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From:   Daeho Jeong <daeho43@gmail.com>
Date:   Wed, 10 Mar 2021 13:30:52 +0900
Message-ID: <CACOAw_yvqCpq8i_XfmyWVWdtZhOQf4itw2D5Xxhk97RgWmVing@mail.gmail.com>
Subject: Re: [f2fs-dev] [PATCH v2] f2fs: add sysfs nodes to get accumulated
 compression info
To:     Chao Yu <yuchao0@huawei.com>
Cc:     linux-kernel@vger.kernel.org,
        linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com,
        Daeho Jeong <daehojeong@google.com>
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We've reconsidered this feature and decided to get just runtime info
of them, not persistent on disk.
I am re-writing it.

Thanks,

2021=EB=85=84 3=EC=9B=94 10=EC=9D=BC (=EC=88=98) =EC=98=A4=EC=A0=84 10:31, =
Chao Yu <yuchao0@huawei.com>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
>
> On 2021/3/9 21:00, Daeho Jeong wrote:
> > 2021=EB=85=84 3=EC=9B=94 9=EC=9D=BC (=ED=99=94) =EC=98=A4=ED=9B=84 6:22=
, Chao Yu <yuchao0@huawei.com>=EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1:
> >>
> >> On 2021/3/5 10:24, Daeho Jeong wrote:
> >>> From: Daeho Jeong <daehojeong@google.com>
> >>>
> >>> Added acc_compr_inodes to show accumulated compressed inode count and
> >>> acc_compr_blocks to show accumulated secured block count with
> >>
> >> I noticed that these stat numbers are recorded in extra reserved area =
in
> >> hot node curseg journal, the journal will be persisted only for umount
> >> or fastboot checkpoint, so the numbers are not so accurate... does thi=
s
> >> satisfy your requirement?
> >>
> >
> > Yes, we are satisfied with just getting rough number of them. But, it
>
> Alright,
>
> > would be better if you suggest more accurate way. :)
>
> I think this is the cheapest way to store rough number, otherwise it need=
s to change
> f2fs_checkpoint structure layout or add a new inner inode to persist thes=
e stat
> numbers if we want more accurate one.
>
> >
> >>> compression in sysfs. These can be re-initialized to "0" by writing "=
0"
> >>> value in one of both.
> >>
> >> Why do we allow reset the stat numbers?
> >>
> >
> > Actually, I want to have a way to clear any stale number of them, but
> > I agree we don't need this.
> >
> >> Why not covering all code with macro CONFIG_F2FS_FS_COMPRESSION, since=
 these
> >> numbers are only be updated when we enable compression.
> >>
> >
> > I wanted to keep the info even in the kernel with doesn't support
> > per-file compression if those had been written once. What do you
> > think?
>
> Sure, if so it's fine to me. :)
>
> Thanks,
>
> >
> >> Thanks,
> > .
> >