[PATCH v1 2/2] drm/amdgpu: adding device coredump support
Sharma, Shashank
shashank.sharma at amd.com
Tue May 24 12:50:23 UTC 2022
On 5/24/2022 2:10 PM, Somalapuram, Amaranath wrote:
>
> On 5/24/2022 3:23 PM, Sharma, Shashank wrote:
>>
>>
>> On 5/24/2022 8:42 AM, Somalapuram, Amaranath wrote:
>>>
>>> On 5/20/2022 7:52 PM, Sharma, Shashank wrote:
>>>>
>>>>
>>>> On 5/20/2022 3:49 PM, Somalapuram Amaranath wrote:
>>>>> Added device coredump information:
>>>>> - Kernel version
>>>>> - Module
>>>>> - Time
>>>>> - VRAM status
>>>>> - Guilty process name and PID
>>>>> - GPU register dumps
>>>>>
>>>>> Signed-off-by: Somalapuram Amaranath <Amaranath.Somalapuram at amd.com>
>>>>> ---
>>>>> drivers/gpu/drm/amd/amdgpu/amdgpu.h | 3 ++
>>>>> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 59
>>>>> ++++++++++++++++++++++
>>>>> 2 files changed, 62 insertions(+)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>>> index c79d9992b113..f28d9c563f74 100644
>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>>>>> @@ -1044,6 +1044,9 @@ struct amdgpu_device {
>>>>> uint32_t *reset_dump_reg_list;
>>>>> uint32_t *reset_dump_reg_value;
>>>>> int num_regs;
>>>>> + struct amdgpu_task_info reset_context_task_info;
>>>>> + bool reset_context_vram_lost;
>>>>
>>>> How about drop the 'context' from name and just reset_task_info and
>>>> reset_vram_lost ?
>>> OK.
>>>>
>>>>> + struct timespec64 reset_time;
>>>>> struct amdgpu_reset_domain *reset_domain;
>>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>> index 963c897a76e6..f9b710e741a7 100644
>>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>>> @@ -32,6 +32,8 @@
>>>>> #include <linux/slab.h>
>>>>> #include <linux/iommu.h>
>>>>> #include <linux/pci.h>
>>>>> +#include <linux/devcoredump.h>
>>>>> +#include <generated/utsrelease.h>
>>>>> #include <drm/drm_atomic_helper.h>
>>>>> #include <drm/drm_probe_helper.h>
>>>>> @@ -4733,6 +4735,55 @@ static int amdgpu_reset_reg_dumps(struct
>>>>> amdgpu_device *adev)
>>>>> return 0;
>>>>> }
>>>>> +#ifdef CONFIG_DEV_COREDUMP
>>>>> +static ssize_t amdgpu_devcoredump_read(char *buffer, loff_t offset,
>>>>> + size_t count, void *data, size_t datalen)
>>>>> +{
>>>>> + struct drm_printer p;
>>>>> + struct amdgpu_device *adev = data;
>>>>> + struct drm_print_iterator iter;
>>>>> + int i;
>>>>> +
>>>>
>>>> A NULL check for 'buffer' here could prevent a segfault later.
>>>>
>>> Agreed.
>>>>> + iter.data = buffer;
>>>>> + iter.offset = 0;
>>>>> + iter.start = offset;
>>>>> + iter.remain = count;
>>>>> +
>>>>> + p = drm_coredump_printer(&iter);
>>>>> +
>>>>> + drm_printf(&p, "**** AMDGPU Device Coredump ****\n");
>>>>> + drm_printf(&p, "kernel: " UTS_RELEASE "\n");
>>>>> + drm_printf(&p, "module: " KBUILD_MODNAME "\n");
>>>>> + drm_printf(&p, "time: %lld.%09ld\n", adev->reset_time.tv_sec,
>>>>> adev->reset_time.tv_nsec);
>>>>> + if (adev->reset_context_task_info.pid)
>>>>> + drm_printf(&p, "process_name: %s PID: %d\n",
>>>>> + adev->reset_context_task_info.process_name,
>>>>> + adev->reset_context_task_info.pid);
>>>> Please fix the alignment of print variables.
