On Fri, Mar 1, 2024 at 10:54 AM Rob Clark <robdclark@xxxxxxxxx> wrote:
From: Rob Clark <robdclark@xxxxxxxxxxxx>
Perfetto can use these traces to track global and per-process GPU memory
usage.
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
I realized the tracepoint that perfetto uses to show GPU memory usage
globally and per-process was already upstream, but with no users.
This overlaps a bit with fdinfo, but ftrace is a lighter weight
mechanism and fits better with perfetto (plus is already supported in
trace_processor and perfetto UI, whereas something fdinfo based would
require new code to be added in perfetto.
We could probably do this more globally (ie. drm_gem_get/put_pages() and
drm_gem_handle_create_tail()/drm_gem_object_release_handle() if folks
prefer. Not sure where that leaves the TTM drivers.
drivers/gpu/drm/msm/Kconfig | 1 +
drivers/gpu/drm/msm/msm_drv.h | 5 +++++
drivers/gpu/drm/msm/msm_gem.c | 37 +++++++++++++++++++++++++++++++++++
drivers/gpu/drm/msm/msm_gpu.h | 8 ++++++++
4 files changed, 51 insertions(+)
diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
index f202f26adab2..e4c912fcaf22 100644
--- a/drivers/gpu/drm/msm/Kconfig
+++ b/drivers/gpu/drm/msm/Kconfig
@@ -33,6 +33,7 @@ config DRM_MSM
select PM_OPP
select NVMEM
select PM_GENERIC_DOMAINS
+ select TRACE_GPU_MEM
help
DRM/KMS driver for MSM/snapdragon.
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index 16a7cbc0b7dd..cb8f7e804b5b 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -137,6 +137,11 @@ struct msm_drm_private {
struct msm_rd_state *hangrd; /* debugfs to dump hanging submits */
struct msm_perf_state *perf;
+ /**
+ * total_mem: Total/global amount of memory backing GEM objects.
+ */
+ atomic64_t total_mem;
+
/**
* List of all GEM objects (mainly for debugfs, protected by obj_lock
* (acquire before per GEM object lock)
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 175ee4ab8a6f..e04c4af5d154 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -12,6 +12,9 @@
#include <linux/pfn_t.h>
#include <drm/drm_prime.h>
+#include <drm/drm_file.h>
+
+#include <trace/events/gpu_mem.h>
#include "msm_drv.h"
#include "msm_fence.h"
@@ -33,6 +36,34 @@ static bool use_pages(struct drm_gem_object *obj)
return !msm_obj->vram_node;
}
+static void update_device_mem(struct msm_drm_private *priv, ssize_t size)
+{
+ uint64_t total_mem = atomic64_add_return(size, &priv->total_mem);
+ trace_gpu_mem_total(0, 0, total_mem);
+}
+
+static void update_ctx_mem(struct drm_file *file, ssize_t size)
+{
+ struct msm_file_private *ctx = file->driver_priv;
+ uint64_t ctx_mem = atomic64_add_return(size, &ctx->ctx_mem);
+
+ rcu_read_lock(); /* Locks file->pid! */
+ trace_gpu_mem_total(0, pid_nr(file->pid), ctx_mem);
+ rcu_read_unlock();
+
+}
+
+static int msm_gem_open(struct drm_gem_object *obj, struct drm_file *file)
+{
+ update_ctx_mem(file, obj->size);
+ return 0;
+}
+
+static void msm_gem_close(struct drm_gem_object *obj, struct drm_file *file)
+{
+ update_ctx_mem(file, -obj->size);
+}
+
/*
* Cache sync.. this is a bit over-complicated, to fit dma-mapping
* API. Really GPU cache is out of scope here (handled on cmdstream)
@@ -156,6 +187,8 @@ static struct page **get_pages(struct drm_gem_object *obj)
return p;
}
+ update_device_mem(dev->dev_private, obj->size);
+
msm_obj->pages = p;
msm_obj->sgt = drm_prime_pages_to_sg(obj->dev, p, npages);
@@ -209,6 +242,8 @@ static void put_pages(struct drm_gem_object *obj)
msm_obj->sgt = NULL;
}
+ update_device_mem(obj->dev->dev_private, -obj->size);
+
if (use_pages(obj))
drm_gem_put_pages(obj, msm_obj->pages, true, false);
else
@@ -1118,6 +1153,8 @@ static const struct vm_operations_struct vm_ops = {
static const struct drm_gem_object_funcs msm_gem_object_funcs = {
.free = msm_gem_free_object,
+ .open = msm_gem_open,
+ .close = msm_gem_close,
.pin = msm_gem_prime_pin,
.unpin = msm_gem_prime_unpin,
.get_sg_table = msm_gem_prime_get_sg_table,
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index 2bfcb222e353..f7d2a7d6f8cc 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -428,6 +428,14 @@ struct msm_file_private {
* level.
*/
struct drm_sched_entity *entities[NR_SCHED_PRIORITIES * MSM_GPU_MAX_RINGS];
+
+ /**
+ * ctx_mem:
+ *
+ * Total amount of memory of GEM buffers with handles attached for
+ * this context.
+ */
+ atomic64_t ctx_mem;
};
Just for added context, past discussions on TRACE_GPU_MEM:
Some have even suggested deleting the tracepoint altogether.
Personally, I think we should land an internal user in a non-breaking way, since userspace (Perfetto) already depends on it. Right now, we're in limbo for multiple years ...
/**
--
2.44.0
