Re: [f2fs-dev] [PATCH 3/5] f2fs: control the memory footprint used by ino entries

[Changman Lee <cm224.lee@samsung.com>]

On Sat, Nov 08, 2014 at 11:36:07PM -0800, Jaegeuk Kim wrote:
> This patch adds to control the memory footprint used by ino entries.
> This will conduct best effort, not strictly.
> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
> ---
>  fs/f2fs/node.c    | 28 ++++++++++++++++++++++------
>  fs/f2fs/node.h    |  3 ++-
>  fs/f2fs/segment.c |  3 ++-
>  3 files changed, 26 insertions(+), 8 deletions(-)
> 
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index 44b8afe..4ea2c47 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -31,22 +31,38 @@ bool available_free_memory(struct f2fs_sb_info *sbi, int type)
>  {
>  	struct f2fs_nm_info *nm_i = NM_I(sbi);
>  	struct sysinfo val;
> +	unsigned long avail_ram;
>  	unsigned long mem_size = 0;
>  	bool res = false;
>  
>  	si_meminfo(&val);
> -	/* give 25%, 25%, 50% memory for each components respectively */
> +
> +	/* only uses low memory */
> +	avail_ram = val.totalram - val.totalhigh;
> +
> +	/* give 25%, 25%, 50%, 50% memory for each components respectively */

Hi Jaegeuk,

The memory usage of nm_i should be 100% but it's 125%.
Mistake or intended?

>  	if (type == FREE_NIDS) {
> -		mem_size = (nm_i->fcnt * sizeof(struct free_nid)) >> 12;
> -		res = mem_size < ((val.totalram * nm_i->ram_thresh / 100) >> 2);
> +		mem_size = (nm_i->fcnt * sizeof(struct free_nid)) >>
> +							PAGE_CACHE_SHIFT;
> +		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
>  	} else if (type == NAT_ENTRIES) {
> -		mem_size = (nm_i->nat_cnt * sizeof(struct nat_entry)) >> 12;
> -		res = mem_size < ((val.totalram * nm_i->ram_thresh / 100) >> 2);
> +		mem_size = (nm_i->nat_cnt * sizeof(struct nat_entry)) >>
> +							PAGE_CACHE_SHIFT;
> +		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
>  	} else if (type == DIRTY_DENTS) {
>  		if (sbi->sb->s_bdi->dirty_exceeded)
>  			return false;
>  		mem_size = get_pages(sbi, F2FS_DIRTY_DENTS);
> -		res = mem_size < ((val.totalram * nm_i->ram_thresh / 100) >> 1);
> +		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
> +	} else if (type == INO_ENTRIES) {
> +		int i;
> +
> +		if (sbi->sb->s_bdi->dirty_exceeded)
> +			return false;
> +		for (i = 0; i <= UPDATE_INO; i++)
> +			mem_size += (sbi->ino_num[i] * sizeof(struct ino_entry))
> +							>> PAGE_CACHE_SHIFT;
> +		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
>  	}
>  	return res;
>  }
> diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
> index acb71e5..d10b644 100644
> --- a/fs/f2fs/node.h
> +++ b/fs/f2fs/node.h
> @@ -106,7 +106,8 @@ static inline void raw_nat_from_node_info(struct f2fs_nat_entry *raw_ne,
>  enum mem_type {
>  	FREE_NIDS,	/* indicates the free nid list */
>  	NAT_ENTRIES,	/* indicates the cached nat entry */
> -	DIRTY_DENTS	/* indicates dirty dentry pages */
> +	DIRTY_DENTS,	/* indicates dirty dentry pages */
> +	INO_ENTRIES,	/* indicates inode entries */
>  };
>  
>  struct nat_entry_set {
> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
> index 16721b5d..e094675 100644
> --- a/fs/f2fs/segment.c
> +++ b/fs/f2fs/segment.c
> @@ -276,7 +276,8 @@ void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
>  {
>  	/* check the # of cached NAT entries and prefree segments */
>  	if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK) ||
> -				excess_prefree_segs(sbi))
> +			excess_prefree_segs(sbi) ||
> +			available_free_memory(sbi, INO_ENTRIES))
>  		f2fs_sync_fs(sbi->sb, true);
>  }
>  
> -- 
> 2.1.1
> 
> 
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