[PATCH v4 2/2] drm/xe/bo: add GPU memory trace points

[Lucas De Marchi]

On Thu, Jun 12, 2025 at 05:46:52PM +0100, Tvrtko Ursulin wrote:
>
>On 12/06/2025 06:40, Lucas De Marchi wrote:
>>On Wed, Jun 11, 2025 at 03:51:24PM -0700, Juston Li wrote:
>>>Add TRACE_GPU_MEM tracepoints for tracking global and per-process GPU
>>>memory usage.
>>>
>>>These are required by VSR on Android 12+ for reporting GPU driver memory
>>>allocations.
>>>
>>>v3:
>>>- Use now configurable CONFIG_TRACE_GPU_MEM instead of adding a
>>>  per-driver Kconfig (Lucas)
>>>
>>>v2:
>>>- Use u64 as preferred by checkpatch (Tvrtko)
>>>- Fix errors in comments/Kconfig description (Tvrtko)
>>>- drop redundant "CONFIG" in Kconfig
>>>
>>>Signed-off-by: Juston Li <justonli at chromium.org>
>>>Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
>>>---
>>>drivers/gpu/drm/xe/xe_bo.c           | 47 ++++++++++++++++++++++++++++
>>>drivers/gpu/drm/xe/xe_device_types.h | 16 ++++++++++
>>>2 files changed, 63 insertions(+)
>>>
>>>diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
>>>index 4e39188a021ab..89a3d23e3b800 100644
>>>--- a/drivers/gpu/drm/xe/xe_bo.c
>>>+++ b/drivers/gpu/drm/xe/xe_bo.c
>>>@@ -19,6 +19,8 @@
>>>
>>>#include <kunit/static_stub.h>
>>>
>>>+#include <trace/events/gpu_mem.h>
>>>+
>>>#include "xe_device.h"
>>>#include "xe_dma_buf.h"
>>>#include "xe_drm_client.h"
>>>@@ -418,6 +420,35 @@ static void xe_ttm_tt_account_subtract(struct 
>>>xe_device *xe, struct ttm_tt *tt)
>>>        xe_shrinker_mod_pages(xe->mem.shrinker, -(long)tt->num_pages, 0);
>>>}
>>>
>>>+#if IS_ENABLED(CONFIG_TRACE_GPU_MEM)
>>>+static void update_global_total_pages(struct ttm_device *ttm_dev, 
>>>long num_pages)
>>>+{
>>>+    struct xe_device *xe = ttm_to_xe_device(ttm_dev);
>>>+    u64 global_total_pages =
>>>+        atomic64_add_return(num_pages, &xe->global_total_pages);
>>>+
>>>+    trace_gpu_mem_total(0, 0, global_total_pages << PAGE_SHIFT);
>>>+}
>>>+
>>>+static void update_process_mem(struct drm_file *file, ssize_t size)
>>>+{
>>>+    struct xe_file *xef = to_xe_file(file);
>>>+    u64 process_mem = atomic64_add_return(size, &xef->process_mem);
>>>+
>>>+    rcu_read_lock(); /* Locks file->pid! */
>>>+    trace_gpu_mem_total(0, pid_nr(rcu_dereference(file->pid)), 
>>>process_mem);
>>
>>Isn't the first arg supposed to be the gpu id? Doesn't this become
>>invalid when I have e.g. LNL + BMG and the trace is enabled?
>
>Good point.
>
>u32 gpu_id does not seem possible to map to anything useful.

maybe minor_id? although I'm not sure if the intention is to share this
outside drm as seems the case.

>
>Shall we replace it with a string obtained from dev_name(struct device 
>*) ? As only Android parses them I think we can get still away with 
>changing the tracepoints ABI.

works for me too. Is Android actually parsing it or just ignoring?
Because afaics it's always 0 in msm.

Lucas De Marchi