The previous commit made this refactor possible: 28 insertions and 36
deletions.
Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx>
---
mm/vmscan.c | 64 +++++++++++++++++++++++------------------------------
1 file changed, 28 insertions(+), 36 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 50764b2d462f..a8fd6300fa7e 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -4418,14 +4418,15 @@ static bool try_to_inc_max_seq(struct lruvec *lruvec, unsigned long max_seq,
return true;
}
-static unsigned long get_nr_evictable(struct lruvec *lruvec, unsigned long max_seq,
- unsigned long *min_seq, bool can_swap, bool *need_aging)
+static bool should_run_aging(struct lruvec *lruvec, unsigned long max_seq, unsigned long *min_seq,
+ struct scan_control *sc, bool can_swap, unsigned long *nr_to_scan)
{
int gen, type, zone;
unsigned long old = 0;
unsigned long young = 0;
unsigned long total = 0;
struct lru_gen_struct *lrugen = &lruvec->lrugen;
+ struct mem_cgroup *memcg = lruvec_memcg(lruvec);
for (type = !can_swap; type < ANON_AND_FILE; type++) {
unsigned long seq;
@@ -4441,35 +4442,37 @@ static unsigned long get_nr_evictable(struct lruvec *lruvec, unsigned long max_s
total += size;
if (seq == max_seq)
young += size;
- if (seq + MIN_NR_GENS == max_seq)
+ else if (seq + MIN_NR_GENS == max_seq)
old += size;
}
}
+ /* try to scrape all its memory if this memcg was deleted */
+ *nr_to_scan = mem_cgroup_online(memcg) ? (total >> sc->priority) : total;
+
/*
- * The aging tries to be lazy to reduce the overhead. On the other hand,
- * the eviction stalls when the number of generations reaches
- * MIN_NR_GENS. So ideally, there should be MIN_NR_GENS+1 generations,
- * hence the first two if's.
- *
- * Also it's ideal to spread pages out evenly, meaning 1/(MIN_NR_GENS+1)
+ * The aging tries to be lazy to reduce the overhead, while the eviction
+ * stalls when the number of generations reaches MIN_NR_GENS. Hence, the
+ * ideal number of generations is MIN_NR_GENS+1.
+ */
+ if (min_seq[!can_swap] + MIN_NR_GENS > max_seq)
+ return true;
+ if (min_seq[!can_swap] + MIN_NR_GENS < max_seq)
+ return false;
+
+ /*
+ * It's also ideal to spread pages out evenly, i.e., 1/(MIN_NR_GENS+1)
* of the total number of pages for each generation. A reasonable range
* for this average portion is [1/MIN_NR_GENS, 1/(MIN_NR_GENS+2)]. The
- * eviction cares about the lower bound of cold pages, whereas the aging
- * cares about the upper bound of hot pages.
+ * aging cares about the upper bound of hot pages, while the eviction
+ * cares about the lower bound of cold pages.
*/
- if (min_seq[!can_swap] + MIN_NR_GENS > max_seq)
- *need_aging = true;
- else if (min_seq[!can_swap] + MIN_NR_GENS < max_seq)
- *need_aging = false;
- else if (young * MIN_NR_GENS > total)
- *need_aging = true;
- else if (old * (MIN_NR_GENS + 2) < total)
- *need_aging = true;
- else
- *need_aging = false;
+ if (young * MIN_NR_GENS > total)
+ return true;
+ if (old * (MIN_NR_GENS + 2) < total)
+ return true;
- return total;
+ return false;
}
static bool age_lruvec(struct lruvec *lruvec, struct scan_control *sc, unsigned long min_ttl)
@@ -4488,11 +4491,7 @@ static bool age_lruvec(struct lruvec *lruvec, struct scan_control *sc, unsigned
if (mem_cgroup_below_min(memcg))
return false;
- nr_to_scan = get_nr_evictable(lruvec, max_seq, min_seq, swappiness, &need_aging);
- if (!nr_to_scan)
- return false;
-
- nr_to_scan >>= mem_cgroup_online(memcg) ? sc->priority : 0;
+ need_aging = should_run_aging(lruvec, max_seq, min_seq, sc, swappiness, &nr_to_scan);
if (min_ttl) {
int gen = lru_gen_from_seq(min_seq[LRU_GEN_FILE]);
@@ -4506,7 +4505,7 @@ static bool age_lruvec(struct lruvec *lruvec, struct scan_control *sc, unsigned
return false;
}
- if (nr_to_scan && need_aging)
+ if (need_aging)
try_to_inc_max_seq(lruvec, max_seq, sc, swappiness, false);
return true;
@@ -5054,14 +5053,7 @@ static unsigned long get_nr_to_scan(struct lruvec *lruvec, struct scan_control *
(mem_cgroup_below_low(memcg) && !sc->memcg_low_reclaim))
return 0;
- nr_to_scan = get_nr_evictable(lruvec, max_seq, min_seq, can_swap, need_aging);
- if (!nr_to_scan)
- return 0;
-
- nr_to_scan >>= mem_cgroup_online(memcg) ? sc->priority : 0;
- if (!nr_to_scan)
- return 0;
-
+ *need_aging = should_run_aging(lruvec, max_seq, min_seq, sc, can_swap, &nr_to_scan);
if (!*need_aging)
return nr_to_scan;
--
2.37.3.968.ga6b4b080e4-goog
