On 04/14, Daejun Park wrote:
> This patch enables submit reset zone command asynchornously. It helps
> decrease average latency of write IOs in high utilization scenario by
> faster checkpointing.
>
> Signed-off-by: Daejun Park <daejun7.park@xxxxxxxxxxx>
> ---
> Documentation/filesystems/f2fs.rst | 4 ++
> fs/f2fs/f2fs.h | 1 +
> fs/f2fs/segment.c | 92 +++++++++++++++++++++++++++++-
> fs/f2fs/super.c | 8 +++
> include/trace/events/f2fs.h | 18 +++++-
> 5 files changed, 119 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
> index 2055e72871fe..4cfabf831a79 100644
> --- a/Documentation/filesystems/f2fs.rst
> +++ b/Documentation/filesystems/f2fs.rst
> @@ -342,6 +342,10 @@ discard_unit=%s Control discard unit, the argument can be "block", "segment"
> default, it is helpful for large sized SMR or ZNS devices to
> reduce memory cost by getting rid of fs metadata supports small
> discard.
> +async_reset_zone Enable the RESET WRITE POINTER command to be submitted asynchronously.
> + With this option, the RESET WRITE POINTER command can be processed by
> + the discard thread like a discard command. It can reduce checkpoint
> + latency by asynchronously checking for completion of the RESET WRITE POINTER command.
Do we need to set this by default instead of mount option?
> memory=%s Control memory mode. This supports "normal" and "low" modes.
> "low" mode is introduced to support low memory devices.
> Because of the nature of low memory devices, in this mode, f2fs
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 4e2596dacbf1..021e55c5d1a8 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -167,6 +167,7 @@ struct f2fs_mount_info {
> * be aligned to this unit: block,
> * segment or section
> */
> + bool async_zone_reset; /* async zone reset */
> struct fscrypt_dummy_policy dummy_enc_policy; /* test dummy encryption */
> block_t unusable_cap_perc; /* percentage for cap */
> block_t unusable_cap; /* Amount of space allowed to be
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 45128694eefa..60cfe97c9dbd 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -1189,6 +1189,46 @@ static void __init_discard_policy(struct f2fs_sb_info *sbi,
> static void __update_discard_tree_range(struct f2fs_sb_info *sbi,
> struct block_device *bdev, block_t lstart,
> block_t start, block_t len);
> +
> +#ifdef CONFIG_BLK_DEV_ZONED
> +static int __submit_zone_reset_cmd(struct f2fs_sb_info *sbi,
> + struct discard_cmd *dc, blk_opf_t flag,
> + struct list_head *wait_list,
> + unsigned int *issued)
> +{
> + struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
> + struct block_device *bdev = dc->bdev;
> + struct bio *bio = bio_alloc(bdev, 0, REQ_OP_ZONE_RESET | flag, GFP_NOFS);
> + unsigned long flags;
> +
> + trace_f2fs_issue_reset_zone(bdev, SECTOR_FROM_BLOCK(dc->di.start));
> +
> + spin_lock_irqsave(&dc->lock, flags);
> + dc->state = D_SUBMIT;
> + dc->bio_ref++;
> + spin_unlock_irqrestore(&dc->lock, flags);
> +
> + if (issued)
> + (*issued)++;
> +
> + atomic_inc(&dcc->queued_discard);
> + dc->queued++;
> + list_move_tail(&dc->list, wait_list);
> +
> + /* sanity check on discard range */
> + __check_sit_bitmap(sbi, dc->di.lstart, dc->di.lstart + dc->di.len);
> +
> + bio->bi_iter.bi_sector = SECTOR_FROM_BLOCK(dc->di.start);
> + bio->bi_private = dc;
> + bio->bi_end_io = f2fs_submit_discard_endio;
> + submit_bio(bio);
> +
> + atomic_inc(&dcc->issued_discard);
> +
> + return 0;
> +}
> +#endif
> +
> /* this function is copied from blkdev_issue_discard from block/blk-lib.c */
> static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
> struct discard_policy *dpolicy,
> @@ -1210,6 +1250,11 @@ static int __submit_discard_cmd(struct f2fs_sb_info *sbi,
> if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
> return 0;
>
> +#ifdef CONFIG_BLK_DEV_ZONED
> + if (f2fs_sb_has_blkzoned(sbi) && bdev_is_zoned(bdev))
> + return __submit_zone_reset_cmd(sbi, dc, flag, wait_list, issued);
> +#endif
> +
> trace_f2fs_issue_discard(bdev, dc->di.start, dc->di.len);
>
> lstart = dc->di.lstart;
> @@ -1454,21 +1499,42 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi,
> }
> }
>
> +#ifdef CONFIG_BLK_DEV_ZONED
> +static void __queue_zone_reset_cmd(struct f2fs_sb_info *sbi,
> + struct block_device *bdev, block_t blkstart, block_t blklen)
> +{
> + block_t lblkstart = blkstart;
> +
> + if (f2fs_is_multi_device(sbi)) {
> + int devi = f2fs_target_device_index(sbi, blkstart);
> +
> + blkstart -= FDEV(devi).start_blk;
> + }
> +
> + trace_f2fs_queue_reset_zone(bdev, blkstart);
> +
> + mutex_lock(&SM_I(sbi)->dcc_info->cmd_lock);
> + __insert_discard_cmd(sbi, bdev, lblkstart, blkstart, blklen);
> + mutex_unlock(&SM_I(sbi)->dcc_info->cmd_lock);
> +}
> +#endif
> +
> static void __queue_discard_cmd(struct f2fs_sb_info *sbi,
> struct block_device *bdev, block_t blkstart, block_t blklen)
> {
> block_t lblkstart = blkstart;
>
> + trace_f2fs_queue_discard(bdev, blkstart, blklen);
> +
> if (!f2fs_bdev_support_discard(bdev))
> return;
>
> - trace_f2fs_queue_discard(bdev, blkstart, blklen);
> -
> if (f2fs_is_multi_device(sbi)) {
> int devi = f2fs_target_device_index(sbi, blkstart);
>
> blkstart -= FDEV(devi).start_blk;
> }
> +
> mutex_lock(&SM_I(sbi)->dcc_info->cmd_lock);
> __update_discard_tree_range(sbi, bdev, lblkstart, blkstart, blklen);
> mutex_unlock(&SM_I(sbi)->dcc_info->cmd_lock);
> @@ -1719,7 +1785,22 @@ static void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
> dc = __lookup_discard_cmd(sbi, blkaddr);
> if (dc) {
> if (dc->state == D_PREP) {
> +#ifdef CONFIG_BLK_DEV_ZONED
> + if (f2fs_sb_has_blkzoned(sbi) &&
> + bdev_is_zoned(dc->bdev)) {
> + struct discard_policy dpolicy;
> + /* force submit zone reset */
> + __init_discard_policy(sbi, &dpolicy,
> + DPOLICY_FORCE, 1);
> + __submit_discard_cmd(sbi, &dpolicy, dc, NULL);
> + dc->ref++;
> + need_wait = true;
> + } else {
> + __punch_discard_cmd(sbi, dc, blkaddr);
Can be consolidated in both cases below.
