Re: [f2fs-dev] [PATCH 04/10] f2fs: give an option to enable in-place-updates during fsync to users

[Jaegeuk Kim]

On Mon, Sep 15, 2014 at 11:13:15AM +0900, Changman Lee wrote:
> Hi JK,
> 
> I think it' nicer if this can be used as 'OR' with other policy
> together. If so, we can also cover the weakness in high utilization.

Agreed.
I'll send another patch for that.
Thanks,

> 
> Regard,
> Changman
> 
> On Sun, Sep 14, 2014 at 03:14:18PM -0700, Jaegeuk Kim wrote:
> > If user wrote F2FS_IPU_FSYNC:4 in /sys/fs/f2fs/ipu_policy, f2fs_sync_file
> > only starts to try in-place-updates.
> > And, if the number of dirty pages is over /sys/fs/f2fs/min_fsync_blocks, it
> > keeps out-of-order manner. Otherwise, it triggers in-place-updates.
> > 
> > This may be used by storage showing very high random write performance.
> > 
> > For example, it can be used when,
> > 
> > Seq. writes (Data) + wait + Seq. writes (Node)
> > 
> > is pretty much slower than,
> > 
> > Rand. writes (Data)
> > 
> > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> > ---
> >  Documentation/ABI/testing/sysfs-fs-f2fs |  7 +++++++
> >  Documentation/filesystems/f2fs.txt      |  9 ++++++++-
> >  fs/f2fs/f2fs.h                          |  1 +
> >  fs/f2fs/file.c                          |  7 +++----
> >  fs/f2fs/segment.c                       |  3 ++-
> >  fs/f2fs/segment.h                       | 14 ++++++++++----
> >  fs/f2fs/super.c                         |  2 ++
> >  7 files changed, 33 insertions(+), 10 deletions(-)
> > 
> > diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
> > index 62dd725..6f9157f 100644
> > --- a/Documentation/ABI/testing/sysfs-fs-f2fs
> > +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
> > @@ -44,6 +44,13 @@ Description:
> >  		 Controls the FS utilization condition for the in-place-update
> >  		 policies.
> >  
> > +What:		/sys/fs/f2fs/<disk>/min_fsync_blocks
> > +Date:		September 2014
> > +Contact:	"Jaegeuk Kim" <jaegeuk@xxxxxxxxxx>
> > +Description:
> > +		 Controls the dirty page count condition for the in-place-update
> > +		 policies.
> > +
> >  What:		/sys/fs/f2fs/<disk>/max_small_discards
> >  Date:		November 2013
> >  Contact:	"Jaegeuk Kim" <jaegeuk.kim@xxxxxxxxxxx>
> > diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
> > index a2046a7..d010da8 100644
> > --- a/Documentation/filesystems/f2fs.txt
> > +++ b/Documentation/filesystems/f2fs.txt
> > @@ -194,13 +194,20 @@ Files in /sys/fs/f2fs/<devname>
> >                                updates in f2fs. There are five policies:
> >                                 0: F2FS_IPU_FORCE, 1: F2FS_IPU_SSR,
> >                                 2: F2FS_IPU_UTIL,  3: F2FS_IPU_SSR_UTIL,
> > -                               4: F2FS_IPU_DISABLE.
> > +                               4: F2FS_IPU_FSYNC, 5: F2FS_IPU_DISABLE.
> >  
> >   min_ipu_util                 This parameter controls the threshold to trigger
> >                                in-place-updates. The number indicates percentage
> >                                of the filesystem utilization, and used by
> >                                F2FS_IPU_UTIL and F2FS_IPU_SSR_UTIL policies.
> >  
> > + min_fsync_blocks             This parameter controls the threshold to trigger
> > +                              in-place-updates when F2FS_IPU_FSYNC mode is set.
> > +			      The number indicates the number of dirty pages
> > +			      when fsync needs to flush on its call path. If
> > +			      the number is less than this value, it triggers
> > +			      in-place-updates.
> > +
> >   max_victim_search	      This parameter controls the number of trials to
> >  			      find a victim segment when conducting SSR and
> >  			      cleaning operations. The default value is 4096
> > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> > index 2756c16..4f84d2a 100644
> > --- a/fs/f2fs/f2fs.h
> > +++ b/fs/f2fs/f2fs.h
> > @@ -386,6 +386,7 @@ struct f2fs_sm_info {
> >  
> >  	unsigned int ipu_policy;	/* in-place-update policy */
> >  	unsigned int min_ipu_util;	/* in-place-update threshold */
> > +	unsigned int min_fsync_blocks;	/* threshold for fsync */
> >  
> >  	/* for flush command control */
> >  	struct flush_cmd_control *cmd_control_info;
> > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> > index 77426c7..af06e22 100644
> > --- a/fs/f2fs/file.c
