revision 3
preliminary patch to avoid disk thrashing (constant reading) under memory pressure before OOM-killer triggers
more info: https://gist.github.com/constantoverride/84eba764f487049ed642eb2111a20830

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 32699b2..7636498 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -208,7 +208,7 @@ enum lru_list {
 
 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)
 
-#define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)
+#define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_INACTIVE_FILE; lru++)
 
 static inline int is_file_lru(enum lru_list lru)
 {
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 03822f8..1f3ffb5 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2086,9 +2086,9 @@ static unsigned long shrink_list(enum lr
 				 struct scan_control *sc)
 {
 	if (is_active_lru(lru)) {
-		if (inactive_list_is_low(lruvec, is_file_lru(lru),
-					 memcg, sc, true))
-			shrink_active_list(nr_to_scan, lruvec, sc, lru);
+		//if (inactive_list_is_low(lruvec, is_file_lru(lru),
+		//			 memcg, sc, true))
+		//	shrink_active_list(nr_to_scan, lruvec, sc, lru);
 		return 0;
 	}
 
@@ -2234,7 +2234,7 @@ static void get_scan_count(struct lruvec *lruvec, struct mem_cgroup *memcg,
 
 	anon  = lruvec_lru_size(lruvec, LRU_ACTIVE_ANON, MAX_NR_ZONES) +
 		lruvec_lru_size(lruvec, LRU_INACTIVE_ANON, MAX_NR_ZONES);
-	file  = lruvec_lru_size(lruvec, LRU_ACTIVE_FILE, MAX_NR_ZONES) +
+	file  = //lruvec_lru_size(lruvec, LRU_ACTIVE_FILE, MAX_NR_ZONES) +
 		lruvec_lru_size(lruvec, LRU_INACTIVE_FILE, MAX_NR_ZONES);
 
 	spin_lock_irq(&pgdat->lru_lock);
@@ -2345,7 +2345,7 @@ static void shrink_node_memcg(struct pglist_data *pgdat, struct mem_cgroup *memc
 			 sc->priority == DEF_PRIORITY);
 
 	blk_start_plug(&plug);
-	while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] ||
+	while (nr[LRU_INACTIVE_ANON] || //nr[LRU_ACTIVE_FILE] ||
 					nr[LRU_INACTIVE_FILE]) {
 		unsigned long nr_anon, nr_file, percentage;
 		unsigned long nr_scanned;
@@ -2372,7 +2372,8 @@ static void shrink_node_memcg(struct pglist_data *pgdat, struct mem_cgroup *memc
 		 * stop reclaiming one LRU and reduce the amount scanning
 		 * proportional to the original scan target.
 		 */
-		nr_file = nr[LRU_INACTIVE_FILE] + nr[LRU_ACTIVE_FILE];
+		nr_file = nr[LRU_INACTIVE_FILE] //+ nr[LRU_ACTIVE_FILE]
+			;
 		nr_anon = nr[LRU_INACTIVE_ANON] + nr[LRU_ACTIVE_ANON];
 
 		/*
@@ -2391,7 +2392,8 @@ static void shrink_node_memcg(struct pglist_data *pgdat, struct mem_cgroup *memc
 			percentage = nr_anon * 100 / scan_target;
 		} else {
 			unsigned long scan_target = targets[LRU_INACTIVE_FILE] +
-						targets[LRU_ACTIVE_FILE] + 1;
+						//targets[LRU_ACTIVE_FILE] + 
+						1;
 			lru = LRU_FILE;
 			percentage = nr_file * 100 / scan_target;
 		}
@@ -2409,10 +2411,12 @@ static void shrink_node_memcg(struct pgl
 		nr[lru] = targets[lru] * (100 - percentage) / 100;
 		nr[lru] -= min(nr[lru], nr_scanned);
 
+		if (LRU_FILE != lru) { //avoid this block for LRU_ACTIVE_FILE
 		lru += LRU_ACTIVE;
 		nr_scanned = targets[lru] - nr[lru];
 		nr[lru] = targets[lru] * (100 - percentage) / 100;
 		nr[lru] -= min(nr[lru], nr_scanned);
+		}
 
 		scan_adjusted = true;
 	}