From mboxrd@z Thu Jan 1 00:00:00 1970 From: punit.agrawal@arm.com (Punit Agrawal) Date: Mon, 22 May 2017 15:39:48 +0100 Subject: [PATCH v3 01/11] arm64: hugetlb: set_huge_pte_at Add WARN_ON on !pte_present In-Reply-To: <20170522143958.12867-1-punit.agrawal@arm.com> References: <20170522143958.12867-1-punit.agrawal@arm.com> Message-ID: <20170522143958.12867-3-punit.agrawal@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Steve Capper This patch adds a WARN_ON to set_huge_pte_at as the accessor assumes that entries to be written down are all present. (There are separate accessors to clear huge ptes). We will need to handle the !pte_present case where memory offlining is used on hugetlb pages. swap and migration entries will be supplied to set_huge_pte_at in this case. Cc: David Woods Signed-off-by: Steve Capper Signed-off-by: Punit Agrawal --- arch/arm64/mm/hugetlbpage.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 425a8fcd3d38..0389e2ed51f1 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -69,6 +69,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, unsigned long pfn; pgprot_t hugeprot; + /* + * Code needs to be expanded to handle huge swap and migration + * entries. Needed for HUGETLB and MEMORY_FAILURE. + */ + WARN_ON(!pte_present(pte)); + if (ncontig == 1) { set_pte_at(mm, addr, ptep, pte); return; -- 2.11.0