Re: [PATCH] drm/amdgpu: don't increase UMC RAS UE count if no new bad page

["Lazar, Lijo" <lijo.lazar@amd.com>]

On 2/10/2023 2:15 PM, Tao Zhou wrote:
> If a UMC bad page is reserved but not freed by an application, the
> application may trigger uncorrectable error repeatly by accessing the page.
> 

There is amdgpu_ras_check_bad_page which checks if address is already 
part of an existing bad page. Can't that be used?

Thanks,
Lijo

> Signed-off-by: Tao Zhou <tao.zhou1@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 9 ++++++++-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_umc.c | 6 +++++-
>   2 files changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
> index e85c4689ce2c..eafe01a24349 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
> @@ -2049,7 +2049,7 @@ int amdgpu_ras_add_bad_pages(struct amdgpu_device *adev,
>   {
>   	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
>   	struct ras_err_handler_data *data;
> -	int ret = 0;
> +	int ret = 0, old_cnt;
>   	uint32_t i;
>   
>   	if (!con || !con->eh_data || !bps || pages <= 0)
> @@ -2060,6 +2060,8 @@ int amdgpu_ras_add_bad_pages(struct amdgpu_device *adev,
>   	if (!data)
>   		goto out;
>   
> +	old_cnt = data->count;
> +
>   	for (i = 0; i < pages; i++) {
>   		if (amdgpu_ras_check_bad_page_unlock(con,
>   			bps[i].retired_page << AMDGPU_GPU_PAGE_SHIFT))
> @@ -2079,6 +2081,11 @@ int amdgpu_ras_add_bad_pages(struct amdgpu_device *adev,
>   		data->count++;
>   		data->space_left--;
>   	}
> +
> +	/* all pages have been reserved before, no new bad page */
> +	if (old_cnt == data->count)
> +		ret = -EEXIST;
> +
>   out:
>   	mutex_unlock(&con->recovery_lock);
>   
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_umc.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_umc.c
> index 1c7fcb4f2380..772c431e4065 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_umc.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_umc.c
> @@ -145,8 +145,12 @@ static int amdgpu_umc_do_page_retirement(struct amdgpu_device *adev,
>   
>   		if ((amdgpu_bad_page_threshold != 0) &&
>   			err_data->err_addr_cnt) {
> -			amdgpu_ras_add_bad_pages(adev, err_data->err_addr,
> +			ret = amdgpu_ras_add_bad_pages(adev, err_data->err_addr,
>   						err_data->err_addr_cnt);
> +			/* if no new bad page is found, no need to increase ue count */
> +			if (ret == -EEXIST)
> +				err_data->ue_count = 0;
> +
>   			amdgpu_ras_save_bad_pages(adev);
>   
>   			amdgpu_dpm_send_hbm_bad_pages_num(adev, con->eeprom_control.ras_num_recs);