Re: [f2fs-dev] [PATCH] f2fs: assign the write hint per stream by default

From: Jaegeuk Kim
Date: Fri Apr 19 2024 - 13:53:41 EST


On 04/18, Chao Yu wrote:
> On 2024/4/18 5:12, Jaegeuk Kim wrote:
> > This reverts commit 930e2607638d ("f2fs: remove obsolete whint_mode"), as we
> > decide to pass write hints to the disk.
> >
> > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> > ---
> > Documentation/filesystems/f2fs.rst | 29 +++++++++++++++
> > fs/f2fs/data.c | 2 +
> > fs/f2fs/f2fs.h | 2 +
> > fs/f2fs/segment.c | 59 ++++++++++++++++++++++++++++++
> > 4 files changed, 92 insertions(+)
> >
> > diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
> > index efc3493fd6f8..68a0885fb5e6 100644
> > --- a/Documentation/filesystems/f2fs.rst
> > +++ b/Documentation/filesystems/f2fs.rst
> > @@ -774,6 +774,35 @@ In order to identify whether the data in the victim segment are valid or not,
> > F2FS manages a bitmap. Each bit represents the validity of a block, and the
> > bitmap is composed of a bit stream covering whole blocks in main area.
> > +Write-hint Policy
> > +-----------------
> > +
> > +F2FS sets the whint all the time with the below policy.
>
> No user-based mode?

Not anymore, as there's no user.

>
> Thanks,
>
> > +
> > +===================== ======================== ===================
> > +User F2FS Block
> > +===================== ======================== ===================
> > +N/A META WRITE_LIFE_NONE|REQ_META
> > +N/A HOT_NODE WRITE_LIFE_NONE
> > +N/A WARM_NODE WRITE_LIFE_MEDIUM
> > +N/A COLD_NODE WRITE_LIFE_LONG
> > +ioctl(COLD) COLD_DATA WRITE_LIFE_EXTREME
> > +extension list " "
> > +
> > +-- buffered io
> > +N/A COLD_DATA WRITE_LIFE_EXTREME
> > +N/A HOT_DATA WRITE_LIFE_SHORT
> > +N/A WARM_DATA WRITE_LIFE_NOT_SET
> > +
> > +-- direct io
> > +WRITE_LIFE_EXTREME COLD_DATA WRITE_LIFE_EXTREME
> > +WRITE_LIFE_SHORT HOT_DATA WRITE_LIFE_SHORT
> > +WRITE_LIFE_NOT_SET WARM_DATA WRITE_LIFE_NOT_SET
> > +WRITE_LIFE_NONE " WRITE_LIFE_NONE
> > +WRITE_LIFE_MEDIUM " WRITE_LIFE_MEDIUM
> > +WRITE_LIFE_LONG " WRITE_LIFE_LONG
> > +===================== ======================== ===================
> > +
> > Fallocate(2) Policy
> > -------------------
> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > index 5d641fac02ba..ed7d08785fcf 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -465,6 +465,8 @@ static struct bio *__bio_alloc(struct f2fs_io_info *fio, int npages)
> > } else {
> > bio->bi_end_io = f2fs_write_end_io;
> > bio->bi_private = sbi;
> > + bio->bi_write_hint = f2fs_io_type_to_rw_hint(sbi,
> > + fio->type, fio->temp);
> > }
> > iostat_alloc_and_bind_ctx(sbi, bio, NULL);
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index dd530dc70005..b3b878acc86b 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -3745,6 +3745,8 @@ void f2fs_destroy_segment_manager(struct f2fs_sb_info *sbi);
> > int __init f2fs_create_segment_manager_caches(void);
> > void f2fs_destroy_segment_manager_caches(void);
> > int f2fs_rw_hint_to_seg_type(enum rw_hint hint);
> > +enum rw_hint f2fs_io_type_to_rw_hint(struct f2fs_sb_info *sbi,
> > + enum page_type type, enum temp_type temp);
> > unsigned int f2fs_usable_segs_in_sec(struct f2fs_sb_info *sbi,
> > unsigned int segno);
> > unsigned int f2fs_usable_blks_in_seg(struct f2fs_sb_info *sbi,
> > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> > index f0da516ba8dc..daa94669f7ee 100644
> > --- a/fs/f2fs/segment.c
> > +++ b/fs/f2fs/segment.c
> > @@ -3364,6 +3364,65 @@ int f2fs_rw_hint_to_seg_type(enum rw_hint hint)
> > }
> > }
> > +/*
> > + * This returns write hints for each segment type. This hints will be
> > + * passed down to block layer as below by default.
> > + *
> > + * User F2FS Block
> > + * ---- ---- -----
> > + * META WRITE_LIFE_NONE|REQ_META
> > + * HOT_NODE WRITE_LIFE_NONE
> > + * WARM_NODE WRITE_LIFE_MEDIUM
> > + * COLD_NODE WRITE_LIFE_LONG
> > + * ioctl(COLD) COLD_DATA WRITE_LIFE_EXTREME
> > + * extension list " "
> > + *
> > + * -- buffered io
> > + * COLD_DATA WRITE_LIFE_EXTREME
> > + * HOT_DATA WRITE_LIFE_SHORT
> > + * WARM_DATA WRITE_LIFE_NOT_SET
> > + *
> > + * -- direct io
> > + * WRITE_LIFE_EXTREME COLD_DATA WRITE_LIFE_EXTREME
> > + * WRITE_LIFE_SHORT HOT_DATA WRITE_LIFE_SHORT
> > + * WRITE_LIFE_NOT_SET WARM_DATA WRITE_LIFE_NOT_SET
> > + * WRITE_LIFE_NONE " WRITE_LIFE_NONE
> > + * WRITE_LIFE_MEDIUM " WRITE_LIFE_MEDIUM
> > + * WRITE_LIFE_LONG " WRITE_LIFE_LONG
> > + */
> > +enum rw_hint f2fs_io_type_to_rw_hint(struct f2fs_sb_info *sbi,
> > + enum page_type type, enum temp_type temp)
> > +{
> > + switch (type) {
> > + case DATA:
> > + switch (temp) {
> > + case WARM:
> > + return WRITE_LIFE_NOT_SET;
> > + case HOT:
> > + return WRITE_LIFE_SHORT;
> > + case COLD:
> > + return WRITE_LIFE_EXTREME;
> > + default:
> > + return WRITE_LIFE_NONE;
> > + }
> > + case NODE:
> > + switch (temp) {
> > + case WARM:
> > + return WRITE_LIFE_MEDIUM;
> > + case HOT:
> > + return WRITE_LIFE_NONE;
> > + case COLD:
> > + return WRITE_LIFE_LONG;
> > + default:
> > + return WRITE_LIFE_NONE;
> > + }
> > + case META:
> > + return WRITE_LIFE_NONE;
> > + default:
> > + return WRITE_LIFE_NONE;
> > + }
> > +}
> > +
> > static int __get_segment_type_2(struct f2fs_io_info *fio)
> > {
> > if (fio->type == DATA)