From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Capper Subject: [RFC PATCH v2 05/11] mm: thp: Correct the HPAGE_PMD_ORDER check. Date: Wed, 8 May 2013 10:52:37 +0100 Message-ID: <1368006763-30774-6-git-send-email-steve.capper@linaro.org> References: <1368006763-30774-1-git-send-email-steve.capper@linaro.org> Return-path: Received: from mail-wi0-f179.google.com ([209.85.212.179]:56049 "EHLO mail-wi0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753861Ab3EHJxQ (ORCPT ); Wed, 8 May 2013 05:53:16 -0400 Received: by mail-wi0-f179.google.com with SMTP id l13so1700849wie.0 for ; Wed, 08 May 2013 02:53:15 -0700 (PDT) In-Reply-To: <1368006763-30774-1-git-send-email-steve.capper@linaro.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-mm@kvack.org, x86@kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Michal Hocko , Ken Chen , Mel Gorman , Catalin Marinas , Will Deacon , patches@linaro.org, Steve Capper All Transparent Huge Pages are allocated by the buddy allocator. A compile time check is in place that fails when the order of a transparent huge page is too large to be allocated by the buddy allocator. Unfortunately that compile time check passes when: HPAGE_PMD_ORDER == MAX_ORDER ( which is incorrect as the buddy allocator can only allocate memory of order strictly less than MAX_ORDER. ) This patch updates the compile time check to fail in the above case. Signed-off-by: Steve Capper --- include/linux/huge_mm.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index ee1c244..3d71e5c 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -119,7 +119,7 @@ extern void __split_huge_page_pmd(struct vm_area_struct *vma, } while (0) extern void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address, pmd_t *pmd); -#if HPAGE_PMD_ORDER > MAX_ORDER +#if HPAGE_PMD_ORDER >= MAX_ORDER #error "hugepages can't be allocated by the buddy allocator" #endif extern int hugepage_madvise(struct vm_area_struct *vma, -- 1.8.1.4