Re: [PATCH v4 2/4] drm/amdgpu: Rework coredump to use memory dynamically

From: Shashank Sharma
Date: Thu Aug 17 2023 - 11:43:42 EST



On 17/08/2023 17:38, André Almeida wrote:


Em 17/08/2023 12:26, Shashank Sharma escreveu:

On 17/08/2023 17:17, André Almeida wrote:


Em 17/08/2023 12:04, Shashank Sharma escreveu:

On 17/08/2023 15:45, André Almeida wrote:
Hi Shashank,

Em 17/08/2023 03:41, Shashank Sharma escreveu:
Hello Andre,

On 15/08/2023 21:50, André Almeida wrote:
Instead of storing coredump information inside amdgpu_device struct,
move if to a proper separated struct and allocate it dynamically. This
will make it easier to further expand the logged information.

Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
---
v4: change kmalloc to kzalloc
---
  drivers/gpu/drm/amd/amdgpu/amdgpu.h        | 14 +++--
  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 63 ++++++++++++++--------
  2 files changed, 49 insertions(+), 28 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 9c6a332261ab..0d560b713948 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1088,11 +1088,6 @@ struct amdgpu_device {
      uint32_t *reset_dump_reg_list;
      uint32_t            *reset_dump_reg_value;
      int                             num_regs;
-#ifdef CONFIG_DEV_COREDUMP
-    struct amdgpu_task_info         reset_task_info;
-    bool                            reset_vram_lost;
-    struct timespec64               reset_time;
-#endif
      bool                            scpm_enabled;
      uint32_t                        scpm_status;
@@ -1105,6 +1100,15 @@ struct amdgpu_device {
      uint32_t            aid_mask;
  };
+#ifdef CONFIG_DEV_COREDUMP
+struct amdgpu_coredump_info {
+    struct amdgpu_device        *adev;
+    struct amdgpu_task_info         reset_task_info;
+    struct timespec64               reset_time;
+    bool                            reset_vram_lost;
+};

The patch looks good to me in general, but I would recommend slightly different arrangement and segregation of GPU reset information.

Please consider a higher level structure adev->gpu_reset_info, and move everything related to reset dump info into that, including this new coredump_info structure, something like this:

struct amdgpu_reset_info {

     uint32_t *reset_dump_reg_list;

     uint32_t *reset_dump_reg_value;

     int num_regs;


Right, I can encapsulate there reset_dump members,

#ifdef CONFIG_DEV_COREDUMP

    struct amdgpu_coredump_info *coredump_info;/* keep this dynamic allocation */

but we don't need a pointer for amdgpu_coredump_info inside amdgpu_device or inside of amdgpu_device->gpu_reset_info, right?

I think it would be better if we keep all of the GPU reset related data in the same structure, so adev->gpu_reset_info->coredump_info sounds about right to me.


But after patch 2/4, we don't need to store a coredump_info pointer inside adev, this is what I meant. What would be the purpose of having this pointer? It's freed by amdgpu_devcoredump_free(), so we don't need to keep track of it.

Well, actually we are pulling in some 0parallel efforts on enhancing the GPU reset information, and we were planning to use the coredump info for some additional things. So if I have the coredump_info available (like reset_task_info and vram_lost) across a few functions in the driver with adev, it would make my job easy there :).

It seems dangerous to use an object with this limited lifetime to rely to read on. If you want to use it you will need to change amdgpu_devcoredump_free() to drop a reference or you will need to use it statically, which defeats the purpose of this patch. Anyway, I'll add it as you requested.

I guess if the coredump_free function can make the

adev->reset_info->coredump_info= NULL, after freeing it, that will actually help the case.


While consuming it, I can simply check if (adev->reset_info->coredump_info) is available to be read.

- Shashank


- Shashank


- Shashank



#endif

}


This will make sure that all the relevant information is at the same place.

- Shashank

       amdgpu_inc_vram_lost(tmp_adev);