[PATCH 2/2] drm/amdgpu: add amdgpu runpm usage trace for separate funcs

[Deucher, Alexander]

[Public]

> -----Original Message-----
> From: Liang, Prike <Prike.Liang at amd.com>
> Sent: Thursday, November 9, 2023 2:37 AM
> To: amd-gfx at lists.freedesktop.org
> Cc: Deucher, Alexander <Alexander.Deucher at amd.com>; Liang, Prike
> <Prike.Liang at amd.com>
> Subject: [PATCH 2/2] drm/amdgpu: add amdgpu runpm usage trace for
> separate funcs
>
> Add trace for amdgpu runpm separate funcs usage and this will help
> debugging on the case of runpm usage missed to dereference.
> In the normal case the runpm usage count referred by one kind of
> functionality pairwise and usage should be changed from 1 to 0, otherwise
> there will be an issue in the amdgpu runpm usage dereference.
>
> Signed-off-by: Prike Liang <Prike.Liang at amd.com>

Looks good.  Not sure if you want to add tracepoints to the other call sites as well.  These are probably the trickiest however.

Acked-by: Alex Deucher <alexander.deucher at amd.com>

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c |  4 ++++
>  drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c   |  7 ++++++-
>  drivers/gpu/drm/amd/amdgpu/amdgpu_trace.h   | 15 +++++++++++++++
>  3 files changed, 25 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> index e7e87a3b2601..decbbe3d4f06 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> @@ -42,6 +42,7 @@
>  #include <linux/dma-fence-array.h>
>  #include <linux/pci-p2pdma.h>
>  #include <linux/pm_runtime.h>
> +#include "amdgpu_trace.h"
>
>  /**
>   * amdgpu_dma_buf_attach - &dma_buf_ops.attach implementation @@ -
> 63,6 +64,7 @@ static int amdgpu_dma_buf_attach(struct dma_buf *dmabuf,
>               attach->peer2peer = false;
>
>       r = pm_runtime_get_sync(adev_to_drm(adev)->dev);
> +     trace_amdgpu_runpm_reference_dumps(1, __func__);
>       if (r < 0)
>               goto out;
>
> @@ -70,6 +72,7 @@ static int amdgpu_dma_buf_attach(struct dma_buf
> *dmabuf,
>
>  out:
>       pm_runtime_put_autosuspend(adev_to_drm(adev)->dev);
> +     trace_amdgpu_runpm_reference_dumps(0, __func__);
>       return r;
>  }
>
> @@ -90,6 +93,7 @@ static void amdgpu_dma_buf_detach(struct dma_buf
> *dmabuf,
>
>       pm_runtime_mark_last_busy(adev_to_drm(adev)->dev);
>       pm_runtime_put_autosuspend(adev_to_drm(adev)->dev);
> +     trace_amdgpu_runpm_reference_dumps(0, __func__);
>  }
>
>  /**
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> index 709a2c1b9d63..1026a9fa0c0f 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> @@ -183,6 +183,7 @@ int amdgpu_fence_emit(struct amdgpu_ring *ring,
> struct dma_fence **f, struct amd
>       amdgpu_ring_emit_fence(ring, ring->fence_drv.gpu_addr,
>                              seq, flags | AMDGPU_FENCE_FLAG_INT);
>       pm_runtime_get_noresume(adev_to_drm(adev)->dev);
> +     trace_amdgpu_runpm_reference_dumps(1, __func__);
>       ptr = &ring->fence_drv.fences[seq & ring-
> >fence_drv.num_fences_mask];
>       if (unlikely(rcu_dereference_protected(*ptr, 1))) {
>               struct dma_fence *old;
> @@ -286,8 +287,11 @@ bool amdgpu_fence_process(struct amdgpu_ring
> *ring)
>           seq != ring->fence_drv.sync_seq)
>               amdgpu_fence_schedule_fallback(ring);
>
> -     if (unlikely(seq == last_seq))
> +     if (unlikely(seq == last_seq)) {
> +             pm_runtime_put_autosuspend(adev_to_drm(adev)->dev);
> +             trace_amdgpu_runpm_reference_dumps(0, __func__);
>               return false;
> +     }
>
>       last_seq &= drv->num_fences_mask;
>       seq &= drv->num_fences_mask;
> @@ -310,6 +314,7 @@ bool amdgpu_fence_process(struct amdgpu_ring
> *ring)
>               dma_fence_put(fence);
>               pm_runtime_mark_last_busy(adev_to_drm(adev)->dev);
>               pm_runtime_put_autosuspend(adev_to_drm(adev)->dev);
> +             trace_amdgpu_runpm_reference_dumps(0, __func__);
>       } while (last_seq != seq);
>
>       return true;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_trace.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_trace.h
> index 2fd1bfb35916..5d4792645540 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_trace.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_trace.h
> @@ -554,6 +554,21 @@ TRACE_EVENT(amdgpu_reset_reg_dumps,
>                     __entry->value)
>  );
>
> +TRACE_EVENT(amdgpu_runpm_reference_dumps,
> +         TP_PROTO(uint32_t index, const char *func),
> +         TP_ARGS(index, func),
> +         TP_STRUCT__entry(
> +                          __field(uint32_t, index)
> +                          __string(func, func)
> +                          ),
> +         TP_fast_assign(
> +                        __entry->index = index;
> +                        __assign_str(func, func);
> +                        ),
> +         TP_printk("amdgpu runpm reference dump 0x%d: 0x%s\n",
> +                   __entry->index,
> +                   __get_str(func))
> +);
>  #undef AMDGPU_JOB_GET_TIMELINE_NAME
>  #endif
>
> --
> 2.34.1