Re: [PATCH v2 5/5] f2fs: support age threshold based garbage collection

[Chao Yu]

Jaegeuk,  I missed one ')' in this diff, thanks for fixing in upstream.

Thanks,

On 2020/9/1 2:01, Jaegeuk Kim wrote:
> Hi Chao,
>
> Applied. Thanks.
>
> On 08/31, Chao Yu wrote:
> > Hi Jaegeuk,
> >
> > I've changed code a bit to fix some bugs, including:
> > - gc_idle = 3 (GC_IDLE_AT) description
> > - disallow set gc_idle to 3 if atgc is off
> > - keep compatibility with checkpoint disabling
> >
> > Could you please check and merge below diff?
> >
> > From: Chao Yu <yuchao0@xxxxxxxxxx>
> >
> > Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> > ---
> >   Documentation/ABI/testing/sysfs-fs-f2fs |  3 ++-
> >   fs/f2fs/gc.c                            | 12 +++++++++++-
> >   fs/f2fs/sysfs.c                         | 11 ++++++++---
> >   3 files changed, 21 insertions(+), 5 deletions(-)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
> > index 7f730c4c8df2..834d0becae6d 100644
> > --- a/Documentation/ABI/testing/sysfs-fs-f2fs
> > +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> > @@ -22,7 +22,8 @@ Contact:	"Namjae Jeon" <namjae.jeon@xxxxxxxxxxx>
> >   Description:	Controls the victim selection policy for garbage collection.
> >   		Setting gc_idle = 0(default) will disable this option. Setting
> >   		gc_idle = 1 will select the Cost Benefit approach & setting
> > -		gc_idle = 2 will select the greedy approach.
> > +		gc_idle = 2 will select the greedy approach & setting
> > +		gc_idle = 3 will select the age-threshold based approach.
> >
> >   What:		/sys/fs/f2fs/<disk>/reclaim_segments
> >   Date:		October 2013
> > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> > index 6413886e52d4..3c0edb8b4cc5 100644
> > --- a/fs/f2fs/gc.c
> > +++ b/fs/f2fs/gc.c
> > @@ -388,6 +388,16 @@ static void add_victim_entry(struct f2fs_sb_info *sbi,
> >   	unsigned long long mtime = 0;
> >   	unsigned int i;
> >
> > +	if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
> > +		if (p->gc_mode == GC_AT &&
> > +			get_valid_blocks(sbi, segno, true) == 0)
> > +			return;
> > +
> > +		if (p->alloc_mode == AT_SSR &&
> > +			get_seg_entry(sbi, segno)->ckpt_valid_blocks == 0)
> > +			return;
> > +	}
> > +
> >   	for (i = 0; i < sbi->segs_per_sec; i++)
> >   		mtime += get_seg_entry(sbi, start + i)->mtime;
> >   	mtime = div_u64(mtime, sbi->segs_per_sec);
> > @@ -721,7 +731,7 @@ static int get_victim_by_default(struct f2fs_sb_info *sbi,
> >   		/* Don't touch checkpointed data */
> >   		if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
> >   					get_ckpt_valid_blocks(sbi, segno) &&
> > -					p.alloc_mode != SSR))
> > +					p.alloc_mode == LFS))
> >   			goto next;
> >   		if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
> >   			goto next;
> > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> > index 88ed9969cc86..bacfa9c35e6b 100644
> > --- a/fs/f2fs/sysfs.c
> > +++ b/fs/f2fs/sysfs.c
> > @@ -375,12 +375,17 @@ static ssize_t __sbi_store(struct f2fs_attr *a,
> >   		return count;
> >   	}
> >   	if (!strcmp(a->attr.name, "gc_idle")) {
> > -		if (t == GC_IDLE_CB)
> > +		if (t == GC_IDLE_CB) {
> >   			sbi->gc_mode = GC_IDLE_CB;
> > -		else if (t == GC_IDLE_GREEDY)
> > +		} else if (t == GC_IDLE_GREEDY) {
> >   			sbi->gc_mode = GC_IDLE_GREEDY;
> > -		else
> > +		} else if (t == GC_IDLE_AT) {
> > +			if (!sbi->am.atgc_enabled)
> > +				return -EINVAL;
> > +			sbi->gc_mode = GC_AT;
> > +		} else {
> >   			sbi->gc_mode = GC_NORMAL;
> > +		}
> >   		return count;
> >   	}
> >
> > --
> > 2.26.2
> .