Messages in this thread | | | Date | Wed, 5 May 2021 21:46:21 -0700 | From | Jaegeuk Kim <> | Subject | Re: [PATCH] f2fs: set file as cold when file defragmentation |
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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 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?
> > 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.park@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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