Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161553Ab3DEL6Y (ORCPT ); Fri, 5 Apr 2013 07:58:24 -0400 Received: from mga02.intel.com ([134.134.136.20]:57127 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161507Ab3DEL6U (ORCPT ); Fri, 5 Apr 2013 07:58:20 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.87,414,1363158000"; d="scan'208";a="289866895" 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: [PATCHv3, RFC 14/34] thp, mm: locking tail page is a bug Date: Fri, 5 Apr 2013 14:59:38 +0300 Message-Id: <1365163198-29726-15-git-send-email-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1365163198-29726-1-git-send-email-kirill.shutemov@linux.intel.com> References: <1365163198-29726-1-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 Content-Length: 1159 Lines: 38 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 1defa83..7b4736c 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -665,6 +665,7 @@ 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); } @@ -674,6 +675,7 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/