Re: [PATCH] f2fs: separate IPU policy for fdatasync from F2FS_IPU_FSYNC

[Chao Yu <chao@kernel.org>]

On 2022/11/2 20:25, qixiaoyu wrote:
> Hi Chao,
> 
> fdatasync do in-place-update to avoid additional node writes, but currently
> it only do that with F2FS_IPU_FSYNC as:
> 
> f2fs_do_sync_file:
> 	if (datasync || get_dirty_pages(inode) <= SM_I(sbi)->min_fsync_blocks)
>   		set_inode_flag(inode, FI_NEED_IPU);
> 
> check_inplace_update_policy:
> 	/* this is only set during fdatasync */
> 	if (policy & (0x1 << F2FS_IPU_FSYNC) &&
> 			is_inode_flag_set(inode, FI_NEED_IPU))
> 		return true;
> 
> So this patch separate in-place-update of fdatasync from F2FS_IPU_FSYNC to
> apply it to all IPU policy.
> 
> BTW, we found small performance improvement with this patch on AndroBench app
> using F2FS_IPU_SSR_UTIL on our product:

How this patch affects performance when F2FS_IPU_SSR_UTIL is on?

Thanks,

> 
>                  F2FS_IPU_FSYNC  F2FS_IPU_SSR_UTIL   F2FS_IPU_SSR_UTIL(with patch)
> SQLite Insert(QPS)  6818.08     6327.09(-7.20%)     6757.72
> SQLite Update(QPS)  6528.81     6336.57(-2.94%)     6490.77
> SQLite Delete(QPS)  9724.68     9378.37(-3.56%)     9622.27
> 
> Thanks
> 
> On Tue, Nov 01, 2022 at 11:14:55PM +0800, Chao Yu wrote:
>> On 2022/10/21 10:31, qixiaoyu1 wrote:
>>> Currently IPU policy for fdatasync is coupled with F2FS_IPU_FSYNC.
>>> Fix to apply it to all IPU policy.
>>
>> Xiaoyu,
>>
>> Sorry for the delay.
>>
>> I didn't get the point, can you please explain more about the
>> issue?
>>
>> Thanks,
>>
>>>
>>> Signed-off-by: qixiaoyu1 <qixiaoyu1@xiaomi.com>
>>> ---
>>>   fs/f2fs/data.c | 8 +++-----
>>>   fs/f2fs/file.c | 4 +++-
>>>   2 files changed, 6 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>>> index a71e818cd67b..fec8e15fe820 100644
>>> --- a/fs/f2fs/data.c
>>> +++ b/fs/f2fs/data.c
>>> @@ -2518,6 +2518,9 @@ static inline bool check_inplace_update_policy(struct inode *inode,
>>>   	if (policy & (0x1 << F2FS_IPU_HONOR_OPU_WRITE) &&
>>>   			is_inode_flag_set(inode, FI_OPU_WRITE))
>>>   		return false;
>>> +	/* this is set by fdatasync or F2FS_IPU_FSYNC policy */
>>> +	if (is_inode_flag_set(inode, FI_NEED_IPU))
>>> +		return true;
>>>   	if (policy & (0x1 << F2FS_IPU_FORCE))
>>>   		return true;
>>>   	if (policy & (0x1 << F2FS_IPU_SSR) && f2fs_need_SSR(sbi))
>>> @@ -2538,11 +2541,6 @@ static inline bool check_inplace_update_policy(struct inode *inode,
>>>   			!IS_ENCRYPTED(inode))
>>>   		return true;
>>> -	/* this is only set during fdatasync */
>>> -	if (policy & (0x1 << F2FS_IPU_FSYNC) &&
>>> -			is_inode_flag_set(inode, FI_NEED_IPU))
>>> -		return true;
>>> -
>>>   	if (unlikely(fio && is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
>>>   			!f2fs_is_checkpointed_data(sbi, fio->old_blkaddr)))
>>>   		return true;
>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>>> index 82cda1258227..08091550cdf2 100644
>>> --- a/fs/f2fs/file.c
>>> +++ b/fs/f2fs/file.c
>>> @@ -270,8 +270,10 @@ static int f2fs_do_sync_file(struct file *file, loff_t start, loff_t end,
>>>   		goto go_write;
>>>   	/* if fdatasync is triggered, let's do in-place-update */
>>> -	if (datasync || get_dirty_pages(inode) <= SM_I(sbi)->min_fsync_blocks)
>>> +	if (datasync || (SM_I(sbi)->ipu_policy & (0x1 << F2FS_IPU_FSYNC) &&
>>> +			get_dirty_pages(inode) <= SM_I(sbi)->min_fsync_blocks))
>>>   		set_inode_flag(inode, FI_NEED_IPU);
>>> +
>>>   	ret = file_write_and_wait_range(file, start, end);
>>>   	clear_inode_flag(inode, FI_NEED_IPU);