mm: change lmk/cma using policy [1/1]

PD#TV-10462

Problem:
Memory will allocation fail if play secure vedio source. Usually
seen by zram/wifi driver

Solution:
1, wake up kswapd earlier if water mark without free cma is not ok;
2, using zone-filecache to increace active of lmk. Which can be more
accurate than using global page status;
3, remove some restrict of using cma when allocate movable page by
zram or migrate from cma pool;
4, try allocate hard for atomic request in soft IRQ

Verify:
T950L

Change-Id: Ibf03f3c11a32175e9983ee8a61a14ae4b2436f1e
Signed-off-by: Tao Zeng <tao.zeng@amlogic.com>

drivers/amlogic/memory_ext/aml_cma.c

@@ -117,13 +117,6 @@ bool can_use_cma(gfp_t gfp_flags)
 	if (cma_forbidden_mask(gfp_flags))
 		return false;
 
-	/*
-	 * do not use cma pages when cma allocate is working. this is the
-	 * weakest condition
-	 */
-	if (cma_alloc_ref())
-		return false;
-
 	if (task_nice(current) > 0)
 		return false;
 
@@ -229,7 +222,7 @@ static unsigned long get_align_pfn_high(unsigned long pfn)
 static struct page *get_migrate_page(struct page *page, unsigned long private,
 				  int **resultp)
 {
-	gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_BDEV;
+	gfp_t gfp_mask = GFP_USER | __GFP_MOVABLE;
 	struct page *new = NULL;
 #ifdef CONFIG_AMLOGIC_PAGE_TRACE
 	struct page_trace *old_trace, *new_trace;

drivers/staging/android/lowmemorykiller.c

@@ -139,16 +139,38 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
 	short selected_oom_score_adj;
 	int array_size = ARRAY_SIZE(lowmem_adj);
 	int other_free = global_page_state(NR_FREE_PAGES) - totalreserve_pages;
-	int other_file = global_node_page_state(NR_FILE_PAGES) -
-				global_node_page_state(NR_SHMEM) -
-				global_node_page_state(NR_UNEVICTABLE) -
-				total_swapcache_pages();
 #ifdef CONFIG_AMLOGIC_CMA
+	int other_file;
+	struct zone *z = NULL;
+	pg_data_t *pgdat;
 	int free_cma   = 0;
 	int file_cma   = 0;
 	int cma_forbid = 0;
+	int zfile      = 0;
+	int globle_file = global_node_page_state(NR_FILE_PAGES) -
+			  global_node_page_state(NR_SHMEM) -
+			  global_node_page_state(NR_UNEVICTABLE) -
+			  total_swapcache_pages();
 
-	if (cma_forbidden_mask(sc->gfp_mask) && !current_is_kswapd()) {
+	if (gfp_zone(sc->gfp_mask) == ZONE_NORMAL) {
+		/* using zone page state for more accurate */
+		pgdat = NODE_DATA(sc->nid);
+		z     = &pgdat->node_zones[ZONE_NORMAL];
+		if (managed_zone(z)) {
+			zfile = zone_page_state(z, NR_ZONE_INACTIVE_FILE) +
+				zone_page_state(z, NR_ZONE_ACTIVE_FILE);
+			other_file = zfile -
+				     global_node_page_state(NR_SHMEM) -
+				     zone_page_state(z, NR_ZONE_UNEVICTABLE) -
+				     total_swapcache_pages();
+		} else {
+			other_file = globle_file;
+		}
+	} else {
+		other_file = globle_file;
+	}
+	if (cma_forbidden_mask(sc->gfp_mask) &&
+	    (!current_is_kswapd() || cma_alloc_ref())) {
 		free_cma    = global_page_state(NR_FREE_CMA_PAGES);
 		file_cma    = global_page_state(NR_INACTIVE_FILE_CMA) +
 			      global_page_state(NR_ACTIVE_FILE_CMA);
@@ -156,6 +178,11 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
 		other_file -= file_cma;
 		cma_forbid  = 1;
 	}
+#else
+	int other_file = global_node_page_state(NR_FILE_PAGES) -
+				global_node_page_state(NR_SHMEM) -
+				global_node_page_state(NR_UNEVICTABLE) -
+				total_swapcache_pages();
 #endif /* CONFIG_AMLOGIC_CMA */
 
