mm: reclaim for unevictable cma pages [1/1]

PD#SWPL-3902

Problem:
If cma page is unevictable, migrate it will cost long time.

Solution:
1. Recalim unevictable cma file cache pages.
2. Using CMA after first water mark not ok.

Verify:
einstern

Change-Id: I0ecbf5dd535cb034430c4ea623891e7a7ae6e4dd
Signed-off-by: Tao Zeng <tao.zeng@amlogic.com>

drivers/amlogic/memory_ext/aml_cma.c

@@ -101,6 +101,7 @@ EXPORT_SYMBOL(cma_page_count_update);
 
 #define RESTRIC_ANON	0
 #define ANON_RATIO	60
+bool cma_first_wm_low __read_mostly;
 
 bool can_use_cma(gfp_t gfp_flags)
 {
@@ -108,6 +109,9 @@ bool can_use_cma(gfp_t gfp_flags)
 	unsigned long anon_cma;
 #endif /* RESTRIC_ANON */
 
+	if (unlikely(!cma_first_wm_low))
+		return false;
+
 	if (cma_forbidden_mask(gfp_flags))
 		return false;
 
@@ -715,14 +719,17 @@ EXPORT_SYMBOL(aml_cma_free);
 void show_page(struct page *page)
 {
 	unsigned long trace = 0;
+	unsigned long map_flag = -1UL;
 
 	if (!page)
 		return;
 #ifdef CONFIG_AMLOGIC_PAGE_TRACE
 	trace = get_page_trace(page);
 #endif
-	pr_info("page:%lx, map:%p, f:%lx, m:%d, c:%d, f:%pf\n",
-		page_to_pfn(page), page->mapping,
+	if (page->mapping && !((unsigned long)page->mapping & 0x3))
+		map_flag = page->mapping->flags;
+	pr_info("page:%lx, map:%p, mf:%lx, pf:%lx, m:%d, c:%d, f:%pf\n",
+		page_to_pfn(page), page->mapping, map_flag,
 		page->flags & 0xffffffff,
 		page_mapcount(page), page_count(page),
 		(void *)trace);

include/linux/amlogic/aml_cma.h

@@ -74,6 +74,7 @@ extern bool cma_page(struct page *page);
 extern unsigned long get_cma_allocated(void);
 extern unsigned long get_total_cmapages(void);
 extern spinlock_t cma_iso_lock;
+extern bool cma_first_wm_low;
 extern int cma_debug_level;
 extern int aml_cma_alloc_range(unsigned long start, unsigned long end);
 

mm/cma.c

@@ -499,6 +499,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
 	int ret;
 #ifdef CONFIG_AMLOGIC_CMA
 	int dummy;
+	unsigned long long tick;
 #endif /* CONFIG_AMLOGIC_CMA */
 
 	if (!cma || !cma->count)
@@ -508,6 +509,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
 		 count, align);
 
 #ifdef CONFIG_AMLOGIC_CMA
+	tick = sched_clock();
 	cma_debug(0, NULL, "(cma %p, count %zu, align %d)\n",
 		  (void *)cma, count, align);
 #endif
@@ -572,7 +574,8 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align)
 
 #ifdef CONFIG_AMLOGIC_CMA
 	aml_cma_alloc_post_hook(&dummy, count, page);
-	cma_debug(0, NULL, "return %p\n", page);
+	cma_debug(0, NULL, "return page:%lx, tick:%lld\n",
+		  page ? page_to_pfn(page) : 0, sched_clock() - tick);
 #endif /* CONFIG_AMLOGIC_CMA */
 	pr_debug("%s(): returned %p\n", __func__, page);
 	return page;

mm/migrate.c

@@ -445,7 +445,7 @@ int migrate_page_move_mapping(struct address_space *mapping,
 		radix_tree_deref_slot_protected(pslot, &mapping->tree_lock) != page) {
 		spin_unlock_irq(&mapping->tree_lock);
 	#ifdef CONFIG_AMLOGIC_CMA
-		cma_debug(2, page, " anon page cnt miss match, e:%d, p:%d\n",
+		cma_debug(2, page, " file page cnt miss match, e:%d, p:%d\n",
 			  expected_count, page_has_private(page));
 	#endif
 		return -EAGAIN;

mm/page_alloc.c

@@ -3007,8 +3007,21 @@ bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
 	 * are not met, then a high-order request also cannot go ahead
 	 * even if a suitable page happened to be free.
 	 */
+#ifdef CONFIG_AMLOGIC_CMA
+	if (free_pages <= min + z->lowmem_reserve[classzone_idx]) {
+		/* do not using cma until water mark is low */
+		if (unlikely(!cma_first_wm_low && free_pages > 0)) {
+			cma_first_wm_low = true;
+			pr_info("Now can use cma, free:%ld, wm:%ld\n",
+				free_pages,
+				min + z->lowmem_reserve[classzone_idx]);
+		}
+		return false;
+	}
+#else
 	if (free_pages <= min + z->lowmem_reserve[classzone_idx])
 		return false;
+#endif
 
 	/* If this is an order-0 request then the watermark is fine */
 	if (!order)

mm/vmscan.c

@@ -1315,6 +1315,9 @@ static int filecache_need_migrate(struct page *page)
 	if (!PageActive(page) && page_mapcount(page) >= INACTIVE_MIGRATE)
 		return 1;
 
+	if (PageUnevictable(page))
+		return 0;
+
 	return 0;
 }
 #endif