[RFC 1/2] drm: Add fdinfo memory stats

Rob Clark
2023-04-06T22:00:28Z

From: Rob Clark <robdclark@chromium.org>

Add a helper to dump memory stats to fdinfo. For the things the drm
core isn't aware of, use a callback.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
Documentation/gpu/drm-usage-stats.rst | 21 +++++++
drivers/gpu/drm/drm_file.c | 79 +++++++++++++++++++++++++++
include/drm/drm_file.h | 10 ++++
3 files changed, 110 insertions(+)

diff --git a/Documentation/gpu/drm-usage-stats.rst b/Documentation/gpu/drm-usage-stats.rst
index b46327356e80..56e3c95b6e0a 100644
--- a/Documentation/gpu/drm-usage-stats.rst
+++ b/Documentation/gpu/drm-usage-stats.rst
@@ -105,6 +105,27 @@ 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.

+- drm-shared-memory: <uint> [KiB|MiB]
+
+The total size of buffers that are shared with another file (ie. have more
+than a single handle).
+
+- drm-private-memory: <uint> [KiB|MiB]
+
+The total size of buffers that are not shared with another file.
+
+- drm-resident-memory: <uint> [KiB|MiB]
+
+The total size of buffers that are resident in system memory.
+
+- drm-purgeable-memory: <uint> [KiB|MiB]
+
+The total size of buffers that are purgable.
+
+- drm-active-memory: <uint> [KiB|MiB]
+
+The total size of buffers that are active on one or more rings.
+
- drm-cycles-<str> <uint>

Engine identifier string must be the same as the one specified in the
diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index a51ff8cee049..21911d6ff38d 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -42,6 +42,7 @@
#include <drm/drm_client.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
+#include <drm/drm_gem.h>
#include <drm/drm_print.h>

#include "drm_crtc_internal.h"
@@ -868,6 +869,84 @@ void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
}
EXPORT_SYMBOL(drm_send_event);

+static void print_size(struct drm_printer *p, const char *stat, size_t sz)
+{
+ const char *units[] = {"B", "KiB", "MiB", "GiB"};
+ unsigned u;
+
+ for (u = 0; u < ARRAY_SIZE(units) - 1; u++) {
+ if (sz < SZ_1K)
+ break;
+ sz /= SZ_1K;
+ }
+
+ drm_printf(p, "%s:\t%lu %s\n", stat, sz, units[u]);
+}
+
+/**
+ * drm_print_memory_stats - Helper to print standard fdinfo memory stats
+ * @file: the DRM file
+ * @p: the printer to print output to
+ * @status: callback to get driver tracked object status
+ *
+ * Helper to iterate over GEM objects with a handle allocated in the specified
+ * file. The optional status callback can return additional object state which
+ * determines which stats the object is counted against. The callback is called
+ * under table_lock. Racing against object status change is "harmless", and the
+ * callback can expect to not race against object destroy.
+ */
+void drm_print_memory_stats(struct drm_file *file, struct drm_printer *p,
+ enum drm_gem_object_status (*status)(struct drm_gem_object *))
+{
+ struct drm_gem_object *obj;
+ struct {
+ size_t shared;
+ size_t private;
+ size_t resident;
+ size_t purgeable;
+ size_t active;
+ } size = {0};
+ int id;
+
+ spin_lock(&file->table_lock);
+ idr_for_each_entry (&file->object_idr, obj, id) {
+ enum drm_gem_object_status s = 0;
+
+ if (status)
+ s = status(obj);
+
+ if (obj->handle_count > 1) {
+ size.shared += obj->size;
+ } else {
+ size.private += obj->size;
+ }
+
+ if (s & DRM_GEM_OBJECT_RESIDENT) {
+ size.resident += obj->size;
+ s &= ~DRM_GEM_OBJECT_PURGEABLE;
+ }
+
+ if (s & DRM_GEM_OBJECT_ACTIVE) {
+ size.active += obj->size;
+ s &= ~DRM_GEM_OBJECT_PURGEABLE;
+ }
+
+ if (s & DRM_GEM_OBJECT_PURGEABLE)
+ size.purgeable += obj->size;
+ }
+ spin_unlock(&file->table_lock);
+
+ print_size(p, "drm-shared-memory", size.shared);
+ print_size(p, "drm-private-memory", size.private);
+
+ if (status) {
+ print_size(p, "drm-resident-memory", size.resident);
+ print_size(p, "drm-purgeable-memory", size.purgeable);
+ print_size(p, "drm-active-memory", size.active);
+ }
+}
+EXPORT_SYMBOL(drm_print_memory_stats);
+
/**
* mock_drm_getfile - Create a new struct file for the drm device
* @minor: drm minor to wrap (e.g. #drm_device.primary)
diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index 0d1f853092ab..7bd8a1374f39 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -41,6 +41,7 @@
struct dma_fence;
struct drm_file;
struct drm_device;
+struct drm_printer;
struct device;
struct file;

@@ -438,6 +439,15 @@ void drm_send_event_timestamp_locked(struct drm_device *dev,
struct drm_pending_event *e,
ktime_t timestamp);

+enum drm_gem_object_status {
+ DRM_GEM_OBJECT_RESIDENT = BIT(0),
+ DRM_GEM_OBJECT_PURGEABLE = BIT(1),
+ DRM_GEM_OBJECT_ACTIVE = BIT(2),
+};
+
+void drm_print_memory_stats(struct drm_file *file, struct drm_printer *p,
+ enum drm_gem_object_status (*status)(struct drm_gem_object *));
+
struct file *mock_drm_getfile(struct drm_minor *minor, unsigned int flags);

#endif /* _DRM_FILE_H_ */
--
2.39.2