[RFC PATCH] arm64/hugetlb enable gigantic hugepage

[Xie Yisheng]

As we know, arm64 also support gigantic hugepage eg. 1G.
So I try to use this function by adding hugepagesz=1G
in kernel parameters, with CONFIG_CMA=y.
However, when:
echo xx > /sys/kernel/mm/hugepages/hugepages-1048576kB/
          nr_hugepages
it failed with the info:
-bash: echo: write error: Invalid argument

This patch make gigantic hugepage can be used on arm64,
when CONFIG_CMA=y or other related configs is enable.

Signed-off-by: Xie Yisheng <xieyisheng1@xxxxxxxxxx>
---
 mm/hugetlb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 87e11d8..b4d8048 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1022,7 +1022,8 @@ static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed)
 		((node = hstate_next_node_to_free(hs, mask)) || 1);	\
 		nr_nodes--)
 
-#if (defined(CONFIG_X86_64) || defined(CONFIG_S390)) && \
+#if (defined(CONFIG_X86_64) || defined(CONFIG_S390) || \
+	defined(CONFIG_ARM64)) && \
 	((defined(CONFIG_MEMORY_ISOLATION) && defined(CONFIG_COMPACTION)) || \
 	defined(CONFIG_CMA))
 static void destroy_compound_gigantic_page(struct page *page,
-- 
1.7.12.4