From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755484Ab3ELB2Z (ORCPT ); Sat, 11 May 2013 21:28:25 -0400 Received: from mga03.intel.com ([143.182.124.21]:3497 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754633Ab3ELBVi (ORCPT ); Sat, 11 May 2013 21:21:38 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,654,1363158000"; d="scan'208";a="332629679" From: "Kirill A. Shutemov" To: Andrea Arcangeli , Andrew Morton Cc: Al Viro , Hugh Dickins , Wu Fengguang , Jan Kara , Mel Gorman , linux-mm@kvack.org, Andi Kleen , Matthew Wilcox , "Kirill A. Shutemov" , Hillf Danton , Dave Hansen , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv4 16/39] thp, mm: locking tail page is a bug Date: Sun, 12 May 2013 04:23:13 +0300 Message-Id: <1368321816-17719-17-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1368321816-17719-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1368321816-17719-1-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 From: "Kirill A. Shutemov" Locking head page means locking entire compound page. If we try to lock tail page, something went wrong. Signed-off-by: Kirill A. Shutemov --- mm/filemap.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/filemap.c b/mm/filemap.c index 3a03426..9ea46a4 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -681,6 +681,7 @@ void __lock_page(struct page *page) { DEFINE_WAIT_BIT(wait, &page->flags, PG_locked); + VM_BUG_ON(PageTail(page)); __wait_on_bit_lock(page_waitqueue(page), &wait, sleep_on_page, TASK_UNINTERRUPTIBLE); } @@ -690,6 +691,7 @@ int __lock_page_killable(struct page *page) { DEFINE_WAIT_BIT(wait, &page->flags, PG_locked); + VM_BUG_ON(PageTail(page)); return __wait_on_bit_lock(page_waitqueue(page), &wait, sleep_on_page_killable, TASK_KILLABLE); } -- 1.7.10.4