Re: [PATCH v2] f2fs: combine nat_bits and free_nid_bitmap cache

[Chao Yu]

Hi Jaegeuk,

On 2017/3/8 6:27, Jaegeuk Kim wrote:
> Hi Chao,
> 
> There were two reasons for slow down; one is set_bit_le and the other was 
> spin_lock calls.
> 
> I think it would'b good to merge this patch in yours as well.
> Let me know. I'm ready to integrate together and test them.

The change looks good to me. ;)

Anyway I will send last updated patch which you have merged in order to tracking
others' comments if there will be.

Thanks,

> 
> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> ---
>  fs/f2fs/node.c | 22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> index 3377a512e299..0a1ea59c9d31 100644
> --- a/fs/f2fs/node.c
> +++ b/fs/f2fs/node.c
> @@ -1815,7 +1815,7 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
>  }
>  
>  void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
> -							bool set, bool build)
> +			bool set, bool build, bool locked)
>  {
>  	struct f2fs_nm_info *nm_i = NM_I(sbi);
>  	unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
> @@ -1829,12 +1829,14 @@ void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
>  	else
>  		__clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
>  
> -	spin_lock(&nm_i->free_nid_lock);
> +	if (!locked)
> +		spin_lock(&nm_i->free_nid_lock);
>  	if (set)
>  		nm_i->free_nid_count[nat_ofs]++;
>  	else if (!build)
>  		nm_i->free_nid_count[nat_ofs]--;
> -	spin_unlock(&nm_i->free_nid_lock);
> +	if (!locked)
> +		spin_unlock(&nm_i->free_nid_lock);
>  }
>  
>  static void scan_nat_page(struct f2fs_sb_info *sbi,
> @@ -1863,7 +1865,7 @@ static void scan_nat_page(struct f2fs_sb_info *sbi,
>  		f2fs_bug_on(sbi, blk_addr == NEW_ADDR);
>  		if (blk_addr == NULL_ADDR)
>  			freed = add_free_nid(sbi, start_nid, true);
> -		update_free_nid_bitmap(sbi, start_nid, freed, true);
> +		update_free_nid_bitmap(sbi, start_nid, freed, true, false);
>  	}
>  }
>  
> @@ -2018,7 +2020,7 @@ bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
>  		__insert_nid_to_list(sbi, i, ALLOC_NID_LIST, false);
>  		nm_i->available_nids--;
>  
> -		update_free_nid_bitmap(sbi, *nid, false, false);
> +		update_free_nid_bitmap(sbi, *nid, false, false, false);
>  
>  		spin_unlock(&nm_i->nid_list_lock);
>  		return true;
> @@ -2074,7 +2076,7 @@ void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
>  
>  	nm_i->available_nids++;
>  
> -	update_free_nid_bitmap(sbi, nid, true, false);
> +	update_free_nid_bitmap(sbi, nid, true, false, false);
>  
>  	spin_unlock(&nm_i->nid_list_lock);
>  
> @@ -2404,11 +2406,11 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
>  			add_free_nid(sbi, nid, false);
>  			spin_lock(&NM_I(sbi)->nid_list_lock);
>  			NM_I(sbi)->available_nids++;
> -			update_free_nid_bitmap(sbi, nid, true, false);
> +			update_free_nid_bitmap(sbi, nid, true, false, false);
>  			spin_unlock(&NM_I(sbi)->nid_list_lock);
>  		} else {
>  			spin_lock(&NM_I(sbi)->nid_list_lock);
> -			update_free_nid_bitmap(sbi, nid, false, false);
> +			update_free_nid_bitmap(sbi, nid, false, false, false);
>  			spin_unlock(&NM_I(sbi)->nid_list_lock);
>  		}
>  	}
> @@ -2533,8 +2535,10 @@ inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
>  		nid = i * NAT_ENTRY_PER_BLOCK;
>  		last_nid = (i + 1) * NAT_ENTRY_PER_BLOCK;
>  
> +		spin_lock(&nm_i->free_nid_lock);
>  		for (; nid < last_nid; nid++)
> -			update_free_nid_bitmap(sbi, nid, true, true);
> +			update_free_nid_bitmap(sbi, nid, true, true, true);
> +		spin_unlock(&nm_i->free_nid_lock);
>  	}
>  
>  	for (i = 0; i < nm_i->nat_blocks; i++) {
>