>On 2021/5/11 13:09, Jaegeuk Kim wrote:
>> On 05/11, Chao Yu wrote:
>>> On 2021/5/10 22:47, Jaegeuk Kim wrote:
>>>> On 05/06, Chao Yu wrote:
>>>>> On 2021/5/6 12:46, Jaegeuk Kim wrote:
>>>>>> On 05/06, Chao Yu wrote:
>>>>>>> On 2021/4/29 14:20, Daejun Park wrote:
>>>>>>>> In file defragmentation by ioctl, all data blocks in the file are
>>>>>>>> re-written out-of-place. File defragmentation implies user will not
>>>>>>>> update
>>>>>>>> and mostly read the file. So before the defragmentation, we set file
>>>>>>>> temperature as cold for better block allocation.
>>>>>>>
>>>>>>> I don't think all fragmented files are cold, e.g. db file.
>>>>>>
>>>>>> I have a bit different opinion. I think one example would be users want
>>>>>> to
>>>>>> defragment a file, when the they want to get higher read bandwidth for
>>>>>
>>>>> Multimedia file was already defined as cold file now via default extension
>>>>> list?
>>>>
>>>> I just gave an example. And default is default.
>>>>
>>>>>
>>>>>> usually multimedia files. That's likely to be cold files. Moreover, I
>>>>>> don't
>>>>>> think they want to defragment db files which will be fragmented soon?
>>>>>
>>>>> I guess like db files have less update but more access?
>>>>
>>>> I think both, and we set it as hot.
>>>
>>> Then hot and cold bit will set to the same db file after defragmentation?
>>
>> Do you set cold bit to db files? I mean, generally db is not cold, but hot.
>
>I never set cold bit to db files, I mean if we defragment db file which
>has less update and more access, db file may have bot hot and cold bit.
>
>To Daejun, may I ask that is Samsung planning to use this defragment ioctl
>in products? what's the user scenario?
It is just my idea for defragmentation, not Samsung.
I think the user will call the defrag ioctl for the files that have been
updated.
On the other hand, I think FS should be able to support defrag file even
when in-place update is applied. What do you think?
Thanks,
Daejun
>
>Thanks,
>
>>
>>>
>>> Thanks,
>>>
>>>>
>>>>>
>>>>> Thanks,
>>>>>
>>>>>>
>>>>>>>
>>>>>>> We have separated interface (via f2fs_xattr_advise_handler, e.g.
>>>>>>> setfattr -n
>>>>>>> "system.advise" -v value) to indicate this file is a hot/cold file, so
>>>>>>> my
>>>>>>> suggestion is after file defragmentation, if you think this file is
>>>>>>> cold, and
>>>>>>> use setxattr() to set it as cold.
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>>>
>>>>>>>> Signed-off-by: Daejun Park <daejun7.p...@samsung.com>
>>>>>>>> ---
>>>>>>>> fs/f2fs/file.c | 3 +++
>>>>>>>> 1 file changed, 3 insertions(+)
>>>>>>>>
>>>>>>>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>>>>>>>> index d697c8900fa7..dcac965a05fe 100644
>>>>>>>> --- a/fs/f2fs/file.c
>>>>>>>> +++ b/fs/f2fs/file.c
>>>>>>>> @@ -2669,6 +2669,9 @@ static int f2fs_defragment_range(struct
>>>>>>>> f2fs_sb_info *sbi,
>>>>>>>> map.m_len = pg_end - pg_start;
>>>>>>>> total = 0;
>>>>>>>> + if (!file_is_cold(inode))
>>>>>>>> + file_set_cold(inode);
>>>>>>>> +
>>>>>>>> while (map.m_lblk < pg_end) {
>>>>>>>> pgoff_t idx;
>>>>>>>> int cnt = 0;
>>>>>>>>
>>>>>> .
>>>>>>
>>>> .
>>>>
>> .
>>
>
>
>
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