Messages in this thread Patch in this message | | | Date | Wed, 1 Jul 2020 09:19:27 -0700 | From | Jaegeuk Kim <> | Subject | Re: [PATCH RFC 2/5] f2fs: record average update time of segment |
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On 06/30, Chao Yu wrote: > Previously, once we update one block in segment, we will update mtime of > segment to last time, making aged segment becoming freshest, result in > that GC with cost benefit algorithm missing such segment, So this patch > changes to record mtime as average block updating time instead of last > updating time. > > It's not needed to reset mtime for prefree segment, as se->valid_blocks > is zero, then old se->mtime won't take any weight with below calculation: > > se->mtime = (se->mtime * se->valid_blocks + mtime) / > (se->valid_blocks + 1); > > Signed-off-by: Chao Yu <yuchao0@huawei.com> > --- > fs/f2fs/segment.c | 21 ++++++++++++++++++--- > 1 file changed, 18 insertions(+), 3 deletions(-) > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 863ec6f1fb87..906c313835ad 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -2150,6 +2150,22 @@ static void __set_sit_entry_type(struct f2fs_sb_info *sbi, int type, > __mark_sit_entry_dirty(sbi, segno); > } > > +static void update_segment_mtime(struct f2fs_sb_info *sbi, block_t blkaddr) > +{ > + unsigned int segno = GET_SEGNO(sbi, blkaddr); > + struct seg_entry *se = get_seg_entry(sbi, segno); > + unsigned long long mtime = get_mtime(sbi, false); > + > + if (!se->mtime) {
Don't need {}.
> + se->mtime = mtime; > + } else { > + se->mtime = (se->mtime * se->valid_blocks + mtime) / > + (se->valid_blocks + 1); > + } > + if (mtime > SIT_I(sbi)->max_mtime) > + SIT_I(sbi)->max_mtime = mtime; > +} > + > static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del) > { > struct seg_entry *se; > @@ -2169,10 +2185,9 @@ static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del) > f2fs_bug_on(sbi, (new_vblocks >> (sizeof(unsigned short) << 3) || > (new_vblocks > sbi->blocks_per_seg))); > > + update_segment_mtime(sbi, blkaddr); > + > se->valid_blocks = new_vblocks; > - se->mtime = get_mtime(sbi, false); > - if (se->mtime > SIT_I(sbi)->max_mtime) > - SIT_I(sbi)->max_mtime = se->mtime; > > /* Update valid block bitmap */ > if (del > 0) { > -- > 2.26.2
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