[PATCH v2 18/69] mm/hugetlb: Remove unused bootmem cma field

[Muchun Song]

struct huge_bootmem_page no longer needs to keep the CMA pointer. The
bootmem path only needs to remember whether a huge page came from CMA,
which is already encoded in the flags field.

Set HUGE_BOOTMEM_CMA when the page is allocated and drop the unused cma
field together with the redundant assignments.

Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
---
 include/linux/hugetlb.h |  1 -
 mm/hugetlb.c            |  5 +----
 mm/hugetlb_cma.c        | 27 ++++++++++-----------------
 3 files changed, 11 insertions(+), 22 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index ece4e6a4a4c6..fd901bb3630c 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -694,7 +694,6 @@ struct huge_bootmem_page {
 	struct list_head list;
 	struct hstate *hstate;
 	unsigned long flags;
-	struct cma *cma;
 };
 
 #define HUGE_BOOTMEM_HVO		0x0001
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index dcf8e09ec6be..1f0a0e31d624 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3093,10 +3093,7 @@ static bool __init alloc_bootmem_huge_page(struct hstate *h, int nid)
 	 */
 	INIT_LIST_HEAD(&m->list);
 	m->hstate = h;
-	if (!hugetlb_early_cma(h)) {
-		m->cma = NULL;
-		m->flags = 0;
-	}
+	m->flags = hugetlb_early_cma(h) ? HUGE_BOOTMEM_CMA : 0;
 
 	/* CMA pages: zone-crossing is validated in hugetlb_cma_reserve(). */
 	if (!hugetlb_early_cma(h) &&
diff --git a/mm/hugetlb_cma.c b/mm/hugetlb_cma.c
index 6b5c2aec4449..fbe5ed7ffaa7 100644
--- a/mm/hugetlb_cma.c
+++ b/mm/hugetlb_cma.c
@@ -65,26 +65,19 @@ hugetlb_cma_alloc_bootmem(struct hstate *h, int nid, bool node_exact)
 
 	cma = hugetlb_cma[nid];
 	m = cma_reserve_early(cma, huge_page_size(h));
-	if (!m) {
-		if (node_exact)
-			return NULL;
+	if (m || node_exact)
+		return m;
 
-		for_each_node_mask(node, hugetlb_bootmem_nodes) {
-			cma = hugetlb_cma[node];
-			if (!cma || node == nid)
-				continue;
-			m = cma_reserve_early(cma, huge_page_size(h));
-			if (m)
-				break;
-		}
-	}
-
-	if (m) {
-		m->flags = HUGE_BOOTMEM_CMA;
-		m->cma = cma;
+	for_each_node_mask(node, hugetlb_bootmem_nodes) {
+		cma = hugetlb_cma[node];
+		if (!cma || node == nid)
+			continue;
+		m = cma_reserve_early(cma, huge_page_size(h));
+		if (m)
+			return m;
 	}
 
-	return m;
+	return NULL;
 }
 
 static int __init cmdline_parse_hugetlb_cma(char *p)
-- 
2.54.0