Currently we wrongly calculate the new block age to
old * LAST_AGE_WEIGHT / 100.
Fix it to new * (100 - LAST_AGE_WEIGHT) / 100
+ old * LAST_AGE_WEIGHT / 100.
Signed-off-by: qixiaoyu1 <[email protected]>
Signed-off-by: xiongping1 <[email protected]>
---
Change log v1 -> v2:
- fix udiv
Change log v2 -> v3:
- keep the accuracy with div_u64_rem
fs/f2fs/extent_cache.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index 342af24b2f8c..d9f12f404beb 100644
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -874,11 +874,18 @@ void f2fs_update_read_extent_tree_range_compressed(struct
inode *inode,
static unsigned long long __calculate_block_age(unsigned long long new,
unsigned long long old)
{
- unsigned long long diff;
+ unsigned int rem_old, rem_new;
+ unsigned long long res;
- diff = (new >= old) ? new - (new - old) : new + (old - new);
+ res = div_u64_rem(new, 100, &rem_new) * (100 - LAST_AGE_WEIGHT)
+ + div_u64_rem(old, 100, &rem_old) * LAST_AGE_WEIGHT;
- return div_u64(diff * LAST_AGE_WEIGHT, 100);
+ if (rem_new)
+ res += rem_new * (100 - LAST_AGE_WEIGHT) / 100;
+ if (rem_old)
+ res += rem_old * LAST_AGE_WEIGHT / 100;
+
+ return res;
}
/* This returns a new age and allocated blocks in ei */
--
2.39.0
_______________________________________________
Linux-f2fs-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
