linux-kernel - Re: [PATCH] f2fs: enable atgc if atgc_age_threshold from user is less than elapsed

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Date: Fri, 31 May 2024 10:15:36 +0800
From: Zhiguo Niu <niuzhiguo84@...il.com>
To: Chao Yu <chao@...nel.org>
Cc: Zhiguo Niu <zhiguo.niu@...soc.com>, jaegeuk@...nel.org, 
	linux-f2fs-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org, 
	ke.wang@...soc.com
Subject: Re: [PATCH] f2fs: enable atgc if atgc_age_threshold from user is less
 than elapsed_time

On Fri, May 31, 2024 at 10:04 AM Chao Yu <chao@...nel.org> wrote:
>
> On 2024/5/30 17:49, Zhiguo Niu wrote:
> > On Mon, May 27, 2024 at 12:07 PM Zhiguo Niu <niuzhiguo84@...il.com> wrote:
> >>
> >> On Mon, May 27, 2024 at 11:49 AM Chao Yu <chao@...nel.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， more than atgc default threshold ), atgc cannot be dynamically
> >> enabled.
> >>
> >> If the user is used to not restarting the phone after turning it on,
> >> it will be difficult to use atgc.
> >> thanks!
> > Hi Chao,
> > Do you have any suggestions or comments on this?
>
> Zhiguo,
>
> I remember that atgc can not be enabled at runtime due to some reasons, but
> I need some time to recall and check the details...
>
> Thanks,
Hi Chao,
OK, Thanks for your help.
>
> > thanks！
> >
> >>>
> >>>>
> >>>> It is better to enable atgc dynamiclly when user change atgc_age_threshold
> >>>> meanwhile this vale is less than elapsed_time and ATGC mount option is on.
> >>>>
> >>>> Signed-off-by: Zhiguo Niu <zhiguo.niu@...soc.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_info *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 type,
> >>>>                                        unsigned int start, unsigned int end);
> >>>>    int f2fs_allocate_new_section(struct f2fs_sb_info *sbi, int type, bool 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_info *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 = CURSEG_I(sbi, CURSEG_ALL_DATA_ATGC);
> >>>>        int ret = 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 type)
> >>>> 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 = t;
> >>>> +             if (sbi->am.atgc_enabled)
> >>>> +                     return count;
> >>>> +
> >>>> +             if (test_opt(sbi, ATGC) &&
> >>>> +                     le64_to_cpu(sbi->ckpt->elapsed_time) >= t) {
> >>>> +                     if (f2fs_init_atgc_curseg(sbi))
> >>>> +                             return -EINVAL;
> >>>> +                     sbi->am.atgc_enabled = true;
> >>>> +             }
> >>>> +             return count;
> >>>> +     }
> >>>> +
> >>>>        if (!strcmp(a->attr.name, "gc_segment_mode")) {
> >>>>                if (t < MAX_GC_MODE)
> >>>>                        sbi->gc_segment_mode = t;