Re: Fwd: ubi: fastmap: Fix a series of wear leveling problems

[Zhihao Cheng]

在 2023/8/16 17:56, Bagas Sanjaya 写道:
Hi,
> Hi,
>
> I notice a bug report with proposed fixes on Bugzilla [1]. Quoting from it
> (only the first problem that is quoted):
>
> > Problem 1: large erase counter for single fastmap data PEB
> >
> > Config:
> > x86_64 qemu
> > flash: nandsim
> > CONFIG_MTD_UBI_WL_THRESHOLD=128
> > CONFIG_MTD_UBI_FASTMAP=y
> > ubi->beb_rsvd_pebs=0
> >
> > Running fsstress on ubifs for 3h(fastmap data PEB has large erase counter than others):
> > =========================================================
> > from              to     count      min      avg      max
> > ---------------------------------------------------------
> > 0        ..        9:        0        0        0        0
> > 10       ..       99:      532       84       92       99
> > 100      ..      999:    15787      100      147      229
> > 1000     ..     9999:       64     4699     4765     4826
> > 10000    ..    99999:        0        0        0        0
> > 100000   ..      inf:        1   272935   272935   272935
> > ---------------------------------------------------------
> > Total               :    16384       84      180   272935
> > PEB 8031(ec=272935) is always taken for fastmap data.
> >
> > After fix, running fsstress on ubifs for 12h(no pool reservation), no individual peb has big erase counter:
> > =========================================================
> > from              to     count      min      avg      max
> > ---------------------------------------------------------
> > 0        ..        9:        0        0        0        0
> > 10       ..       99:        0        0        0        0
> > 100      ..      999:    16320      609      642      705
> > 1000     ..     9999:        0        0        0        0
> > 10000    ..    99999:       64    18176    18234    18303
> > 100000   ..      inf:        0        0        0        0
> > ---------------------------------------------------------
> > Total               :    16384      609      710    18303
>
> See Bugzilla for the full thread (with other problems mentioned) and
> attached patch series that fixes them.
>
> Zhihao: I asked you on BZ to send your patches to linux-mtd list,
> but you didn't respond there. Would you like to send them for
> review?

Sorry for the delayed response. Yes, I have sent the fix patches in 
https://patchwork.ozlabs.org/project/linux-mtd/list/?series=368534.
Any suggestions are welcomed.


> Thanks.
>
> [1]: https://bugzilla.kernel.org/show_bug.cgi?id=217787