 	if (lowmem_adj_size < array_size)
@@ -254,6 +281,12 @@ static unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
 		} else {
 			lowmem_deathpending_timeout = jiffies + HZ;
 		}
+		if (z)
+			pr_info("  zone:%s, file:%d, shmem:%ld, unevc:%ld, file_cma:%d\n",
+				z->name, zfile,
+				global_node_page_state(NR_SHMEM),
+				zone_page_state(z, NR_ZONE_UNEVICTABLE),
+				file_cma);
 	#else
 		lowmem_deathpending_timeout = jiffies + HZ;
 	#endif /* CONFIG_AMLOGIC_CMA */

mm/page_alloc.c

@@ -3017,9 +3017,7 @@ bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
 
 #ifdef CONFIG_CMA
 	/* If allocation can't use CMA areas don't use free CMA pages */
-#ifndef CONFIG_AMLOGIC_CMA /* always sub cma pages to avoid wm all CMA */
 	if (!(alloc_flags & ALLOC_CMA))
-#endif
 		free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES);
 #endif
 
@@ -3196,6 +3194,12 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
 			if (alloc_flags & ALLOC_NO_WATERMARKS)
 				goto try_this_zone;
 
+		#ifdef CONFIG_AMLOGIC_MEMORY_EXTEND
+			/* alloc harder if under softirq */
+			if (in_serving_softirq() && (gfp_mask & __GFP_ATOMIC))
+				goto try_this_zone;
+		#endif
+
 			if (node_reclaim_mode == 0 ||
 			    !zone_allows_reclaim(ac->preferred_zoneref->zone, zone))
 				continue;
@@ -4005,15 +4009,22 @@ static inline void should_wakeup_kswap(gfp_t gfp_mask, int order,
 	unsigned long free_pages, free_cma = 0;
 	struct zoneref *z = ac->preferred_zoneref;
 	struct zone *zone;
+	unsigned long high_wm;
 
-	if (!(gfp_mask & __GFP_RECLAIM))	/* not allowed */
+	/*
+	 * 1, if flag not allow reclaim
+	 * 2, if with aotimic, we still need enable pre-wake up of
+	 *    kswap to avoid large amount memory request fail in very
+	 *    short time
+	 */
+	if (!(gfp_mask & __GFP_RECLAIM) && !(gfp_mask & __GFP_ATOMIC))
 		return;
 
 	for_next_zone_zonelist_nodemask(zone, z, ac->zonelist, ac->high_zoneidx,
 								ac->nodemask) {
 		free_pages = zone_page_state(zone, NR_FREE_PAGES);
 	#ifdef CONFIG_AMLOGIC_CMA
-		if (can_use_cma(gfp_mask))
+		if (!can_use_cma(gfp_mask))
 			free_cma = zone_page_state(zone, NR_FREE_CMA_PAGES);
 	#endif /* CONFIG_AMLOGIC_CMA */
 		free_pages -= free_cma;
@@ -4022,7 +4033,10 @@ static inline void should_wakeup_kswap(gfp_t gfp_mask, int order,
 		 * fast reclaim process and can avoid memory become too low
 		 * some times
 		 */
-		if (free_pages <= high_wmark_pages(zone))
+		high_wm = high_wmark_pages(zone);
+		if (gfp_mask & __GFP_HIGH) /* 1.5x if __GFP_HIGH */
+			high_wm = ((high_wm * 3) / 2);
+		if (free_pages <= high_wm)
 			wakeup_kswapd(zone, order, ac->high_zoneidx);
 	}
 }