OK
-----Original Message-----
From: Kuehling, Felix <Felix.Kuehling@xxxxxxx>
Sent: Tuesday, February 1, 2022 12:24 AM
To: Zhou1, Tao <Tao.Zhou1@xxxxxxx>; Chai, Thomas <YiPeng.Chai@xxxxxxx>; amd-gfx@xxxxxxxxxxxxxxxxxxxxx
Cc: Clements, John <John.Clements@xxxxxxx>; Zhang, Hawking <Hawking.Zhang@xxxxxxx>
Subject: Re: [PATCH 1/2] drm/amdgpu: Fixed the defect of soft lock caused by infinite loop
Am 2022-01-29 um 22:19 schrieb Zhou1, Tao:
> [AMD Official Use Only]
>
>
>
>> -----Original Message-----
>> From: Chai, Thomas <YiPeng.Chai@xxxxxxx>
>> Sent: Saturday, January 29, 2022 8:34 PM
>> To: amd-gfx@xxxxxxxxxxxxxxxxxxxxx
>> Cc: Chai, Thomas <YiPeng.Chai@xxxxxxx>; Zhang, Hawking
>> <Hawking.Zhang@xxxxxxx>; Zhou1, Tao <Tao.Zhou1@xxxxxxx>; Clements,
>> John <John.Clements@xxxxxxx>; Chai, Thomas <YiPeng.Chai@xxxxxxx>
>> Subject: [PATCH 1/2] drm/amdgpu: Fixed the defect of soft lock caused
>> by infinite loop
>>
>> 1. The infinite loop case only occurs on multiple cards support
>> ras functions.
>> 2. The explanation of root cause refer to 76641cbbf196523b5752c6cf68f86.
>> 3. Create new node to manage each unique ras instance to guarantee
>> each device .ras_list is completely independent.
>> 4. Fixes:7a6b8ab3231b511915cb94cac1debabf093.
>> 5. The soft locked logs are as follows:
>> [ 262.165690] CPU: 93 PID: 758 Comm: kworker/93:1 Tainted: G OE
>> 5.13.0-27-generic #29~20.04.1-Ubuntu
>> [ 262.165695] Hardware name: Supermicro AS -4124GS-TNR/H12DSG-O-CPU,
>> BIOS T20200717143848 07/17/2020 [ 262.165698] Workqueue: events
>> amdgpu_ras_do_recovery [amdgpu] [ 262.165980] RIP:
>> 0010:amdgpu_ras_get_ras_block+0x86/0xd0 [amdgpu] [ 262.166239] Code:
>> 68
>> d8 4c 8d 71 d8 48 39 c3 74 54 49 8b 45 38 48 85 c0 74 32 44 89 fa 44
>> 89 e6 4c 89 ef e8 82 e4 9b dc 85 c0 74 3c 49 8b 46 28 <49> 8d 56 28
>> 4d 89 f5 48 83 e8 28 48
>> 39 d3 74 25 49 89 c6 49 8b 45 [ 262.166243] RSP:
>> 0018:ffffac908fa87d80
>> EFLAGS: 00000202 [ 262.166247] RAX: ffffffffc1394248 RBX:
>> ffff91e4ab8d6e20
>> RCX: ffffffffc1394248 [ 262.166249] RDX: ffff91e4aa356e20 RSI:
>> 000000000000000e RDI: ffff91e4ab8c0000 [ 262.166252] RBP:
>> ffffac908fa87da8 R08: 0000000000000007 R09: 0000000000000001 [
>> 262.166254] R10: ffff91e4930b64ec R11: 0000000000000000 R12:
>> 000000000000000e [ 262.166256] R13: ffff91e4aa356df8 R14:
>> ffffffffc1394320
>> R15: 0000000000000003 [ 262.166258] FS: 0000000000000000(0000)
>> GS:ffff92238fb40000(0000) knlGS:0000000000000000 [ 262.166261] CS:
>> 0010
>> DS: 0000 ES: 0000 CR0: 0000000080050033 [ 262.166264] CR2:
>> 00000001004865d0 CR3: 000000406d796000 CR4: 0000000000350ee0 [
>> 262.166267] Call Trace:
>> [ 262.166272] amdgpu_ras_do_recovery+0x130/0x290 [amdgpu] [
>> 262.166529] ? psi_task_switch+0xd2/0x250 [ 262.166537] ?
>> __switch_to+0x11d/0x460 [ 262.166542] ? __switch_to_asm+0x36/0x70 [
>> 262.166549] process_one_work+0x220/0x3c0 [ 262.166556]
>> worker_thread+0x4d/0x3f0 [ 262.166560] ?
>> process_one_work+0x3c0/0x3c0 [ 262.166563] kthread+0x12b/0x150 [ 262.166568] ?
