From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1TZE4A-0006DX-Im for kexec@lists.infradead.org; Fri, 16 Nov 2012 05:02:11 +0000 Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 1CAFC3EE0AE for ; Fri, 16 Nov 2012 14:02:09 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id EB7AA45DE53 for ; Fri, 16 Nov 2012 14:02:08 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id AC8BE45DE52 for ; Fri, 16 Nov 2012 14:02:08 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id A09061DB803B for ; Fri, 16 Nov 2012 14:02:08 +0900 (JST) Received: from m1000.s.css.fujitsu.com (m1000.s.css.fujitsu.com [10.240.81.136]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 30D3B1DB802F for ; Fri, 16 Nov 2012 14:02:08 +0900 (JST) From: HATAYAMA Daisuke Subject: [PATCH v2 07/10] Add page_is_buddy for recent kernels Date: Fri, 16 Nov 2012 14:02:07 +0900 Message-ID: <20121116050207.8280.14374.stgit@localhost6.localdomain6> In-Reply-To: <20121116050108.8280.14861.stgit@localhost6.localdomain6> References: <20121116050108.8280.14861.stgit@localhost6.localdomain6> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: kumagai-atsushi@mxc.nes.nec.co.jp Cc: kexec@lists.infradead.org On kernels from v2.6.38 and later kernels, buddy page is marked by _mapcount == PAGE_BUDDY_MAPCOUNT_VALUE, which varies once as follows: kernel version | PAGE_BUDDY_MAPCOUNT_VALUE ------------------+-------------------------- v2.6.38 | -2 v2.6.39 and later | -128 One more notice is that _mapcount shares its memory with other fields for SLAB/SLUB when PG_slab is set. Before looking up _mapcount value, we need to check if PG_slab is set. Since this page_is_buddy needs _mapcount, we use freelist logic if _mapcount is not available. Recall that PG_slab has been 7 since v2.6.15. No need to check it. Signed-off-by: HATAYAMA Daisuke --- makedumpfile.c | 21 +++++++++++++++++++++ 1 files changed, 21 insertions(+), 0 deletions(-) diff --git a/makedumpfile.c b/makedumpfile.c index 0e44a8b..7b13dca 100644 --- a/makedumpfile.c +++ b/makedumpfile.c @@ -3668,12 +3668,33 @@ exclude_free_page(void) return TRUE; } +/* + * For v2.6.38 and later kernel versions. + */ +static int +page_is_buddy_v3(unsigned long flags, unsigned int _mapcount, + unsigned long private, unsigned int _count) +{ + if (flags & (1UL << NUMBER(PG_slab))) + return FALSE; + + if (_mapcount == (int)NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE)) + return TRUE; + + return FALSE; +} + static void setup_page_is_buddy(void) { if (OFFSET(page.private) == NOT_FOUND_STRUCTURE) goto out; + if (NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE) != NOT_FOUND_NUMBER) { + if (OFFSET(page._mapcount) != NOT_FOUND_STRUCTURE) + info->page_is_buddy = page_is_buddy_v3; + } + out: if (!info->page_is_buddy) DEBUG_MSG("Can't select page_is_buddy handler; " _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec