Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757135AbZGBXWl (ORCPT ); Thu, 2 Jul 2009 19:22:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754893AbZGBXWX (ORCPT ); Thu, 2 Jul 2009 19:22:23 -0400 Received: from h5.dl5rb.org.uk ([81.2.74.5]:58016 "EHLO h5.dl5rb.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751549AbZGBXWW (ORCPT ); Thu, 2 Jul 2009 19:22:22 -0400 Date: Fri, 3 Jul 2009 00:22:05 +0100 From: Ralf Baechle To: Wu Zhangjin Cc: LKML , linux-mips@linux-mips.org, Pavel Machek , Wu Zhangjin Subject: Re: [PATCH] [MIPS] Hibernation: only save pages in system ram Message-ID: <20090702232205.GE14804@linux-mips.org> References: <1246373570-21090-1-git-send-email-wuzhangjin@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1246373570-21090-1-git-send-email-wuzhangjin@gmail.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2812 Lines: 91 On Tue, Jun 30, 2009 at 10:52:50PM +0800, Wu Zhangjin wrote: > From: Wu Zhangjin > > when using hibernation(STD) with CONFIG_FLATMEM in linux-mips-64bit, it > fails for the current mips-specific hibernation implementation save the > pages in all of the memory space(except the nosave section) and make > there will be not enough memory left to the STD task itself, and then > fail. in reality, we only need to save the pages in system rams. > > here is the reason why it fail: > > kernel/power/snapshot.c: > > static void mark_nosave_pages(struct memory_bitmap *bm) > { > ... > if (pfn_valid(pfn)) { > ... > } > } > > arch/mips/include/asm/page.h: > > ... > #ifdef CONFIG_FLATMEM > > #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr) > > #elif defined(CONFIG_SPARSEMEM) > > /* pfn_valid is defined in linux/mmzone.h */ > ... > > we can rewrite pfn_valid(pfn) to fix this problem, but I really do not > want to touch such a widely-used macro, so, I used another solution: > > static struct page *saveable_page(struct zone *zone, unsigned long pfn) > { > ... > if ( .... pfn_is_nosave(pfn) > return NULL; > ... > } > > and pfn_is_nosave is implemented in arch/mips/power/cpu.c, so, hacking > this one is better. No - pfn_valid() is broken, so it should be fixed. Commit 752fbeb2e3555c0d236e992f1195fd7ce30e728d introduced the breakage. It seemed to assume that the valid range for PFNs doesn't start at 0 but some higher number but got that entirely wrong.. #define ARCH_PFN_OFFSET PFN_UP(PHYS_OFFSET) #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr) works nicely when PHYS_OFFSET is 0 - as for most MIPS systems and goes horribly wrong otherwise. So I suggest below patch. Ralf Signed-off-by: Ralf Baechle arch/mips/include/asm/page.h | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/arch/mips/include/asm/page.h b/arch/mips/include/asm/page.h index dc0eaa7..96a14a4 100644 --- a/arch/mips/include/asm/page.h +++ b/arch/mips/include/asm/page.h @@ -165,7 +165,14 @@ typedef struct { unsigned long pgprot; } pgprot_t; #ifdef CONFIG_FLATMEM -#define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr) +#define pfn_valid(pfn) \ +({ \ + unsigned long __pfn = (pfn); \ + /* avoid include hell */ \ + extern unsigned long min_low_pfn; \ + \ + __pfn >= min_low_pfn && __pfn < max_mapnr; \ +}) #elif defined(CONFIG_SPARSEMEM) -- 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/