Re: [f2fs-dev] [PATCH v2] f2fs: rename checkpoint=merge mount option to checkpoint_merge

From: Daeho Jeong
Date: Tue Feb 02 2021 - 04:13:16 EST

If I understand it correctly, the only thing I have to do now is
remove "nocheckpoint_merge" now.
Am I correct? :)

2021년 2월 2일 (화) 오후 5:30, Chao Yu <yuchao0@xxxxxxxxxx>님이 작성:
>
> On 2021/2/2 16:02, Daeho Jeong wrote:
> > I chose the same step with "flush_merge", because it doesn't have
> > "noflush_merge".
>
> Oh, "noxxx" option was added only when we set the option by default in
> default_options(), when user want to disable the default option, it
> needs to use "noxxx" option, and then we will show this "noxxx" option
> string to user via show_options() to indicate that "noxxx" option is
> working now.
>
> Anyway I think we should fix to show "noflush_merge" option because we
> have set flush_merge by default.
>
> > Do you think we need that for both, "noflush_merge" and "nocheckpoint_merge"?
>
> For "nocheckpoint_merge", we can introduce this option only when we want
> to set "checkpoint_merge" by default.
>
> Here is the example from noinline_data:
>
> Commit 75342797988 ("f2fs: enable inline data by default")
>
> Thanks,
>
> >
> > I thought we needed to give some time to make this be turned on by
> > default. It might be a little radical. :)
> >
> > What do you think?
> >
> > 2021년 2월 2일 (화) 오후 4:40, Chao Yu <yuchao0@xxxxxxxxxx>님이 작성:
> >>
> >> On 2021/2/2 13:18, Daeho Jeong wrote:
> >>> From: Daeho Jeong <daehojeong@xxxxxxxxxx>
> >>>
> >>> As checkpoint=merge comes in, mount option setting related to checkpoint
> >>> had been mixed up and it became hard to understand. So, I separated
> >>> this option from "checkpoint=" and made another mount option
> >>> "checkpoint_merge" for this.
> >>>
> >>> Signed-off-by: Daeho Jeong <daehojeong@xxxxxxxxxx>
> >>> ---
> >>> v2: renamed "checkpoint=merge" to "checkpoint_merge"
> >>> ---
> >>> Documentation/filesystems/f2fs.rst | 6 +++---
> >>> fs/f2fs/super.c | 26 ++++++++++++++------------
> >>> 2 files changed, 17 insertions(+), 15 deletions(-)
> >>>
> >>> diff --git a/Documentation/filesystems/f2fs.rst b/Documentation/filesystems/f2fs.rst
> >>> index d0ead45dc706..475994ed8b15 100644
> >>> --- a/Documentation/filesystems/f2fs.rst
> >>> +++ b/Documentation/filesystems/f2fs.rst
> >>> @@ -247,9 +247,9 @@ checkpoint=%s[:%u[%]] Set to "disable" to turn off checkpointing. Set to "enabl
> >>> hide up to all remaining free space. The actual space that
> >>> would be unusable can be viewed at /sys/fs/f2fs/<disk>/unusable
> >>> This space is reclaimed once checkpoint=enable.
> >>> - Here is another option "merge", which creates a kernel daemon
> >>> - and makes it to merge concurrent checkpoint requests as much
> >>> - as possible to eliminate redundant checkpoint issues. Plus,
> >>> +checkpoint_merge When checkpoint is enabled, this can be used to create a kernel
> >>> + daemon and make it to merge concurrent checkpoint requests as
> >>> + much as possible to eliminate redundant checkpoint issues. Plus,
> >>> we can eliminate the sluggish issue caused by slow checkpoint
> >>> operation when the checkpoint is done in a process context in
> >>> a cgroup having low i/o budget and cpu shares. To make this
> >>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> >>> index 56696f6cfa86..d8603e6c4916 100644
> >>> --- a/fs/f2fs/super.c
> >>> +++ b/fs/f2fs/super.c
> >>> @@ -145,6 +145,7 @@ enum {
> >>> Opt_checkpoint_disable_cap_perc,
> >>> Opt_checkpoint_enable,
> >>> Opt_checkpoint_merge,
