Re: [PATCH 1/2] f2fs: pass down write hints to block layer for bufferd write

From: Chao Yu
Date: Thu Nov 30 2017 - 01:33:09 EST


On 2017/11/28 8:23, Hyunchul Lee wrote:
> From: Hyunchul Lee <cheol.lee@xxxxxxx>
>
> This implements which hint is passed down to block layer
> for datas from the specific segment type.
>
> segment type hints
> ------------ -----
> COLD_NODE & COLD_DATA WRITE_LIFE_EXTREME
> WARM_DATA WRITE_LIFE_NONE
> HOT_NODE & WARM_NODE WRITE_LIFE_LONG
> HOT_DATA WRITE_LIFE_MEDIUM
> META_DATA WRITE_LIFE_SHORT

The correspondence looks good to me.

>
> Many thanks to Chao Yu and Jaegeuk Kim for comments to
> implement this patch.
>
> Signed-off-by: Hyunchul Lee <cheol.lee@xxxxxxx>
> ---
> fs/f2fs/data.c | 1 +
> fs/f2fs/f2fs.h | 2 ++
> fs/f2fs/segment.c | 29 +++++++++++++++++++++++++++++
> fs/f2fs/super.c | 2 ++
> 4 files changed, 34 insertions(+)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index a7ae418..0919a43 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -437,6 +437,7 @@ int f2fs_submit_page_write(struct f2fs_io_info *fio)
> }
> io->bio = __bio_alloc(sbi, fio->new_blkaddr,
> BIO_MAX_PAGES, false);
> + io->bio->bi_write_hint = io->write_hint;

Need to assign bi_write_hint for IPU path?

- rewrite_data_page
- f2fs_submit_page_bio

> io->fio = *fio;
> }
>
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 7bcd148..be3cb0c 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -969,6 +969,7 @@ struct f2fs_bio_info {
> struct rw_semaphore io_rwsem; /* blocking op for bio */
> spinlock_t io_lock; /* serialize DATA/NODE IOs */
> struct list_head io_list; /* track fios */
> + enum rw_hint write_hint;

Add missing comment?

> };
>
> #define FDEV(i) (sbi->devs[i])
> @@ -2674,6 +2675,7 @@ int lookup_journal_in_cursum(struct f2fs_journal *journal, int type,
> int __init create_segment_manager_caches(void);
> void destroy_segment_manager_caches(void);
> int rw_hint_to_seg_type(enum rw_hint hint);
> +enum rw_hint io_type_to_rw_hint(enum page_type page, enum temp_type temp);
>
> /*
> * checkpoint.c
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index c117e09..0570db7 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -2446,6 +2446,35 @@ int rw_hint_to_seg_type(enum rw_hint hint)
> }
> }
>

It will be better to copy commit log here to declare correspondence
more clearly.

Thanks,

> +enum rw_hint io_type_to_rw_hint(enum page_type page, enum temp_type temp)
> +{
> + if (page == DATA) {
> + switch (temp) {
> + case WARM:
> + return WRITE_LIFE_NONE;
> + case COLD:
> + return WRITE_LIFE_EXTREME;
> + case HOT:
> + return WRITE_LIFE_MEDIUM;
> + default:
> + return WRITE_LIFE_NOT_SET;
> + }
> + } else if (page == NODE) {
> + switch (temp) {
> + case WARM:
> + case HOT:
> + return WRITE_LIFE_LONG;
> + case COLD:
> + return WRITE_LIFE_EXTREME;
> + default:
> + return WRITE_LIFE_NOT_SET;
> + }
> +
> + } else {
> + return WRITE_LIFE_SHORT;
> + }
> +}
> +
> static int __get_segment_type_2(struct f2fs_io_info *fio)
> {
> if (fio->type == DATA)
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index a6c5dd4..51c19a0 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -2508,6 +2508,8 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> sbi->write_io[i][j].bio = NULL;
> spin_lock_init(&sbi->write_io[i][j].io_lock);
> INIT_LIST_HEAD(&sbi->write_io[i][j].io_list);
> + sbi->write_io[i][j].write_hint =
> + io_type_to_rw_hint(i, j);
> }
> }
>
>