:doc: The i915 register macro definition style guide
+
+.. _i915-usage-stats:
+
+i915 DRM client usage stats implementation
+==========================================
+
+The drm/i915 driver implements the DRM client usage stats specification as
+documented in :ref:`drm-client-usage-stats`.
+
+Example of the output showing the implemented key value pairs and entirety of
+the currenly possible format options:
+
+::
+
+ pos: 0
+ flags: 0100002
+ mnt_id: 21
+ drm-driver: i915
+ drm-pdev: 0000:00:02.0
+ drm-client-id: 7
+ drm-engine-render: 9288864723 ns
+ drm-engine-copy: 2035071108 ns
+ drm-engine-video: 0 ns
+ drm-engine-video-enhance: 0 ns
+
+Possible `drm-engine-` key names are: `render`, `copy`, `video` and
+`video-enhance`.
diff --git a/drivers/gpu/drm/i915/i915_drm_client.c b/drivers/gpu/drm/i915/i915_drm_client.c
index 91a8559bebf7..06dbd20ce763 100644
--- a/drivers/gpu/drm/i915/i915_drm_client.c
+++ b/drivers/gpu/drm/i915/i915_drm_client.c
@@ -7,6 +7,11 @@
#include <linux/slab.h>
#include <linux/types.h>

+#include <uapi/drm/i915_drm.h>
+
+#include <drm/drm_print.h>
+
+#include "gem/i915_gem_context.h"
#include "i915_drm_client.h"
#include "i915_gem.h"
#include "i915_utils.h"
@@ -68,3 +73,71 @@ void i915_drm_clients_fini(struct i915_drm_clients *clients)
GEM_BUG_ON(!xa_empty(&clients->xarray));
xa_destroy(&clients->xarray);
}
+
+#ifdef CONFIG_PROC_FS
+static const char * const uabi_class_names[] = {
+ [I915_ENGINE_CLASS_RENDER] = "render",
+ [I915_ENGINE_CLASS_COPY] = "copy",
+ [I915_ENGINE_CLASS_VIDEO] = "video",
+ [I915_ENGINE_CLASS_VIDEO_ENHANCE] = "video-enhance",
+};
+
+static u64 busy_add(struct i915_gem_context *ctx, unsigned int class)
+{
+ struct i915_gem_engines_iter it;
+ struct intel_context *ce;
+ u64 total = 0;
+
+ for_each_gem_engine(ce, rcu_dereference(ctx->engines), it) {
+ if (ce->engine->uabi_class != class)
+ continue;
+
+ total += intel_context_get_total_runtime_ns(ce);
+ }
+
+ return total;
+}
+
+static void
+show_client_class(struct seq_file *m,
+ struct i915_drm_client *client,
+ unsigned int class)
+{
+ const struct list_head *list = &client->ctx_list;
+ u64 total = atomic64_read(&client->past_runtime[class]);
+ struct i915_gem_context *ctx;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(ctx, list, client_link)
+ total += busy_add(ctx, class);
+ rcu_read_unlock();
+
+ return seq_printf(m, "drm-engine-%s:\t%llu ns\n",
+ uabi_class_names[class], total);
+}
+
+void i915_drm_client_fdinfo(struct seq_file *m, struct file *f)
+{
+ struct drm_file *file = f->private_data;
+ struct drm_i915_file_private *file_priv = file->driver_priv;
+ struct drm_i915_private *i915 = file_priv->dev_priv;
+ struct i915_drm_client *client = file_priv->client;
+ struct pci_dev *pdev = to_pci_dev(i915->drm.dev);
+ unsigned int i;
+
+ /*
+ * ******************************************************************
+ * For text output format description please see drm-usage-stats.rst!
+ * ******************************************************************
+ */
+
+ seq_printf(m, "drm-driver:\t%s\n", i915->drm.driver->name);
+ seq_printf(m, "drm-pdev:\t%04x:%02x:%02x.%d\n",
+ pci_domain_nr(pdev->bus), pdev->bus->number,
+ PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
+ seq_printf(m, "drm-client-id:\t%u\n", client->id);
+
+ for (i = 0; i < ARRAY_SIZE(uabi_class_names); i++)
+ show_client_class(m, client, i);
+}
+#endif
diff --git a/drivers/gpu/drm/i915/i915_drm_client.h b/drivers/gpu/drm/i915/i915_drm_client.h
index 7416e18aa33c..d96d6a06302e 100644
--- a/drivers/gpu/drm/i915/i915_drm_client.h
+++ b/drivers/gpu/drm/i915/i915_drm_client.h
@@ -57,6 +57,10 @@ static inline void i915_drm_client_put(struct i915_drm_client *client)

struct i915_drm_client *i915_drm_client_add(struct i915_drm_clients *clients);

+#ifdef CONFIG_PROC_FS
+void i915_drm_client_fdinfo(struct seq_file *m, struct file *f);
+#endif
+
void i915_drm_clients_fini(struct i915_drm_clients *clients);

#endif /* !__I915_DRM_CLIENT_H__ */
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 6418f3dbdad0..8ab0d49fd98a 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1711,6 +1711,9 @@ static const struct file_operations i915_driver_fops = {
.read = drm_read,
.compat_ioctl = i915_ioc32_compat_ioctl,
.llseek = noop_llseek,
+#ifdef CONFIG_PROC_FS
+ .show_fdinfo = i915_drm_client_fdinfo,
+#endif
};

static int
--
2.30.2