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

[Lazar, Lijo]

On 2/14/2023 7:56 AM, Zhou1, Tao wrote:


-----Original Message-----
From: Lazar, Lijo <lijo.la...@amd.com>
Sent: Monday, February 13, 2023 8:38 PM
To: Zhou1, Tao <tao.zh...@amd.com>; amd-gfx@lists.freedesktop.org; Zhang,
Hawking <hawking.zh...@amd.com>; Yang, Stanley
<stanley.y...@amd.com>; Chai, Thomas <yipeng.c...@amd.com>; Li, Candice
<candice...@amd.com>
Subject: Re: [PATCH] drm/amdgpu: don't increase UMC RAS UE count if no new
bad page



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

[Tao] amdgpu_ras_check_bad_page is already called in amdgpu_ras_add_bad_pages, 
this patch just makes use of the result of amdgpu_ras_check_bad_page.


In the patch, below two are called after error count is set to 0.
        amdgpu_ras_save_bad_pages
        amdgpu_dpm_send_hbm_bad_pages_num

Instead of that, just check if it's an existing badpage which is 
repeatedly accessed and proceed directly to the next step (reset if 
specified)

        if (amdgpu_ras_check_bad_page(adev, address))
                set error count to 0;
                goto reset_logic;

Thanks,
Lijo


Signed-off-by: Tao Zhou <tao.zh...@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);