Messages in this thread | | | Date | Wed, 9 Nov 2022 21:39:58 +0800 | Subject | Re: [PATCH] f2fs: separate IPU policy for fdatasync from F2FS_IPU_FSYNC | From | Chao Yu <> |
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On 2022/11/9 20:56, qixiaoyu wrote: > On Tue, Nov 08, 2022 at 10:30:13PM +0800, Chao Yu wrote: >> On 2022/11/8 20:32, qixiaoyu wrote: >>> On Sun, Nov 06, 2022 at 09:54:59PM +0800, Chao Yu wrote: >>>> 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, >>>> >>> >>> SQLite test in AndroBench app use fdatasync to sync file to the disk. >>> When switch to F2FS_IPU_SSR_UTIL ipu_policy, it will use out-of-place-update >>> even though SQLite calls fdatasync, which will introduce extra meta data write. >> >> Why not using F2FS_IPU_SSR_UTIL | F2FS_IPU_FSYNC, I guess these two flags >> cover different scenarios, F2FS_IPU_SSR_UTIL for ssr case, and F2FS_IPU_FSYNC >> for f{data,}sync case. >> >> Thanks, >> > > As fsync(2) says: > fdatasync() is similar to fsync(), but does not flush modified metadata unless that > metadata is needed in order to allow a subsequent data retrieval to be correctly handled.
I guess it says it allows fdatasync to flush metatdata in order to recovery data in SPO case.
> > I think fdatasync should try to perform in-place-update to avoid unnecessary metadata > update whatever the ipu_policy is, and F2FS_IPU_FSYNC is used for fsync independently.
IMO, FSYNC key word in F2FS_IPU_FSYNC means fsync path or interface name as below:
int (*fsync) (struct file *, loff_t, loff_t, int datasync);
And by default, f2fs enables F2FS_IPU_FSYNC, I didn't get why we need to disable it.
To Jaegeuk, any comments?
Thanks,
> > Thanks > >>> >>> 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);
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