> + }
> +#else
> __punch_discard_cmd(sbi, dc, blkaddr);
> +#endif
> } else {
> dc->ref++;
> need_wait = true;
> @@ -1869,6 +1950,13 @@ static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
> blkstart, blklen);
> return -EIO;
> }
> +
> + if (likely(!is_sbi_flag_set(sbi, SBI_POR_DOING)) &&
> + F2FS_OPTION(sbi).async_zone_reset) {
> + __queue_zone_reset_cmd(sbi, bdev, lblkstart, blklen);
> + return 0;
> + }
Can make a sigle case above and below, if we set this by default.
> +
> trace_f2fs_issue_reset_zone(bdev, blkstart);
> return blkdev_zone_mgmt(bdev, REQ_OP_ZONE_RESET,
> sector, nr_sects, GFP_NOFS);
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 7d0202f7b317..48198112cbbc 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -162,6 +162,7 @@ enum {
> Opt_gc_merge,
> Opt_nogc_merge,
> Opt_discard_unit,
> + Opt_async_zone_reset,
> Opt_memory_mode,
> Opt_age_extent_cache,
> Opt_err,
> @@ -241,6 +242,7 @@ static match_table_t f2fs_tokens = {
> {Opt_gc_merge, "gc_merge"},
> {Opt_nogc_merge, "nogc_merge"},
> {Opt_discard_unit, "discard_unit=%s"},
> + {Opt_async_zone_reset, "async_zone_reset"},
> {Opt_memory_mode, "memory=%s"},
> {Opt_age_extent_cache, "age_extent_cache"},
> {Opt_err, NULL},
> @@ -1249,6 +1251,9 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
> }
> kfree(name);
> break;
> + case Opt_async_zone_reset:
> + F2FS_OPTION(sbi).async_zone_reset = true;
> + break;
> case Opt_memory_mode:
> name = match_strdup(&args[0]);
> if (!name)
> @@ -2047,6 +2052,9 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> if (test_opt(sbi, ATGC))
> seq_puts(seq, ",atgc");
>
> + if (F2FS_OPTION(sbi).async_zone_reset)
> + seq_puts(seq, ",async_zone_reset");
> +
> if (F2FS_OPTION(sbi).memory_mode == MEMORY_MODE_NORMAL)
> seq_printf(seq, ",memory=%s", "normal");
> else if (F2FS_OPTION(sbi).memory_mode == MEMORY_MODE_LOW)
> diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h
> index 99cbc5949e3c..ee1477de8324 100644
> --- a/include/trace/events/f2fs.h
> +++ b/include/trace/events/f2fs.h
> @@ -1512,7 +1512,7 @@ DEFINE_EVENT(f2fs_discard, f2fs_remove_discard,
> TP_ARGS(dev, blkstart, blklen)
> );
>
> -TRACE_EVENT(f2fs_issue_reset_zone,
> +DECLARE_EVENT_CLASS(f2fs_reset_zone,
>
> TP_PROTO(struct block_device *dev, block_t blkstart),
>
> @@ -1528,11 +1528,25 @@ TRACE_EVENT(f2fs_issue_reset_zone,
> __entry->blkstart = blkstart;
> ),
>
> - TP_printk("dev = (%d,%d), reset zone at block = 0x%llx",
> + TP_printk("dev = (%d,%d), zone at block = 0x%llx",
> show_dev(__entry->dev),
> (unsigned long long)__entry->blkstart)
> );
>
> +DEFINE_EVENT(f2fs_reset_zone, f2fs_queue_reset_zone,
> +
> + TP_PROTO(struct block_device *dev, block_t blkstart),
> +
> + TP_ARGS(dev, blkstart)
> +);
> +
> +DEFINE_EVENT(f2fs_reset_zone, f2fs_issue_reset_zone,
> +
> + TP_PROTO(struct block_device *dev, block_t blkstart),
> +
> + TP_ARGS(dev, blkstart)
> +);
> +
> TRACE_EVENT(f2fs_issue_flush,
>
> TP_PROTO(struct block_device *dev, unsigned int nobarrier,
> --
> 2.25.1
