From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753988AbYKHMtS (ORCPT ); Sat, 8 Nov 2008 07:49:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753228AbYKHMtF (ORCPT ); Sat, 8 Nov 2008 07:49:05 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:40192 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753221AbYKHMtC (ORCPT ); Sat, 8 Nov 2008 07:49:02 -0500 From: "Rafael J. Wysocki" To: Andrew Morton Subject: [PATCH] Fix __pfn_to_page(pfn) for CONFIG_DISCONTIGMEM=y Date: Sat, 8 Nov 2008 13:53:33 +0100 User-Agent: KMail/1.9.9 Cc: Linus Torvalds , LKML , Pavel Machek , pm list MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-2" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200811081353.34442.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Andrew, This would be good to have in .28 IMO. Thanks, Rafael --- From: Rafael J. Wysocki Subject: Fix __pfn_to_page(pfn) for CONFIG_DISCONTIGMEM=y Fix macro __pfn_to_page(pfn) so that it doesn't evaluate its argument twice in the CONFIG_DISCONTIGMEM=y case, because 'pfn' may be a result of a funtion call having side effects. For example, the hibernation code applies pfn_to_page(pfn) to the result of a function returning the pfn corresponding to the next set bit in a bitmap and the current bit position is modified on each call. This leads to "interesting" failures for CONFIG_DISCONTIGMEM=y due to the current behavior of __pfn_to_page(pfn). Signed-off-by: Rafael J. Wysocki Cc: Pavel Machek --- include/asm-generic/memory_model.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-2.6/include/asm-generic/memory_model.h =================================================================== --- linux-2.6.orig/include/asm-generic/memory_model.h +++ linux-2.6/include/asm-generic/memory_model.h @@ -34,7 +34,7 @@ #define __pfn_to_page(pfn) \ ({ unsigned long __pfn = (pfn); \ - unsigned long __nid = arch_pfn_to_nid(pfn); \ + unsigned long __nid = arch_pfn_to_nid(__pfn); \ NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\ })