[PATCH v2] mm/cma: print total and used count in cma_alloc()

[Xiang Gao <gxxa03070307@gmail.com>]

From: gaoxiang17 <gaoxiang17@xiaomi.com>

before:
[   24.407814] cma: cma_alloc(cma (____ptrval____), name: reserved, count 1, align 0)
[   24.413397] cma: cma_alloc(cma (____ptrval____), name: reserved, count 1, align 0)
[   24.415886] cma: cma_alloc(cma (____ptrval____), name: reserved, count 1, align 0)

after:
[   24.069738] cma: cma_alloc(cma (____ptrval____), name: reserved, total pages: 16384, used pages: 64, request pages: 1, align 0)
[   24.075317] cma: cma_alloc(cma (____ptrval____), name: reserved, total pages: 16384, used pages: 65, request pages: 1, align 0)
[   24.078455] cma: cma_alloc(cma (____ptrval____), name: reserved, total pages: 16384, used pages: 66, request pages: 1, align 0)

Signed-off-by: gaoxiang17 <gaoxiang17@xiaomi.com>
---
 mm/cma.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/mm/cma.c b/mm/cma.c
index 2d9fae939283..90b3fdbac19c 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -403,6 +403,17 @@ static void cma_debug_show_areas(struct cma *cma)
 	spin_unlock_irq(&cma->lock);
 }
 
+static unsigned long cma_get_used_pages(struct cma *cma)
+{
+	unsigned long used;
+
+	spin_lock_irq(&cma->lock);
+	used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));
+	spin_unlock_irq(&cma->lock);
+
+	return used << cma->order_per_bit;
+}
+
 static struct page *__cma_alloc(struct cma *cma, unsigned long count,
 				unsigned int align, gfp_t gfp)
 {
@@ -420,8 +431,8 @@ static struct page *__cma_alloc(struct cma *cma, unsigned long count,
 	if (!cma || !cma->count || !cma->bitmap)
 		return page;
 
-	pr_debug("%s(cma %p, name: %s, count %lu, align %d)\n", __func__,
-		(void *)cma, cma->name, count, align);
+	pr_debug("%s(cma %p, name: %s, total pages: %lu, used pages: %lu, request pages: %lu, align %d)\n", __func__,
+		(void *)cma, cma->name, cma->count, cma_get_used_pages(cma), count, align);
 
 	if (!count)
 		return page;
-- 
2.34.1