Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752132AbcKGEId (ORCPT ); Sun, 6 Nov 2016 23:08:33 -0500 Received: from mail-pf0-f171.google.com ([209.85.192.171]:35430 "EHLO mail-pf0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751503AbcKGEIc (ORCPT ); Sun, 6 Nov 2016 23:08:32 -0500 Date: Sun, 6 Nov 2016 20:08:29 -0800 (PST) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: Andrew Morton cc: "Kirill A. Shutemov" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, intel-gfx@lists.freedesktop.org Subject: [PATCH] shmem: fix pageflags after swapping DMA32 object Message-ID: User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1262 Lines: 31 If shmem_alloc_page() does not set PageLocked and PageSwapBacked, then shmem_replace_page() needs to do so for itself. Without this, it puts newpage on the wrong lru, re-unlocks the unlocked newpage, and system descends into "Bad page" reports and freeze; or if CONFIG_DEBUG_VM=y, it hits an earlier VM_BUG_ON_PAGE(!PageLocked), depending on config. But shmem_replace_page() is not a common path: it's only called when swapin (or swapoff) finds the page was already read into an unsuitable zone: usually all zones are suitable, but gem objects for a few drm devices (gma500, omapdrm, crestline, broadwater) require zone DMA32 if there's more than 4GB of ram. Fixes: 800d8c63b2e9 ("shmem: add huge pages support") Cc: stable@vger.kernel.org # v4.8 Signed-off-by: Hugh Dickins --- mm/shmem.c | 2 ++ 1 file changed, 2 insertions(+) --- 4.9-rc4/mm/shmem.c 2016-10-15 12:52:13.157533478 -0700 +++ linux/mm/shmem.c 2016-11-06 12:45:49.626193769 -0800 @@ -1483,6 +1483,8 @@ static int shmem_replace_page(struct pag copy_highpage(newpage, oldpage); flush_dcache_page(newpage); + __SetPageLocked(newpage); + __SetPageSwapBacked(newpage); SetPageUptodate(newpage); set_page_private(newpage, swap_index); SetPageSwapCache(newpage);