Re: Lots of fastmap writes

Zhihao Cheng
2024-06-14T12:28:53Z

在 2024/6/14 19:42, Rickard X Andersson 写道:
> On 6/4/24 03:52, Zhihao Cheng wrote:

[...]
>>
>> BTW, after applying the patches, the kernel should run on a new flash,
>> the improved wear-leveling algorithm cannot rescue the worn out image.
>>
>
> Thanks for the patches!
>
> I have backported the patches to Linux kernel 6.1. Do you think the
> patches are safe to apply to Linux kernel 6.1?

Yes, it's okay. I have backported the patches to our product(kernel
v5.10) and it works fine.
>
> Another thing, would it not be possible to rescue that particular worn
> out device by simply turning fastmap off on that device?
>

Can I regard the rescuing as making erase counters become normal
again(max - min <= UBI_WL_THRESHOLD)? If so, I'm afraid that not all
PEBs can be rescued, according to get_peb_for_wl().
For example: PB, PC cannot be rescued, unless PA is taken for writing
and then wl is just right scheduled.

ubi->free tree:
29600(PB)
1(PA) 29600(PC)