[PATCH RFC v4 06/16] drm, cgroup: Add GEM buffer allocation count stats

[Kenny Ho]

drm.buffer.count.stats
        A read-only flat-keyed file which exists on all cgroups.  Each
        entry is keyed by the drm device's major:minor.

        Total number of GEM buffer allocated.

Change-Id: Id3e1809d5fee8562e47a7d2b961688956d844ec6
Signed-off-by: Kenny Ho <Kenny.Ho at amd.com>
---
 Documentation/admin-guide/cgroup-v2.rst |  6 ++++++
 include/linux/cgroup_drm.h              |  3 +++
 kernel/cgroup/drm.c                     | 22 +++++++++++++++++++---
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 8588a0ffc69d..4dc72339a9b6 100644
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -1913,6 +1913,12 @@ DRM Interface Files
 
 	Largest (high water mark) GEM buffer allocated in bytes.
 
+  drm.buffer.count.stats
+	A read-only flat-keyed file which exists on all cgroups.  Each
+	entry is keyed by the drm device's major:minor.
+
+	Total number of GEM buffer allocated.
+
 GEM Buffer Ownership
 ~~~~~~~~~~~~~~~~~~~~
 
diff --git a/include/linux/cgroup_drm.h b/include/linux/cgroup_drm.h
index 974d390cfa4f..972f7aa975b5 100644
--- a/include/linux/cgroup_drm.h
+++ b/include/linux/cgroup_drm.h
@@ -16,6 +16,7 @@
 enum drmcg_res_type {
 	DRMCG_TYPE_BO_TOTAL,
 	DRMCG_TYPE_BO_PEAK,
+	DRMCG_TYPE_BO_COUNT,
 	__DRMCG_TYPE_LAST,
 };
 
@@ -27,6 +28,8 @@ struct drmcg_device_resource {
 	s64			bo_stats_total_allocated;
 
 	s64			bo_stats_peak_allocated;
+
+	s64			bo_stats_count_allocated;
 };
 
 /**
diff --git a/kernel/cgroup/drm.c b/kernel/cgroup/drm.c
index 0bf5b95668c4..85e46ece4a82 100644
--- a/kernel/cgroup/drm.c
+++ b/kernel/cgroup/drm.c
@@ -132,6 +132,9 @@ static void drmcg_print_stats(struct drmcg_device_resource *ddr,
 	case DRMCG_TYPE_BO_PEAK:
 		seq_printf(sf, "%lld\n", ddr->bo_stats_peak_allocated);
 		break;
+	case DRMCG_TYPE_BO_COUNT:
+		seq_printf(sf, "%lld\n", ddr->bo_stats_count_allocated);
+		break;
 	default:
 		seq_puts(sf, "\n");
 		break;
@@ -186,6 +189,12 @@ struct cftype files[] = {
 		.private = DRMCG_CTF_PRIV(DRMCG_TYPE_BO_PEAK,
 						DRMCG_FTYPE_STATS),
 	},
+	{
+		.name = "buffer.count.stats",
+		.seq_show = drmcg_seq_show,
+		.private = DRMCG_CTF_PRIV(DRMCG_TYPE_BO_COUNT,
+						DRMCG_FTYPE_STATS),
+	},
 	{ }	/* terminate */
 };
 
@@ -272,6 +281,8 @@ void drmcg_chg_bo_alloc(struct drmcg *drmcg, struct drm_device *dev,
 
 		if (ddr->bo_stats_peak_allocated < (s64)size)
 			ddr->bo_stats_peak_allocated = (s64)size;
+
+		ddr->bo_stats_count_allocated++;
 	}
 	mutex_unlock(&dev->drmcg_mutex);
 }
@@ -289,15 +300,20 @@ EXPORT_SYMBOL(drmcg_chg_bo_alloc);
 void drmcg_unchg_bo_alloc(struct drmcg *drmcg, struct drm_device *dev,
 		size_t size)
 {
+	struct drmcg_device_resource *ddr;
 	int devIdx = dev->primary->index;
 
 	if (drmcg == NULL)
 		return;
 
 	mutex_lock(&dev->drmcg_mutex);
-	for ( ; drmcg != NULL; drmcg = drmcg_parent(drmcg))
-		drmcg->dev_resources[devIdx]->bo_stats_total_allocated
-			-= (s64)size;
+	for ( ; drmcg != NULL; drmcg = drmcg_parent(drmcg)) {
+		ddr = drmcg->dev_resources[devIdx];
+
+		ddr->bo_stats_total_allocated -= (s64)size;
+
+		ddr->bo_stats_count_allocated--;
+	}
 	mutex_unlock(&dev->drmcg_mutex);
 }
 EXPORT_SYMBOL(drmcg_unchg_bo_alloc);
-- 
2.22.0