Re: [PATCH 2/2] f2fs:use fggc_set_cold_data instead of set_cold_data in fggc

[Jaegeuk Kim <jaegeuk@kernel.org>]

On 02/23, Hou Pengyang wrote:
> On 2017/2/23 8:39, Jaegeuk Kim wrote:
> > Hi Pengyang,
> > 
> > On 02/22, Hou Pengyang wrote:
> > > When no dirty colde segment for fggc ssr, we do NOT set_cold_data.
> > 
> > The get_ssr_segment() finds a victim segment across all the hot/warm/cold data
> > logs. When does this happen?
> > 
> Oh, I miss the travel across hot/warm/cold, sorry.
> how about the following filter in get_victim_segment, which can avoid
> unnecessary afterwards bitmap scanning.

Yup, it makes sense.

Thanks,

> 
> Thanks,
> 
> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> index a0eed23..00791d2 100644
> --- a/fs/f2fs/gc.c
> +++ b/fs/f2fs/gc.c
> @@ -290,9 +290,16 @@ static int get_victim_by_default(struct f2fs_sb_info
> *sbi,
>         unsigned int secno, last_victim;
>         unsigned int last_segment = MAIN_SEGS(sbi);
>         unsigned int nsearched = 0;
> +       int nr_dirty;
> 
>         mutex_lock(&dirty_i->seglist_lock);
> 
> +       if (alloc_mode == SSR) {
> +               nr_dirty = dirty_i->nr_dirty[type];
> +               if (!nr_dirty)
> +                       goto out;
> +       }
> +
>         p.alloc_mode = alloc_mode;
>         select_policy(sbi, gc_type, type, &p);
> 
> 
> > Thanks,
> > 
> > > 
> > > Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
> > > ---
> > >   fs/f2fs/gc.c | 21 ++++++++++++++++++++-
> > >   1 file changed, 20 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> > > index 4ee749f..a0eed23 100644
> > > --- a/fs/f2fs/gc.c
> > > +++ b/fs/f2fs/gc.c
> > > @@ -666,6 +666,25 @@ static void move_encrypted_block(struct inode *inode, block_t bidx,
> > >   	f2fs_put_page(page, 1);
> > >   }
> > > 
> > > +/*
> > > + * If NOT enough dirty cold data segments for fggc, fggc would consume
> > > + * a valuable free segment, which would slow down the fggc procedure,
> > > + * If there are NO COLD dirty segment, we do not set_cold_page.
> > > + */
> > > +static void fggc_set_cold_data(struct page *page)
> > > +{
> > > +	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
> > > +	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
> > > +	int nr_cold_dirties;
> > > +
> > > +	mutex_lock(&dirty_i->seglist_lock);
> > > +	nr_cold_dirties = dirty_i->nr_dirty[DIRTY_COLD_DATA];
> > > +	mutex_unlock(&dirty_i->seglist_lock);
> > > +
> > > +	if (nr_cold_dirties)
> > > +		set_cold_data(page);
> > > +
> > > +}
> > >   static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
> > >   							unsigned int segno, int off)
> > >   {
> > > @@ -706,7 +725,7 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
> > >   			remove_dirty_inode(inode);
> > >   		}
> > > 
> > > -		set_cold_data(page);
> > > +		fggc_set_cold_data(page);
> > > 
> > >   		err = do_write_data_page(&fio);
> > >   		if (err == -ENOMEM && is_dirty) {
> > > --
> > > 2.10.1
> > > 
> > > 
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> > > _______________________________________________
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> > > Linux-f2fs-devel@lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> > 
> > .
> > 
> 

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