From b7b229594c13cf682fd1f1f0cde93c3c4573676f Mon Sep 17 00:00:00 2001 From: Chris von Recklinghausen Date: Fri, 20 Oct 2023 06:13:41 -0400 Subject: [PATCH] hugetlb: add comment for subtle SetHPageVmemmapOptimized() JIRA: https://issues.redhat.com/browse/RHEL-1848 commit a9e1eab241bdaadd56b6cfdc481cff6a24c4799b Author: Miaohe Lin Date: Thu Sep 1 20:00:28 2022 +0800 hugetlb: add comment for subtle SetHPageVmemmapOptimized() The SetHPageVmemmapOptimized() called here seems unnecessary as it's assumed to be set when calling this function. But it's indeed cleared by above set_page_private(page, 0). Add a comment to avoid possible future confusion. Link: https://lkml.kernel.org/r/20220901120030.63318-9-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Reviewed-by: Muchun Song Cc: Mike Kravetz Signed-off-by: Andrew Morton Signed-off-by: Chris von Recklinghausen --- mm/hugetlb.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 56e046d36f86..431c2b3b9e27 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1516,6 +1516,10 @@ static void add_hugetlb_page(struct hstate *h, struct page *page, set_compound_page_dtor(page, HUGETLB_PAGE_DTOR); set_page_private(page, 0); + /* + * We have to set HPageVmemmapOptimized again as above + * set_page_private(page, 0) cleared it. + */ SetHPageVmemmapOptimized(page); /*