Re: [PATCH v3 1/8] trace: ras: add ARM processor error information trace event

[Xie XiuQi]

Hi Tyler,

On 2017/4/18 1:18, Baicar, Tyler wrote:
> On 4/16/2017 9:16 PM, Xie XiuQi wrote:
>> On 2017/4/17 11:08, Xie XiuQi wrote:
>>>> On 3/30/2017 4:31 AM, Xie XiuQi wrote:
>>>>> Add a new trace event for ARM processor error information, so that
>>>>> the user will know what error occurred. With this information the
>>>>> user may take appropriate action.
>>>>>
>>>>> These trace events are consistent with the ARM processor error
>>>>> information table which defined in UEFI 2.6 spec section N.2.4.4.1.
>>>>>
>>>>> ---
>>>>> v2: add trace enabled condition as Steven's suggestion.
>>>>>       fix a typo.
>>>>> ---
>>>>>
>>>>> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
>>>>> Cc: Tyler Baicar <tbaicar@xxxxxxxxxxxxxx>
>>>>> Signed-off-by: Xie XiuQi <xiexiuqi@xxxxxxxxxx>
>>>>> ---
>>>>
> ...
>>>>> +/*
>>>>> + * First define the enums in MM_ACTION_RESULT to be exported to userspace
>>>>> + * via TRACE_DEFINE_ENUM().
>>>>> + */
>>>>> +#undef EM
>>>>> +#undef EMe
>>>>> +#define EM(a, b) TRACE_DEFINE_ENUM(a);
>>>>> +#define EMe(a, b)    TRACE_DEFINE_ENUM(a);
>>>>> +
>>>>> +ARM_PROC_ERR_TYPE
>>>>> +ARM_PROC_ERR_FLAGS
>>>> Are the above two lines supposed to be here?
>>>>> +
>>>>> +/*
>>>>> + * Now redefine the EM() and EMe() macros to map the enums to the strings
>>>>> + * that will be printed in the output.
>>>>> + */
>>>>> +#undef EM
>>>>> +#undef EMe
>>>>> +#define EM(a, b)        { a, b },
>>>>> +#define EMe(a, b)    { a, b }
>>>>> +
>>>>> +TRACE_EVENT(arm_proc_err,
>>>> I think it would be better to keep this similar to the naming of the current RAS trace events (right now we have mc_event, arm_event, aer_event, etc.). I would suggest using "arm_err_info_event" since this is handling the error information structures of the arm errors.
>>>>> +
>>>>> +    TP_PROTO(const struct cper_arm_err_info *err),
>>>>> +
>>>>> +    TP_ARGS(err),
>>>>> +
>>>>> +    TP_STRUCT__entry(
>>>>> +        __field(u8, type)
>>>>> +        __field(u16, multiple_error)
>>>>> +        __field(u8, flags)
>>>>> +        __field(u64, error_info)
>>>>> +        __field(u64, virt_fault_addr)
>>>>> +        __field(u64, physical_fault_addr)
>>>> Validation bits should also be a part of this structure that way user space tools will know which of these fields are valid.
>>> Could we use the default value to check the validation which we have checked in TP_fast_assign?
> Yes, true...I guess we really don't need the validation bits then.
>>>>> +    ),
>>>>> +
>>>>> +    TP_fast_assign(
>>>>> +        __entry->type = err->type;
>>>>> +
>>>>> +        if (err->validation_bits & CPER_ARM_INFO_VALID_MULTI_ERR)
>>>>> +            __entry->multiple_error = err->multiple_error;
>>>>> +        else
>>>>> +            __entry->multiple_error = ~0;
>>>>> +
>>>>> +        if (err->validation_bits & CPER_ARM_INFO_VALID_FLAGS)
>>>>> +            __entry->flags = err->flags;
>>>>> +        else
>>>>> +            __entry->flags = ~0;
>>>>> +
>>>>> +        if (err->validation_bits & CPER_ARM_INFO_VALID_ERR_INFO)
>>>>> +            __entry->error_info = err->error_info;
>>>>> +        else
>>>>> +            __entry->error_info = 0ULL;
>>>>> +
>>>>> +        if (err->validation_bits & CPER_ARM_INFO_VALID_VIRT_ADDR)
>>>>> +            __entry->virt_fault_addr = err->virt_fault_addr;
>>>>> +        else
>>>>> +            __entry->virt_fault_addr = 0ULL;
>>>>> +
>>>>> +        if (err->validation_bits & CPER_ARM_INFO_VALID_PHYSICAL_ADDR)
>>>>> +            __entry->physical_fault_addr = err->physical_fault_addr;
>>>>> +        else
>>>>> +            __entry->physical_fault_addr = 0ULL;
>>>>> +    ),
>>>>> +
>>>>> +    TP_printk("ARM Processor Error: type %s; count: %u; flags: %s;"
>>>> I think the "ARM Processor Error:" part of this should just be removed. Here's the output with this removed and the trace event renamed to arm_err_info_event. I think this looks much cleaner and matches the style used with the arm_event.
>>>>
>>>>            <idle>-0     [020] .ns.   366.592434: arm_event: affinity level: 2; MPIDR: 0000000000000000; MIDR: 00000000510f8000; running state: 1; PSCI state: 0
>>>>            <idle>-0     [020] .ns.   366.592437: arm_err_info_event: type cache error; count: 0; flags: 0x3; error info: 0000000000c20058; virtual address: 0000000000000000; physical address: 0000000000000000
>> As this section is ARM Processor Error Section, how about use arm_proc_err_event?
> This is not for the ARM Processor Error Section, that is what the arm_event is handling. What you are adding this trace support for here is called the ARM Processor Error Information (UEFI 2.6 spec section N.2.4.4.1). So I think your trace event here should be called arm_err_info_event. This will also be consistent with the other two trace events that I'm planning on adding:
> 
> arm_ctx_info_event: ARM Processor Context Information (UEFI 2.6 section N.2.4.4.2)
> arm_vendor_info_event: This is the "Vendor Specific Error Information" in the ARM Processor Error Section (Table 260). It's possible I may just add this into the arm_event trace event, but I haven't looked into it enough yet.
> 

OK, I see. Thanks for your explanation.

> Thanks,
> Tyler
> 

-- 
Thanks,
Xie XiuQi