>> set_kthread_struct+0x40/0x40 [ 262.166571] ret_from_fork+0x22/0x30
>>
>> Signed-off-by: yipechai <YiPeng.Chai@xxxxxxx>
>> ---
>> drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c | 37
>> ++++++++++++++++++++++--
>> - drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h | 3 --
>> 2 files changed, 33 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
>> index 9d7c778c1a2d..b0aa67308c31 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.c
>> @@ -75,6 +75,13 @@ const char *ras_mca_block_string[] = {
>> "mca_iohc",
>> };
>>
>> +struct amdgpu_ras_block_list {
>> + /* ras block link */
>> + struct list_head node;
>> +
>> + struct amdgpu_ras_block_object *ras_obj; };
>> +
>> const char *get_ras_block_str(struct ras_common_if *ras_block) {
>> if (!ras_block)
>> @@ -880,7 +887,8 @@ static struct amdgpu_ras_block_object
>> *amdgpu_ras_get_ras_block(struct amdgpu_de
>> enum amdgpu_ras_block block,
>> uint32_t sub_block_index) {
>> int loop_cnt = 0;
>> - struct amdgpu_ras_block_object *obj, *tmp;
>> + struct amdgpu_ras_block_list *node, *tmp;
>> + struct amdgpu_ras_block_object *obj;
>>
>> if (block >= AMDGPU_RAS_BLOCK__LAST)
>> return NULL;
>> @@ -888,7 +896,13 @@ static struct amdgpu_ras_block_object
>> *amdgpu_ras_get_ras_block(struct amdgpu_de
>> if (!amdgpu_ras_is_supported(adev, block))
>> return NULL;
>>
>> - list_for_each_entry_safe(obj, tmp, &adev->ras_list, node) {
>> + list_for_each_entry_safe(node, tmp, &adev->ras_list, node) {
>> + if (!node->ras_obj) {
>> + DRM_ERROR("Warning: abnormal ras list node");
> [Tao]: dev_warn is recommended.
>
>> + continue;
>> + }
>> +
>> + obj = node->ras_obj;
>> if (obj->ras_block_match) {
>> if (obj->ras_block_match(obj, block, sub_block_index) == 0)
>> return obj;
>> @@ -2527,6 +2541,7 @@ int amdgpu_ras_pre_fini(struct amdgpu_device
>> *adev)
>>
>> int amdgpu_ras_fini(struct amdgpu_device *adev) {
>> + struct amdgpu_ras_block_list *ras_node, *tmp;
>> struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
>>
>> if (!adev->ras_enabled || !con)
>> @@ -2545,6 +2560,12 @@ int amdgpu_ras_fini(struct amdgpu_device *adev)
>> amdgpu_ras_set_context(adev, NULL);
>> kfree(con);
>>
>> + /* Clear ras blocks from ras_list and free ras block list node */
>> + list_for_each_entry_safe(ras_node, tmp, &adev->ras_list, node) {
>> + list_del(&ras_node->node);
>> + kfree(ras_node);
>> + }
>> +
>> return 0;
>> }
>>
>> @@ -2754,14 +2775,22 @@ int amdgpu_ras_reset_gpu(struct amdgpu_device
>> *adev) int amdgpu_ras_register_ras_block(struct amdgpu_device *adev,
>> struct amdgpu_ras_block_object *ras_block_obj) {
>> + struct amdgpu_ras_block_list *ras_node;
>> if (!adev || !ras_block_obj)
>> return -EINVAL;
>>
>> if (!amdgpu_ras_asic_supported(adev))
>> return 0;
>>
>> - INIT_LIST_HEAD(&ras_block_obj->node);
>> - list_add_tail(&ras_block_obj->node, &adev->ras_list);
>> + ras_node = kzalloc(sizeof(*ras_node), GFP_KERNEL);
>> + if (!ras_node) {
>> + DRM_ERROR("Failed to allocate ras_node");
> [Tao] dev_err is better.
You should not print error messages after failed memory allocation.
Out-of-memory errors already produce noisy log messages of their own.
checkpatch.pl warns about such redundant error messages with "Possible unnecessary 'out of memory' message".
Regards,
Felix
>
>> + return -EINVAL;
> [Tao]: how about return -ENOMEM here?
>
>> + }
>> +
>> + INIT_LIST_HEAD(&ras_node->node);
>> + ras_node->ras_obj = ras_block_obj;
>> + list_add_tail(&ras_node->node, &adev->ras_list);
>>
>> return 0;
>> }
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
>> index a51a281bd91a..a55743b12d57 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras.h
>> @@ -493,9 +493,6 @@ struct amdgpu_ras_block_object {
>>
>> uint32_t sub_block_index;
>>
>> - /* ras block link */
>> - struct list_head node;
>> -
>> int (*ras_block_match)(struct amdgpu_ras_block_object *block_obj,
>> enum amdgpu_ras_block block, uint32_t sub_block_index);
>> int (*ras_late_init)(struct amdgpu_device *adev, void *ras_info);
>> --
>> 2.25.1
