[PATCH v6 6/6] mm/cma: remove per zone CMA stat

[js1304]

From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

Now, all reserved pages for CMA region are belong to the ZONE_CMA
so we don't need to maintain CMA stat in other zones. Remove it.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
 fs/proc/meminfo.c      |  2 +-
 include/linux/cma.h    |  6 ++++++
 include/linux/mmzone.h |  1 -
 mm/cma.c               | 15 +++++++++++++++
 mm/page_alloc.c        |  7 +++----
 mm/vmstat.c            |  1 -
 6 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 8a42849..0ca6f38 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -151,7 +151,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
 #ifdef CONFIG_CMA
 	show_val_kb(m, "CmaTotal:       ", totalcma_pages);
 	show_val_kb(m, "CmaFree:        ",
-		    global_page_state(NR_FREE_CMA_PAGES));
+		    cma_get_free());
 #endif
 
 	hugetlb_report_meminfo(m);
diff --git a/include/linux/cma.h b/include/linux/cma.h
index 29f9e77..816290c 100644
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -28,4 +28,10 @@ extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
 					struct cma **res_cma);
 extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align);
 extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count);
+
+#ifdef CONFIG_CMA
+extern unsigned long cma_get_free(void);
+#else
+static inline unsigned long cma_get_free(void) { return 0; }
+#endif
 #endif
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index dd37da9..f5cd27a4 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -113,7 +113,6 @@ enum zone_stat_item {
 	NUMA_LOCAL,		/* allocation from local node */
 	NUMA_OTHER,		/* allocation from other node */
 #endif
-	NR_FREE_CMA_PAGES,
 	NR_VM_ZONE_STAT_ITEMS };
 
 enum node_stat_item {
diff --git a/mm/cma.c b/mm/cma.c
index adc2785..cd869d7 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -54,6 +54,21 @@ unsigned long cma_get_size(const struct cma *cma)
 	return cma->count << PAGE_SHIFT;
 }
 
+unsigned long cma_get_free(void)
+{
+	struct zone *zone;
+	unsigned long freecma = 0;
+
+	for_each_populated_zone(zone) {
+		if (!is_zone_cma(zone))
+			continue;
+
+		freecma += zone_page_state(zone, NR_FREE_PAGES);
+	}
+
+	return freecma;
+}
+
 static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
 					     int align_order)
 {
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6df8533..45a35de 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -65,6 +65,7 @@
 #include <linux/kthread.h>
 #include <linux/memcontrol.h>
 #include <linux/random.h>
+#include <linux/cma.h>
 
 #include <asm/sections.h>
 #include <asm/tlbflush.h>
@@ -4268,7 +4269,7 @@ void show_free_areas(unsigned int filter)
 		global_page_state(NR_BOUNCE),
 		global_page_state(NR_FREE_PAGES),
 		free_pcp,
-		global_page_state(NR_FREE_CMA_PAGES));
+		cma_get_free());
 
 	for_each_online_pgdat(pgdat) {
 		printk("Node %d"
@@ -4349,7 +4350,6 @@ void show_free_areas(unsigned int filter)
 			" bounce:%lukB"
 			" free_pcp:%lukB"
 			" local_pcp:%ukB"
-			" free_cma:%lukB"
 			"\n",
 			zone->name,
 			K(zone_page_state(zone, NR_FREE_PAGES)),
@@ -4371,8 +4371,7 @@ void show_free_areas(unsigned int filter)
 			K(zone_page_state(zone, NR_PAGETABLE)),
 			K(zone_page_state(zone, NR_BOUNCE)),
 			K(free_pcp),
-			K(this_cpu_read(zone->pageset->pcp.count)),
-			K(zone_page_state(zone, NR_FREE_CMA_PAGES)));
+			K(this_cpu_read(zone->pageset->pcp.count)));
 		printk("lowmem_reserve[]:");
 		for (i = 0; i < MAX_NR_ZONES; i++)
 			printk(" %ld", zone->lowmem_reserve[i]);
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 429742f..c1ead13 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -951,7 +951,6 @@ int fragmentation_index(struct zone *zone, unsigned int order)
 	"numa_local",
 	"numa_other",
 #endif
-	"nr_free_cma",
 
 	/* Node-based counters */
 	"nr_inactive_anon",
-- 
1.9.1