Re: Error detection for microSD-based swap, buildworld failures on pi3

On 2/02/2022 3:10 pm, Mark Millard wrote:
> On 2022-Feb-1, at 18:52, MJ <[email protected]> wrote:
> 
>> On 2/02/2022 12:25 pm, Mark Millard wrote:
>>> On 2022-Feb-1, at 16:47, MJ <[email protected]> wrote:
>>>> On 2/02/2022 3:18 am, bob prohaska wrote:
>>>>> [new subject, different emphasis, old problem]
>>>>> On Mon, Jan 31, 2022 at 03:06:01PM -0800, Mark Millard wrote:
>>>>>>
>>>>>> One thing that could fit the behavior is if small part(s)
>>>>>> of the system c++ compiler (or libraires it uses) were
>>>>>> corrupted on that specific media. In that case, nothing
>>>>>> elsewhere would replicate the failures but a lot might
>>>>>> work without using the corrupted part(s), making the
>>>>>> failures not random.
>>>>> [spaced for emphasis]
>>>>>> Checking on that is part of why
>>>>>> I'd hoped to get a lldb report for a .sh/.cpp pair
>>>>>> leading to failure on your RPi3* in question.
>>>>>>
>>>>> If/when the stable/13 Pi3 finishes its -j1 single-user
>>>>> build/install cycle I'll make a point of trying the
>>>>> .sh/.cpp test under lldb.
>>>>> For most of their operational history both troublesome Pi3
>>>>> systems have had some of their swap on microSD. If there
>>>>> is no error detection at all for microSD-based storage
>>>>
>>>> Is this true? I would have thought it used some form of error detection in the firmware or in
>>>> the controller.
>>> The type of error and stage at which the error occurs matters.
>>> The firmware can not cover all issues that lead to corrupted
>>> content on media.
>>
>> I did not state it covers all corruption. However, I would be totally surprised if the controller in
>> ALL SD cards does not do error checking, whether ECC or even BCH. That remains my point.
> 
> I've a lot more context on Bob's problem and was mostly
> giving more context than he supplied. (My name is on the
> most nested text that he sent. I've been working with him
> for a while on this.)
> 

<snip>

Ok, understood, I will refrain. No more noise from me.
MJ