@@ -281,4 +281,7 @@ static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor)
}
#endif /* mul_u64_u32_div */
+#define DIV64_U64_ROUND_UP(ll, d) \
+ ({ u64 _tmp = (d); div64_u64((ll) + _tmp - 1, _tmp); })
+
#endif /* _LINUX_MATH64_H */
@@ -2287,9 +2287,11 @@ static void get_scan_count(struct lruvec *lruvec, struct mem_cgroup *memcg,
/*
* Scan types proportional to swappiness and
* their relative recent reclaim efficiency.
+ * Make sure we don't miss the last page
+ * because of a round-off error.
*/
- scan = div64_u64(scan * fraction[file],
- denominator);
+ scan = DIV64_U64_ROUND_UP(scan * fraction[file],
+ denominator);
break;
case SCAN_FILE:
case SCAN_ANON: