Re: [PATCH 3/3] drm/msm: Expose client engine utilization via fdinfo

Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx> · Mon, 28 Feb 2022 14:33:41 +0000

On 25/02/2022 22:14, Rob Clark wrote:
On Fri, Feb 25, 2022 at 12:25 PM Rob Clark <robdclark@xxxxxxxxx> wrote:

From: Rob Clark <robdclark@xxxxxxxxxxxx>

Similar to AMD commit
874442541133 ("drm/amdgpu: Add show_fdinfo() interface"), using the
infrastructure added in previous patches, we add basic client info
and GPU engine utilisation for msm.

Example output:

         # cat /proc/`pgrep glmark2`/fdinfo/6
         pos:    0
         flags:  02400002
         mnt_id: 21
         ino:    162
         drm-driver:     msm
         drm-client-id:  7
         drm-engine-gpu: 1734371319 ns
         drm-cycles-gpu: 1153645024

Nice, so my vendor agnostic actually worked (with that single fixup of 
accounting for the fact pdev tag is optional)?

Note that it might be useful to have a standardized way to report # of
cycles and max freq, so userspace tool can derive %utilization in
addition to just %busy

How do you define %utilisation vs %busy - I don't exactly follow since I 
see the two as same?

Looking at your patch I guess I don't understand the difference between 
'elapsed' and 'cycles' inside your retire_submit(). Both are scoped to a 
single context and are not global? If 'elapsed' is time context has 
spent on the GPU, cycles isn't the same just in a different unit?

Regards,

Tvrtko

BR,
-R


See also: https://patchwork.freedesktop.org/patch/468505/

Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
  drivers/gpu/drm/msm/msm_drv.c | 17 ++++++++++++++++-
  drivers/gpu/drm/msm/msm_gpu.c | 20 ++++++++++++++++++--
  drivers/gpu/drm/msm/msm_gpu.h | 19 +++++++++++++++++++
  3 files changed, 53 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 16f37f3d9061..fdf401e6f09e 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -911,7 +911,22 @@ static const struct drm_ioctl_desc msm_ioctls[] = {
         DRM_IOCTL_DEF_DRV(MSM_SUBMITQUEUE_QUERY, msm_ioctl_submitqueue_query, DRM_RENDER_ALLOW),
  };

-DEFINE_DRM_GEM_FOPS(fops);
+static void msm_fop_show_fdinfo(struct seq_file *m, struct file *f)
+{
+       struct drm_file *file = f->private_data;
+       struct drm_device *dev = file->minor->dev;
+       struct msm_drm_private *priv = dev->dev_private;
+       struct drm_printer p = drm_seq_file_printer(m);
+
+       if (!priv->gpu)
+               return;
+
+       msm_gpu_show_fdinfo(priv->gpu, file->driver_priv, &p);
+}
+
+DEFINE_DRM_GEM_FOPS(fops,
+       .show_fdinfo = msm_fop_show_fdinfo,
+);

  static const struct drm_driver msm_driver = {
         .driver_features    = DRIVER_GEM |
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index 173ebd449f2f..6302f3fe564b 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -4,6 +4,8 @@
   * Author: Rob Clark <robdclark@xxxxxxxxx>
   */

+#include "drm/drm_drv.h"
+
  #include "msm_gpu.h"
  #include "msm_gem.h"
  #include "msm_mmu.h"
@@ -146,6 +148,15 @@ int msm_gpu_pm_suspend(struct msm_gpu *gpu)
         return 0;
  }

+void msm_gpu_show_fdinfo(struct msm_gpu *gpu, struct msm_file_private *ctx,
+                        struct drm_printer *p)
+{
+       drm_printf(p, "drm-driver:\t%s\n", gpu->dev->driver->name);
+       drm_printf(p, "drm-client-id:\t%u\n", ctx->seqno);
+       drm_printf(p, "drm-engine-gpu:\t%llu ns\n", ctx->elapsed_ns);
+       drm_printf(p, "drm-cycles-gpu:\t%llu\n", ctx->cycles);
+}
+
  int msm_gpu_hw_init(struct msm_gpu *gpu)
  {
         int ret;
@@ -643,7 +654,7 @@ static void retire_submit(struct msm_gpu *gpu, struct msm_ringbuffer *ring,
  {
         int index = submit->seqno % MSM_GPU_SUBMIT_STATS_COUNT;
         volatile struct msm_gpu_submit_stats *stats;
-       u64 elapsed, clock = 0;
+       u64 elapsed, clock = 0, cycles;
         unsigned long flags;

         stats = &ring->memptrs->stats[index];
@@ -651,12 +662,17 @@ static void retire_submit(struct msm_gpu *gpu, struct msm_ringbuffer *ring,
         elapsed = (stats->alwayson_end - stats->alwayson_start) * 10000;
         do_div(elapsed, 192);

+       cycles = stats->cpcycles_end - stats->cpcycles_start;
+
         /* Calculate the clock frequency from the number of CP cycles */
         if (elapsed) {
-               clock = (stats->cpcycles_end - stats->cpcycles_start) * 1000;
+               clock = cycles * 1000;
                 do_div(clock, elapsed);
         }

+       submit->queue->ctx->elapsed_ns += elapsed;
+       submit->queue->ctx->cycles     += cycles;
+
         trace_msm_gpu_submit_retired(submit, elapsed, clock,
                 stats->alwayson_start, stats->alwayson_end);

diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index 696e2ed8a236..ad4fe05dee03 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -328,6 +328,22 @@ struct msm_file_private {
         struct kref ref;
         int seqno;

+       /**
+        * elapsed:
+        *
+        * The total (cumulative) elapsed time GPU was busy with rendering
+        * from this context in ns.
+        */
+       uint64_t elapsed_ns;
+
+       /**
+        * cycles:
+        *
+        * The total (cumulative) GPU cycles elapsed attributed to this
+        * context.
+        */
+       uint64_t cycles;
+
         /**
          * entities:
          *
@@ -511,6 +527,9 @@ static inline void gpu_write64(struct msm_gpu *gpu, u32 lo, u32 hi, u64 val)
  int msm_gpu_pm_suspend(struct msm_gpu *gpu);
  int msm_gpu_pm_resume(struct msm_gpu *gpu);

+void msm_gpu_show_fdinfo(struct msm_gpu *gpu, struct msm_file_private *ctx,
+                        struct drm_printer *p);
+
  int msm_submitqueue_init(struct drm_device *drm, struct msm_file_private *ctx);
  struct msm_gpu_submitqueue *msm_submitqueue_get(struct msm_file_private *ctx,
                 u32 id);
--
2.35.1







