[PATCH 2/2] mm: hugetlb: Use node interface of cma

[Aslan Bakirov <aslan@fb.com>]

With introduction of numa node interface for CMA, this patch is for using
that interface for allocating memory on numa nodes if NUMA is configured.
This will be more efficient  and cleaner because first, instead of
iterating mem range of each numa node, cma_declare_contigueous_nid()
will do its own address finding if we pass 0 for  both min_pfn and
max_pfn, second, it can also handle caseswhere NUMA is not configured
by passing NUMA_NO_NODE as an argument.

In addition, checking if desired size of memory is available or not,
is happening in cma_declare_contiguous_nid()  because base and
limit will be determined there, since 0(any) for  base and
0(any) for limit is passed as argument to the function.

Signed-off-by: Aslan Bakirov <aslan@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
---
 mm/hugetlb.c | 34 ++++++----------------------------
 1 file changed, 6 insertions(+), 28 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index b9f0c903c4cf..8fbf11de747b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5573,42 +5573,20 @@ void __init hugetlb_cma_reserve(int order)
 
 	reserved = 0;
 	for_each_node_state(nid, N_ONLINE) {
-		unsigned long min_pfn = 0, max_pfn = 0;
 		int res;
-#ifdef CONFIG_NUMA
-		unsigned long start_pfn, end_pfn;
-		int i;
 
-		for_each_mem_pfn_range(i, nid, &start_pfn, &end_pfn, NULL) {
-			if (!min_pfn)
-				min_pfn = start_pfn;
-			max_pfn = end_pfn;
-		}
-#else
-		min_pfn = min_low_pfn;
-		max_pfn = max_low_pfn;
-#endif
 		size = min(per_node, hugetlb_cma_size - reserved);
 		size = round_up(size, PAGE_SIZE << order);
 
-		if (size > ((max_pfn - min_pfn) << PAGE_SHIFT) / 2) {
-			pr_warn("hugetlb_cma: cma_area is too big, please try less than %lu MiB\n",
-				round_down(((max_pfn - min_pfn) << PAGE_SHIFT) *
-					   nr_online_nodes / 2 / SZ_1M,
-					   PAGE_SIZE << order));
-			break;
-		}
-
-		res = cma_declare_contiguous(PFN_PHYS(min_pfn), size,
-					     PFN_PHYS(max_pfn),
+		res = cma_declare_contiguous_nid(0, size,
+					     0,
 					     PAGE_SIZE << order,
 					     0, false,
-					     "hugetlb", &hugetlb_cma[nid]);
+					     "hugetlb", &hugetlb_cma[nid], nid);
+
 		if (res) {
-			phys_addr_t begpa = PFN_PHYS(min_pfn);
-			phys_addr_t endpa = PFN_PHYS(max_pfn);
-			pr_warn("%s: reservation failed: err %d, node %d, [%pap, %pap)\n",
-				__func__, res, nid, &begpa, &endpa);
+			pr_warn("%s: reservation failed: err %d, node %d\n",
+				__func__, res, nid);
 			break;
 		}
 
-- 
2.24.1