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In-Reply-To: <1d67715b-5f88-4940-969d-e098fd80ae2a@kernel.org>
From: Zhiguo Niu <niuzhiguo84@gmail.com>
Date: Mon, 27 May 2024 12:07:09 +0800
Message-ID: <CAHJ8P3LXYWQ+bLZHPn_5FLu3oi83ei8C9ZCzAXwa9oBdEKVDNA@mail.gmail.com>
Subject: Re: [PATCH] f2fs: enable atgc if atgc_age_threshold from user is less
 than elapsed_time
To: Chao Yu <chao@kernel.org>
Cc: Zhiguo Niu <zhiguo.niu@unisoc.com>, jaegeuk@kernel.org, 
	linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, 
	ke.wang@unisoc.com
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On Mon, May 27, 2024 at 11:49=E2=80=AFAM Chao Yu <chao@kernel.org> wrote:
>
> On 2024/5/20 19:36, Zhiguo Niu wrote:
> > Now atgc can be enabled based on the following conditions:
> > -ATGC mount option is set
> > -elapsed_time is more than atgc_age_threshold already
> > but these conditions are check when umounted->mounted device again.
> > If the device has not be umounted->mounted for a long time, atgc can
> > not work even the above conditions met.
>
> Zhiguo, I didn't get it, can you please explain more about this issue?
>
> Thanks,
Hi Chao,

At present, the point of atgc enale is checked during the mount
process. What I mean is that if a device has not been rebooted
(re-mounted) for a long time, even if the above two conditions are
met(ATGC mount option is set, and the device has been powered on long
enough=EF=BC=8C more than atgc default threshold ), atgc cannot be dynamica=
lly
enabled.

If the user is used to not restarting the phone after turning it on,
it will be difficult to use atgc.
thanks!
>
> >
> > It is better to enable atgc dynamiclly when user change atgc_age_thresh=
old
> > meanwhile this vale is less than elapsed_time and ATGC mount option is =
on.
> >
> > Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
> > ---
> >   fs/f2fs/f2fs.h    |  1 +
> >   fs/f2fs/segment.c |  9 ++++-----
> >   fs/f2fs/sysfs.c   | 16 ++++++++++++++++
> >   3 files changed, 21 insertions(+), 5 deletions(-)
> >
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index 1974b6a..e441d2d 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -3694,6 +3694,7 @@ void f2fs_clear_prefree_segments(struct f2fs_sb_i=
nfo *sbi,
> >   int f2fs_init_inmem_curseg(struct f2fs_sb_info *sbi);
> >   void f2fs_save_inmem_curseg(struct f2fs_sb_info *sbi);
> >   void f2fs_restore_inmem_curseg(struct f2fs_sb_info *sbi);
> > +int f2fs_init_atgc_curseg(struct f2fs_sb_info *sbi);
> >   int f2fs_allocate_segment_for_resize(struct f2fs_sb_info *sbi, int ty=
pe,
> >                                       unsigned int start, unsigned int =
end);
> >   int f2fs_allocate_new_section(struct f2fs_sb_info *sbi, int type, boo=
l force);
> > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> > index 71dc8042..44923d4 100644
> > --- a/fs/f2fs/segment.c
> > +++ b/fs/f2fs/segment.c
> > @@ -2931,14 +2931,11 @@ static int get_atssr_segment(struct f2fs_sb_inf=
o *sbi, int type,
> >       return ret;
> >   }
> >
> > -static int __f2fs_init_atgc_curseg(struct f2fs_sb_info *sbi)
> > +int f2fs_init_atgc_curseg(struct f2fs_sb_info *sbi)
> >   {
> >       struct curseg_info *curseg =3D CURSEG_I(sbi, CURSEG_ALL_DATA_ATGC=
);
> >       int ret =3D 0;
> >
> > -     if (!sbi->am.atgc_enabled)
> > -             return 0;
> > -
> >       f2fs_down_read(&SM_I(sbi)->curseg_lock);
> >
> >       mutex_lock(&curseg->curseg_mutex);
> > @@ -2955,7 +2952,9 @@ static int __f2fs_init_atgc_curseg(struct f2fs_sb=
_info *sbi)
> >   }
> >   int f2fs_init_inmem_curseg(struct f2fs_sb_info *sbi)
> >   {
> > -     return __f2fs_init_atgc_curseg(sbi);
> > +     if (!sbi->am.atgc_enabled)
> > +             return 0;
> > +     return f2fs_init_atgc_curseg(sbi);
> >   }
> >
> >   static void __f2fs_save_inmem_curseg(struct f2fs_sb_info *sbi, int ty=
pe)
> > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> > index 09d3ecf..72676c5 100644
> > --- a/fs/f2fs/sysfs.c
> > +++ b/fs/f2fs/sysfs.c
> > @@ -673,6 +673,22 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
> >               return count;
> >       }
> >
> > +     if (!strcmp(a->attr.name, "atgc_age_threshold")) {
> > +             if (t < 0)
> > +                     return -EINVAL;
> > +             sbi->am.age_threshold =3D t;
> > +             if (sbi->am.atgc_enabled)
> > +                     return count;
> > +
> > +             if (test_opt(sbi, ATGC) &&
> > +                     le64_to_cpu(sbi->ckpt->elapsed_time) >=3D t) {
> > +                     if (f2fs_init_atgc_curseg(sbi))
> > +                             return -EINVAL;
> > +                     sbi->am.atgc_enabled =3D true;
> > +             }
> > +             return count;
> > +     }
> > +
> >       if (!strcmp(a->attr.name, "gc_segment_mode")) {
> >               if (t < MAX_GC_MODE)
> >                       sbi->gc_segment_mode =3D t;