From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757546Ab3J1WQU (ORCPT ); Mon, 28 Oct 2013 18:16:20 -0400 Received: from mga14.intel.com ([143.182.124.37]:10335 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751992Ab3J1WQT (ORCPT ); Mon, 28 Oct 2013 18:16:19 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,535,1378882800"; d="scan'208";a="381361072" Subject: [PATCH 1/2] mm: hugetlbfs: Add some VM_BUG_ON()s to catch non-hugetlbfs pages To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, dave.jiang@intel.com, Mel Gorman , akpm@linux-foundation.org, dhillf@gmail.com, Dave Hansen From: Dave Hansen Date: Mon, 28 Oct 2013 15:16:18 -0700 Message-Id: <20131028221618.4078637F@viggo.jf.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dave Jiang reported that he was seeing oopses when running NUMA systems and default_hugepagesz=1G. I traced the issue down to migrate_page_copy() trying to use the same code for hugetlb pages and transparent hugepages. It should not have been trying to pass thp pages in there. So, add some VM_BUG_ON()s for the next hapless VM developer that tries the same thing. --- linux.git-davehans/include/linux/hugetlb.h | 1 + linux.git-davehans/mm/hugetlb.c | 1 + 2 files changed, 2 insertions(+) diff -puN include/linux/hugetlb.h~bug-not-hugetlbfs-in-copy_huge_page include/linux/hugetlb.h --- linux.git/include/linux/hugetlb.h~bug-not-hugetlbfs-in-copy_huge_page 2013-10-28 15:06:12.888828815 -0700 +++ linux.git-davehans/include/linux/hugetlb.h 2013-10-28 15:06:12.893829038 -0700 @@ -355,6 +355,7 @@ static inline pte_t arch_make_huge_pte(p static inline struct hstate *page_hstate(struct page *page) { + VM_BUG_ON(!PageHuge(page)); return size_to_hstate(PAGE_SIZE << compound_order(page)); } diff -puN mm/hugetlb.c~bug-not-hugetlbfs-in-copy_huge_page mm/hugetlb.c --- linux.git/mm/hugetlb.c~bug-not-hugetlbfs-in-copy_huge_page 2013-10-28 15:06:12.890828904 -0700 +++ linux.git-davehans/mm/hugetlb.c 2013-10-28 15:06:12.894829082 -0700 @@ -498,6 +498,7 @@ void copy_huge_page(struct page *dst, st int i; struct hstate *h = page_hstate(src); + VM_BUG_ON(!h); if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) { copy_gigantic_page(dst, src); return; _