> > +++ b/fs/f2fs/file.c
> > @@ -154,12 +154,11 @@ int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
> >  	trace_f2fs_sync_file_enter(inode);
> >  
> >  	/* if fdatasync is triggered, let's do in-place-update */
> > -	if (datasync)
> > +	if (get_dirty_pages(inode) <= SM_I(sbi)->min_fsync_blocks)
> >  		set_inode_flag(fi, FI_NEED_IPU);
> > -
> >  	ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
> > -	if (datasync)
> > -		clear_inode_flag(fi, FI_NEED_IPU);
> > +	clear_inode_flag(fi, FI_NEED_IPU);
> > +
> >  	if (ret) {
> >  		trace_f2fs_sync_file_exit(inode, need_cp, datasync, ret);
> >  		return ret;
> > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> > index e158d63..c6f627b 100644
> > --- a/fs/f2fs/segment.c
> > +++ b/fs/f2fs/segment.c
> > @@ -1928,8 +1928,9 @@ int build_segment_manager(struct f2fs_sb_info *sbi)
> >  	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
> >  	sm_info->rec_prefree_segments = sm_info->main_segments *
> >  					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
> > -	sm_info->ipu_policy = F2FS_IPU_DISABLE;
> > +	sm_info->ipu_policy = F2FS_IPU_FSYNC;
> >  	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
> > +	sm_info->min_fsync_blocks = DEF_MIN_FSYNC_BLOCKS;
> >  
> >  	INIT_LIST_HEAD(&sm_info->discard_list);
> >  	sm_info->nr_discards = 0;
> > diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
> > index bed0dc9..013aed2 100644
> > --- a/fs/f2fs/segment.h
> > +++ b/fs/f2fs/segment.h
> > @@ -472,15 +472,20 @@ static inline int utilization(struct f2fs_sb_info *sbi)
> >   * F2FS_IPU_UTIL - if FS utilization is over threashold,
> >   * F2FS_IPU_SSR_UTIL - if SSR mode is activated and FS utilization is over
> >   *                     threashold,
> > + * F2FS_IPU_FSYNC - activated in fsync path only for high performance flash
> > + *                     storages. IPU will be triggered only if the # of dirty
> > + *                     pages over min_fsync_blocks.
> >   * F2FS_IPUT_DISABLE - disable IPU. (=default option)
> >   */
> >  #define DEF_MIN_IPU_UTIL	70
> > +#define DEF_MIN_FSYNC_BLOCKS	8
> >  
> >  enum {
> >  	F2FS_IPU_FORCE,
> >  	F2FS_IPU_SSR,
> >  	F2FS_IPU_UTIL,
> >  	F2FS_IPU_SSR_UTIL,
> > +	F2FS_IPU_FSYNC,
> >  	F2FS_IPU_DISABLE,
> >  };
> >  
> > @@ -492,10 +497,6 @@ static inline bool need_inplace_update(struct inode *inode)
> >  	if (S_ISDIR(inode->i_mode))
> >  		return false;
> >  
> > -	/* this is only set during fdatasync */
> > -	if (is_inode_flag_set(F2FS_I(inode), FI_NEED_IPU))
> > -		return true;
> > -
> >  	switch (SM_I(sbi)->ipu_policy) {
> >  	case F2FS_IPU_FORCE:
> >  		return true;
> > @@ -511,6 +512,11 @@ static inline bool need_inplace_update(struct inode *inode)
> >  		if (need_SSR(sbi) && utilization(sbi) > SM_I(sbi)->min_ipu_util)
> >  			return true;
> >  		break;
> > +	case F2FS_IPU_FSYNC:
> > +		/* this is only set during fdatasync */
> > +		if (is_inode_flag_set(F2FS_I(inode), FI_NEED_IPU))
> > +			return true;
> > +		break;
> >  	case F2FS_IPU_DISABLE:
> >  		break;
> >  	}
> > diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> > index b5af9be..ed4095e 100644
> > --- a/fs/f2fs/super.c
> > +++ b/fs/f2fs/super.c
> > @@ -190,6 +190,7 @@ F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, reclaim_segments, rec_prefree_segments);
> >  F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, max_small_discards, max_discards);
> >  F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, ipu_policy, ipu_policy);
> >  F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_ipu_util, min_ipu_util);
> > +F2FS_RW_ATTR(SM_INFO, f2fs_sm_info, min_fsync_blocks, min_fsync_blocks);
> >  F2FS_RW_ATTR(NM_INFO, f2fs_nm_info, ram_thresh, ram_thresh);
> >  F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, max_victim_search, max_victim_search);
> >  F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level, dir_level);
> > @@ -204,6 +205,7 @@ static struct attribute *f2fs_attrs[] = {
> >  	ATTR_LIST(max_small_discards),
> >  	ATTR_LIST(ipu_policy),
> >  	ATTR_LIST(min_ipu_util),
> > +	ATTR_LIST(min_fsync_blocks),
> >  	ATTR_LIST(max_victim_search),
> >  	ATTR_LIST(dir_level),
> >  	ATTR_LIST(ram_thresh),
> > -- 
> > 1.8.5.2 (Apple Git-48)
> > 
> > 
> > ------------------------------------------------------------------------------
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