[PATCH] mm/hugetlb: avoid weird message in hugetlb_init

[Longpeng(Mike)]

From: Longpeng <longpeng2@xxxxxxxxxx>

Some architectures(e.g. x86,risv) doesn't add 2M-hstate by default,
so if we add 'default_hugepagesz=2M' but without 'hugepagesz=2M' in
cmdline, we'll get a message as follow:
"HugeTLB: unsupported default_hugepagesz 2097152. Reverting to 2097152"

As architecture-specific HPAGE_SIZE hstate should be supported by
default, we can avoid this weird message by add it if we hadn't yet.

Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Qian Cai <cai@xxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Signed-off-by: Longpeng <longpeng2@xxxxxxxxxx>
---
 mm/hugetlb.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index dd8737a..21f623b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2829,6 +2829,9 @@ static int __init hugetlb_init(void)
 	if (!hugepages_supported())
 		return 0;
 
+	if (!size_to_hstate(HPAGE_SIZE))
+		hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
+
 	if (!size_to_hstate(default_hstate_size)) {
 		if (default_hstate_size != 0) {
 			pr_err("HugeTLB: unsupported default_hugepagesz %lu. Reverting to %lu\n",
@@ -2836,8 +2839,6 @@ static int __init hugetlb_init(void)
 		}
 
 		default_hstate_size = HPAGE_SIZE;
-		if (!size_to_hstate(default_hstate_size))
-			hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
 	}
 	default_hstate_idx = hstate_index(size_to_hstate(default_hstate_size));
 	if (default_hstate_max_huge_pages) {
-- 
1.8.3.1