>>>>
>>> I will cross check this.
>>>>> +
>>>>> + if (adev->reset_context_vram_lost)
>>>>> + drm_printf(&p, "VRAM is lost due to GPU reset!\n");
>>>>> + if (adev->num_regs) {
>>>>> + drm_printf(&p, "AMDGPU register dumps:\nOffset: Value:\n");
>>>>> +
>>>>> + for (i = 0; i < adev->num_regs; i++)
>>>>> + drm_printf(&p, "0x%08x: 0x%08x\n",
>>>>> + adev->reset_dump_reg_list[i],
>>>>> + adev->reset_dump_reg_value[i]);
>>>>> + }
>>>>> +
>>>>> + return count - iter.remain;
>>>>> +}
>>>>> +
>>>>> +static void amdgpu_reset_capture_coredumpm(struct amdgpu_device
>>>>> *adev)
>>>>> +{
>>>>> + struct drm_device *dev = adev_to_drm(adev);
>>>>> +
>>>>> + ktime_get_ts64(&adev->reset_time);
>>>>> + dev_coredumpm(dev->dev, THIS_MODULE, adev, 0, GFP_KERNEL,
>>>>> + amdgpu_devcoredump_read, NULL);
>>>> instead of registering NULL as free function, I would prefer you to
>>>> have a dummy no_op free function registered, which we can consume if
>>>> something changes.
>>> you mean something like this (function without any code):
>>> staticvoidamdgpu_devcoredump_free(void*data)
>>> {
>>> }
>>
>> Yes, precisely.
>>
>>>>> +}
>>>>> +#endif
>>>>> +
>>>>> int amdgpu_do_asic_reset(struct list_head *device_list_handle,
>>>>> struct amdgpu_reset_context *reset_context)
>>>>> {
>>>>> @@ -4817,6 +4868,14 @@ int amdgpu_do_asic_reset(struct list_head
>>>>> *device_list_handle,
>>>>> goto out;
>>>>> vram_lost =
>>>>> amdgpu_device_check_vram_lost(tmp_adev);
>>>>> +#ifdef CONFIG_DEV_COREDUMP
>>>>> + tmp_adev->reset_context_vram_lost = vram_lost;
>>>>> + tmp_adev->reset_context_task_info.pid = 0;
>>>> why is the PID hardcoded to 0 ?
>>> in case of reset context reset_context->job->vm is null (possibility
>>> that reset can be non VM related).
>>> If we don't set tmp_adev->reset_context_task_info.pid = 0, it will
>>> show previous reset valid PID.
>>>
>>
>> But when the VM is not NULL, are we updating this PID somewhere ? I
>> did not see that happening in this series.
> This is the only place where PID get updated.
> For example sequence of operation like:
> 1st reset:
> -valid VM and tmp_adev->reset_context_task_info.pid is set to some valid
> PID
> 2nd reset:
> -invalid VM
> -tmp_adev context will remain same (adev context will be same after
> successful GPU reset sequence).
> -tmp_adev->reset_context_task_info.pid will be holding 1st reset PID value
>
> if we don't set it 0, it can give wrong PID.
>
I get your point, and agree, that when the vm is invalid, PID is invalid
so we should send pid=0. But where are you handling the case when VM is
valid and pid is valid ?
- Shashank
> Regards,
> S.Amarnath
>>
>> - Shashank
>>
>>>
>>> Regards,
>>> S.Amarnath
>>>>> + if (reset_context->job && reset_context->job->vm)
>>>>> + tmp_adev->reset_context_task_info =
>>>>> + reset_context->job->vm->task_info;
>>>>> + amdgpu_reset_capture_coredumpm(tmp_adev);
>>>>> +#endif
>>>>> if (vram_lost) {
>>>>> DRM_INFO("VRAM is lost due to GPU reset!\n");
>>>>>
>>>> - Shashank
>>>> amdgpu_inc_vram_lost(tmp_adev);
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