From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754370Ab0JDV7R (ORCPT ); Mon, 4 Oct 2010 17:59:17 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:59944 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751563Ab0JDV7O (ORCPT ); Mon, 4 Oct 2010 17:59:14 -0400 Message-ID: <4CAA4DE2.1020406@kernel.org> Date: Mon, 04 Oct 2010 14:57:54 -0700 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.11) Gecko/20100714 SUSE/3.0.6 Thunderbird/3.0.6 MIME-Version: 1.0 To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Benjamin Herrenschmidt CC: "linux-kernel@vger.kernel.org" , Jeremy Fitzhardinge , Vivek Goyal Subject: [PATCH 2/4] x86, memblock: Fix crashkernel allocation References: <4CAA4BD5.4020505@kernel.org> In-Reply-To: <4CAA4BD5.4020505@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Cai Qian found crashkernel is broken with x86 memblock changes 1. crashkernel=128M@32M always reported that range is used, even first kernel is small no one use that range 2. always get following report when using "kexec -p" Could not find a free area of memory of a000 bytes... locate_hole failed The root cause is that generic memblock_find_in_range() will try to get range from top_down. But crashkernel do need from low and specified range. Let's limit the target range with rash_base + crash_size to make sure that We get range from bottom. -v5: use DEFAULT_BZIMAGE_ADDR_MAX to limit area that could be used by bzImge. also second try for vmlinux or new kexec tools will use bzImage 64bit entry Reported-and-Bisected-by: CAI Qian Signed-off-by: Yinghai Lu --- arch/x86/kernel/setup.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) Index: linux-2.6/arch/x86/kernel/setup.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/setup.c +++ linux-2.6/arch/x86/kernel/setup.c @@ -501,6 +501,7 @@ static inline unsigned long long get_tot return total << PAGE_SHIFT; } +#define DEFAULT_BZIMAGE_ADDR_MAX 0x37FFFFFF static void __init reserve_crashkernel(void) { unsigned long long total_mem; @@ -518,17 +519,28 @@ static void __init reserve_crashkernel(v if (crash_base <= 0) { const unsigned long long alignment = 16<<20; /* 16M */ - crash_base = memblock_find_in_range(alignment, ULONG_MAX, crash_size, - alignment); + /* + * Assume half crash_size is for bzImage + * kexec want bzImage is below DEFAULT_BZIMAGE_ADDR_MAX + */ + crash_base = memblock_find_in_range(alignment, + DEFAULT_BZIMAGE_ADDR_MAX + crash_size/2, + crash_size, alignment); + if (crash_base == MEMBLOCK_ERROR) { - pr_info("crashkernel reservation failed - No suitable area found.\n"); - return; + crash_base = memblock_find_in_range(alignment, + ULONG_MAX, crash_size, alignment); + + if (crash_base == MEMBLOCK_ERROR) { + pr_info("crashkernel reservation failed - No suitable area found.\n"); + return; + } } } else { unsigned long long start; - start = memblock_find_in_range(crash_base, ULONG_MAX, crash_size, - 1<<20); + start = memblock_find_in_range(crash_base, + crash_base + crash_size, crash_size, 1<<20); if (start != crash_base) { pr_info("crashkernel reservation failed - memory is in use.\n"); return;