> >>> + Opt_nocheckpoint_merge,
> >>> Opt_compress_algorithm,
> >>> Opt_compress_log_size,
> >>> Opt_compress_extension,
> >>> @@ -215,7 +216,8 @@ static match_table_t f2fs_tokens = {
> >>> {Opt_checkpoint_disable_cap, "checkpoint=disable:%u"},
> >>> {Opt_checkpoint_disable_cap_perc, "checkpoint=disable:%u%%"},
> >>> {Opt_checkpoint_enable, "checkpoint=enable"},
> >>> - {Opt_checkpoint_merge, "checkpoint=merge"},
> >>> + {Opt_checkpoint_merge, "checkpoint_merge"},
> >>> + {Opt_nocheckpoint_merge, "nocheckpoint_merge"},
> >>> {Opt_compress_algorithm, "compress_algorithm=%s"},
> >>> {Opt_compress_log_size, "compress_log_size=%u"},
> >>> {Opt_compress_extension, "compress_extension=%s"},
> >>> @@ -946,6 +948,9 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
> >>> case Opt_checkpoint_merge:
> >>> set_opt(sbi, MERGE_CHECKPOINT);
> >>> break;
> >>> + case Opt_nocheckpoint_merge:
> >>> + clear_opt(sbi, MERGE_CHECKPOINT);
> >>> + break;
> >>> #ifdef CONFIG_F2FS_FS_COMPRESSION
> >>> case Opt_compress_algorithm:
> >>> if (!f2fs_sb_has_compression(sbi)) {
> >>> @@ -1142,12 +1147,6 @@ static int parse_options(struct super_block *sb, char *options, bool is_remount)
> >>> return -EINVAL;
> >>> }
> >>>
> >>> - if (test_opt(sbi, DISABLE_CHECKPOINT) &&
> >>> - test_opt(sbi, MERGE_CHECKPOINT)) {
> >>> - f2fs_err(sbi, "checkpoint=merge cannot be used with checkpoint=disable\n");
> >>> - return -EINVAL;
> >>> - }
> >>> -
> >>> /* Not pass down write hints if the number of active logs is lesser
> >>> * than NR_CURSEG_PERSIST_TYPE.
> >>> */
> >>> @@ -1782,7 +1781,7 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
> >>> seq_printf(seq, ",checkpoint=disable:%u",
> >>> F2FS_OPTION(sbi).unusable_cap);
> >>> if (test_opt(sbi, MERGE_CHECKPOINT))
> >>> - seq_puts(seq, ",checkpoint=merge");
> >>> + seq_puts(seq, ",checkpoint_merge");
> >>
> >> Other noxxx options will be shown in show_options(), how about following them?
> >>
> >>> if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_POSIX)
> >>> seq_printf(seq, ",fsync_mode=%s", "posix");
> >>> else if (F2FS_OPTION(sbi).fsync_mode == FSYNC_MODE_STRICT)
> >>> @@ -1827,6 +1826,7 @@ static void default_options(struct f2fs_sb_info *sbi)
> >>> sbi->sb->s_flags |= SB_LAZYTIME;
> >>> set_opt(sbi, FLUSH_MERGE);
> >>> set_opt(sbi, DISCARD);
> >>> + clear_opt(sbi, MERGE_CHECKPOINT);
> >>
> >> Why should we clear checkpoint_merge option in default_options()?
> >>
> >> Thanks,
> >>
> >>> if (f2fs_sb_has_blkzoned(sbi))
> >>> F2FS_OPTION(sbi).fs_mode = FS_MODE_LFS;
> >>> else
> >>> @@ -2066,9 +2066,8 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> >>> }
> >>> }
> >>>
> >>> - if (!test_opt(sbi, MERGE_CHECKPOINT)) {
> >>> - f2fs_stop_ckpt_thread(sbi);
> >>> - } else {
> >>> + if (!test_opt(sbi, DISABLE_CHECKPOINT) &&
> >>> + test_opt(sbi, MERGE_CHECKPOINT)) {
> >>> err = f2fs_start_ckpt_thread(sbi);
> >>> if (err) {
> >>> f2fs_err(sbi,
> >>> @@ -2076,6 +2075,8 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data)
> >>> err);
> >>> goto restore_gc;
> >>> }
> >>> + } else {
> >>> + f2fs_stop_ckpt_thread(sbi);
> >>> }
> >>>
> >>> /*
> >>> @@ -3831,7 +3832,8 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
> >>>
> >>> /* setup checkpoint request control and start checkpoint issue thread */
> >>> f2fs_init_ckpt_req_control(sbi);
> >>> - if (test_opt(sbi, MERGE_CHECKPOINT)) {
> >>> + if (!test_opt(sbi, DISABLE_CHECKPOINT) &&
> >>> + test_opt(sbi, MERGE_CHECKPOINT)) {
> >>> err = f2fs_start_ckpt_thread(sbi);
> >>> if (err) {
> >>> f2fs_err(sbi,
> >>>
> > .
> >