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Date: Tue, 30 Apr 2024 16:14:37 +0000
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Message-ID: <20240430161437.2100295-1-fvdl@google.com>
Subject: [PATCH] mm/hugetlb: align cma on allocation order, not demotion order
From: Frank van der Linden <fvdl@google.com>
To: linux-mm@kvack.org, muchun.song@linux.dev, akpm@linux-foundation.org
Cc: linux-kernel@vger.kernel.org, Frank van der Linden <fvdl@google.com>, 
	Roman Gushchin <roman.gushchin@linux.dev>
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Align the CMA area for hugetlb gigantic pages to their size, not the
size that they can be demoted to. Otherwise there might be misaligned
sections at the start and end of the CMA area that will never be used
for hugetlb page allocations.

Signed-off-by: Frank van der Linden <fvdl@google.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Fixes: a01f43901cfb ("hugetlb: be sure to free demoted CMA pages to CMA")
---
 mm/hugetlb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 5dc3f5ea3a2e..cfe7b025c576 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -7794,7 +7794,7 @@ void __init hugetlb_cma_reserve(int order)
 		 * huge page demotion.
 		 */
 		res = cma_declare_contiguous_nid(0, size, 0,
-					PAGE_SIZE << HUGETLB_PAGE_ORDER,
+					PAGE_SIZE << order,
 					HUGETLB_PAGE_ORDER, false, name,
 					&hugetlb_cma[nid], nid);
 		if (res) {
-- 
2.45.0.rc0.197.gbae5840b3b-goog