From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932415AbcBAN0i (ORCPT ); Mon, 1 Feb 2016 08:26:38 -0500 Received: from mga14.intel.com ([192.55.52.115]:51840 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932171AbcBAN0W (ORCPT ); Mon, 1 Feb 2016 08:26:22 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,380,1449561600"; d="scan'208";a="905839086" From: "Kirill A. Shutemov" To: Andrew Morton , Dmitry Vyukov Cc: Vlastimil Babka , David Rientjes , Naoya Horiguchi , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCH 1/2] mm: fix bogus VM_BUG_ON_PAGE() in isolate_lru_page() Date: Mon, 1 Feb 2016 16:26:08 +0300 Message-Id: <1454333169-121369-2-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.7.0 In-Reply-To: <1454333169-121369-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1454333169-121369-1-git-send-email-kirill.shutemov@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We don't care if there's a tail pages which is not on LRU. We are not going to isolate them anyway. Testcase: #include #include #include #include #include #define SIZE 0x2000 int foo; int main() { int fd; char *p; unsigned long mask = 2; fd = open("/dev/sg0", O_RDWR); p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); /* Faultin pages */ foo = p[0] + p[0x1000]; mbind(p, SIZE, MPOL_BIND, &mask, 4, MPOL_MF_MOVE | MPOL_MF_STRICT); return 0; } MPOL_MF_STRICT makes queue_pages_test_walk() ignore !vma_megratable() and we try to queue such pages for migration. It's good question why we ignore !vma_megratable() for MPOL_MF_STRICT, but it's subject for a separate patch. Signed-off-by: Kirill A. Shutemov Reported-by: Dmitry Vyukov Fixes: bb5b8589767a ("mm: make sure isolate_lru_page() is never called for tail page" --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index eb3dd37ccd7c..492fbe73420b 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1443,7 +1443,7 @@ int isolate_lru_page(struct page *page) int ret = -EBUSY; VM_BUG_ON_PAGE(!page_count(page), page); - VM_BUG_ON_PAGE(PageTail(page), page); + VM_BUG_ON_PAGE(PageLRU(page) && PageTail(page), page); if (PageLRU(page)) { struct zone *zone = page_zone(page); -- 2.7.0