[PATCH v3 6/7] drm: Add fdinfo memory stats

Rob Clark
2023-04-11T22:58:28Z

From: Rob Clark <robdclark@chromium.org>

Add support to dump GEM stats to fdinfo.

v2: Fix typos, change size units to match docs, use div_u64
v3: Do it in core

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
---
Documentation/gpu/drm-usage-stats.rst | 21 ++++++++
drivers/gpu/drm/drm_file.c | 76 +++++++++++++++++++++++++++
include/drm/drm_file.h | 1 +
include/drm/drm_gem.h | 19 +++++++
4 files changed, 117 insertions(+)

diff --git a/Documentation/gpu/drm-usage-stats.rst b/Documentation/gpu/drm-usage-stats.rst
index b46327356e80..b5e7802532ed 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 purgeable.
+
+- 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 37dfaa6be560..46fdd843bb3a 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"
@@ -871,6 +872,79 @@ 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[] = {"", " KiB", " MiB"};
+ unsigned u;
+
+ for (u = 0; u < ARRAY_SIZE(units) - 1; u++) {
+ if (sz < SZ_1K)
+ break;
+ sz = div_u64(sz, SZ_1K);
+ }
+
+ drm_printf(p, "%s:\t%zu%s\n", stat, sz, units[u]);
+}
+
+static void print_memory_stats(struct drm_printer *p, struct drm_file *file)
+{
+ struct drm_gem_object *obj;
+ struct {
+ size_t shared;
+ size_t private;
+ size_t resident;
+ size_t purgeable;
+ size_t active;
+ } size = {0};
+ bool has_status = false;
+ int id;
+
+ spin_lock(&file->table_lock);
+ idr_for_each_entry (&file->object_idr, obj, id) {
+ enum drm_gem_object_status s = 0;
+
+ if (obj->funcs && obj->funcs->status) {
+ s = obj->funcs->status(obj);
+ has_status = true;
+ }
+
+ if (obj->handle_count > 1) {
+ size.shared += obj->size;
+ } else {
+ size.private += obj->size;
+ }
+
+ if (s & DRM_GEM_OBJECT_RESIDENT) {
+ size.resident += obj->size;
+ } else {
+ /* If already purged or not yet backed by pages, don't
+ * count it as purgeable:
+ */
+ s &= ~DRM_GEM_OBJECT_PURGEABLE;
+ }
+
+ if (!dma_resv_test_signaled(obj->resv, dma_resv_usage_rw(true))) {
+ size.active += obj->size;
+
+ /* If still active, don't count as purgeable: */
+ 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);
+ print_size(p, "drm-active-memory", size.active);
+
+ if (has_status) {
+ print_size(p, "drm-resident-memory", size.resident);
+ print_size(p, "drm-purgeable-memory", size.purgeable);
+ }
+}
+
/**
* drm_fop_show_fdinfo - helper for drm file fops
* @seq_file: output stream
@@ -904,6 +978,8 @@ void drm_fop_show_fdinfo(struct seq_file *m, struct file *f)

if (dev->driver->show_fdinfo)
dev->driver->show_fdinfo(&p, file);
+
+ print_memory_stats(&p, file);
}
EXPORT_SYMBOL(drm_fop_show_fdinfo);

diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index dfa995b787e1..e5b40084538f 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;

diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 189fd618ca65..213917bb6b11 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -42,6 +42,14 @@
struct iosys_map;
struct drm_gem_object;

+/**
+ * enum drm_gem_object_status - bitmask of object state for fdinfo reporting
+ */
+enum drm_gem_object_status {
+ DRM_GEM_OBJECT_RESIDENT = BIT(0),
+ DRM_GEM_OBJECT_PURGEABLE = BIT(1),
+};
+
/**
* struct drm_gem_object_funcs - GEM object functions
*/
@@ -174,6 +182,17 @@ struct drm_gem_object_funcs {
*/
int (*evict)(struct drm_gem_object *obj);

+ /**
+ * @status:
+ *
+ * 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 destruction.
+ */
+ enum drm_gem_object_status (*status)(struct drm_gem_object *obj);
+
/**
* @vm_ops:
*
--
2.39.2