May I ask why is this disabled by default?
On Thu, Nov 23, 2017 at 10:11 PM, Chao Yu <c...@kernel.org> wrote:
> On 2017/11/22 18:23, Sheng Yong wrote:
>> This patch introduces a sysfs interface readdir_ra to enable/disable
>> readaheading inode block in f2fs_readdir. When readdir_ra is enabled,
>> it improves the performance of "readdir + stat".
>>
>> For 300,000 files:
>> time find /data/test > /dev/null
>> disable readdir_ra: 1m25.69s real 0m01.94s user 0m50.80s system
>> enable readdir_ra: 0m18.55s real 0m00.44s user 0m15.39s system
>>
>> Signed-off-by: Sheng Yong <shengyo...@huawei.com>
>
> Reviewed-by: Chao Yu <yuch...@huawei.com>
>
> Thanks,
>
>> ---
>> Documentation/ABI/testing/sysfs-fs-f2fs | 6 ++++++
>> fs/f2fs/dir.c | 4 ++++
>> fs/f2fs/f2fs.h | 1 +
>> fs/f2fs/sysfs.c | 2 ++
>> 4 files changed, 13 insertions(+)
>>
>> diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs
>> b/Documentation/ABI/testing/sysfs-fs-f2fs
>> index a7799c2fca28..d870b5514d15 100644
>> --- a/Documentation/ABI/testing/sysfs-fs-f2fs
>> +++ b/Documentation/ABI/testing/sysfs-fs-f2fs
>> @@ -186,3 +186,9 @@ Date: August 2017
>> Contact: "Jaegeuk Kim" <jaeg...@kernel.org>
>> Description:
>> Controls sleep time of GC urgent mode
>> +
>> +What: /sys/fs/f2fs/<disk>/readdir_ra
>> +Date: November 2017
>> +Contact: "Sheng Yong" <shengyo...@huawei.com>
>> +Description:
>> + Controls readahead inode block in readdir.
>> diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
>> index 2d98d877c09d..724304dc6143 100644
>> --- a/fs/f2fs/dir.c
>> +++ b/fs/f2fs/dir.c
>> @@ -798,6 +798,7 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct
>> f2fs_dentry_ptr *d,
>> unsigned int bit_pos;
>> struct f2fs_dir_entry *de = NULL;
>> struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
>> + struct f2fs_sb_info *sbi = F2FS_I_SB(d->inode);
>>
>> bit_pos = ((unsigned long)ctx->pos % d->max);
>>
>> @@ -836,6 +837,9 @@ int f2fs_fill_dentries(struct dir_context *ctx, struct
>> f2fs_dentry_ptr *d,
>> le32_to_cpu(de->ino), d_type))
>> return 1;
>>
>> + if (sbi->readdir_ra == 1)
>> + ra_node_page(sbi, le32_to_cpu(de->ino));
>> +
>> bit_pos += GET_DENTRY_SLOTS(le16_to_cpu(de->name_len));
>> ctx->pos = start_pos + bit_pos;
>> }
>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>> index ca6b0c9bc621..a269d795ba7c 100644
>> --- a/fs/f2fs/f2fs.h
>> +++ b/fs/f2fs/f2fs.h
>> @@ -1095,6 +1095,7 @@ struct f2fs_sb_info {
>> int dir_level; /* directory level */
>> int inline_xattr_size; /* inline xattr size */
>> unsigned int trigger_ssr_threshold; /* threshold to trigger ssr */
>> + int readdir_ra; /* readahead inode in readdir
>> */
>>
>> block_t user_block_count; /* # of user blocks */
>> block_t total_valid_block_count; /* # of valid blocks */
>> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
>> index 9835348b6e5d..93c3364250dd 100644
>> --- a/fs/f2fs/sysfs.c
>> +++ b/fs/f2fs/sysfs.c
>> @@ -299,6 +299,7 @@ F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, dir_level,
>> dir_level);
>> F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, cp_interval, interval_time[CP_TIME]);
>> F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, idle_interval,
>> interval_time[REQ_TIME]);
>> F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, iostat_enable, iostat_enable);
>> +F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, readdir_ra, readdir_ra);
>> #ifdef CONFIG_F2FS_FAULT_INJECTION
>> F2FS_RW_ATTR(FAULT_INFO_RATE, f2fs_fault_info, inject_rate, inject_rate);
>> F2FS_RW_ATTR(FAULT_INFO_TYPE, f2fs_fault_info, inject_type, inject_type);
>> @@ -346,6 +347,7 @@ static struct attribute *f2fs_attrs[] = {
>> ATTR_LIST(cp_interval),
>> ATTR_LIST(idle_interval),
>> ATTR_LIST(iostat_enable),
>> + ATTR_LIST(readdir_ra),
>> #ifdef CONFIG_F2FS_FAULT_INJECTION
>> ATTR_LIST(inject_rate),
>> ATTR_LIST(inject_type),
>>
>
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