Swappiness is determined for each scanned memcg individually in
shrink_zone() and is not a parameter that applies throughout the
reclaim scan. Move it out of struct scan_control to prevent
accidental use of a stale value.
Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
---
mm/vmscan.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index d0bc1a209746..757e2a8dbf58 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -89,9 +89,6 @@ struct scan_control {
/* Scan (total_size >> priority) pages at once */
int priority;
- /* anon vs. file LRUs scanning "ratio" */
- int swappiness;
-
/*
* The memory cgroup that hit its limit and as a result is the
* primary target of this reclaim invocation.
@@ -1868,8 +1865,8 @@ enum scan_balance {
* nr[0] = anon inactive pages to scan; nr[1] = anon active pages to scan
* nr[2] = file inactive pages to scan; nr[3] = file active pages to scan
*/
-static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
- unsigned long *nr)
+static void get_scan_count(struct lruvec *lruvec, int swappiness,
+ struct scan_control *sc, unsigned long *nr)
{
struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat;
u64 fraction[2];
@@ -1912,7 +1909,7 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
* using the memory controller's swap limit feature would be
* too expensive.
*/
- if (!global_reclaim(sc) && !sc->swappiness) {
+ if (!global_reclaim(sc) && !swappiness) {
scan_balance = SCAN_FILE;
goto out;
}
@@ -1922,7 +1919,7 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
* system is close to OOM, scan both anon and file equally
* (unless the swappiness setting disagrees with swapping).
*/
- if (!sc->priority && sc->swappiness) {
+ if (!sc->priority && swappiness) {
scan_balance = SCAN_EQUAL;
goto out;
}
@@ -1965,7 +1962,7 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
* With swappiness at 100, anonymous and file have the same priority.
* This scanning priority is essentially the inverse of IO cost.
*/
- anon_prio = sc->swappiness;
+ anon_prio = swappiness;
file_prio = 200 - anon_prio;
/*
@@ -2055,7 +2052,8 @@ out:
/*
* This is a basic per-zone page freer. Used by both kswapd and direct reclaim.
*/
-static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
+static void shrink_lruvec(struct lruvec *lruvec, int swappiness,
+ struct scan_control *sc)
{
unsigned long nr[NR_LRU_LISTS];
unsigned long targets[NR_LRU_LISTS];
@@ -2066,7 +2064,7 @@ static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
struct blk_plug plug;
bool scan_adjusted;
- get_scan_count(lruvec, sc, nr);
+ get_scan_count(lruvec, swappiness, sc, nr);
/* Record the original scan target for proportional adjustments later */
memcpy(targets, nr, sizeof(nr));
@@ -2263,11 +2261,12 @@ static unsigned long shrink_zone(struct zone *zone, struct scan_control *sc)
memcg = mem_cgroup_iter(root, NULL, &reclaim);
do {
struct lruvec *lruvec;
+ int swappiness;
lruvec = mem_cgroup_zone_lruvec(zone, memcg);
+ swappiness = mem_cgroup_swappiness(memcg);
- sc->swappiness = mem_cgroup_swappiness(memcg);
- shrink_lruvec(lruvec, sc);
+ shrink_lruvec(lruvec, swappiness, sc);
/*
* Direct reclaim and kswapd have to scan all memory
@@ -2714,10 +2713,10 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *memcg,
.may_swap = !noswap,
.order = 0,
.priority = 0,
- .swappiness = mem_cgroup_swappiness(memcg),
.target_mem_cgroup = memcg,
};
struct lruvec *lruvec = mem_cgroup_zone_lruvec(zone, memcg);
+ int swappiness = mem_cgroup_swappiness(memcg);
sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) |
(GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK);
@@ -2733,7 +2732,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *memcg,
* will pick up pages from other mem cgroup's as well. We hack
* the priority and make it zero.
*/
- shrink_lruvec(lruvec, &sc);
+ shrink_lruvec(lruvec, swappiness, &sc);
trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed);
--
2.0.0
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