From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from rcsinet10.oracle.com ([148.87.113.121]) by bombadil.infradead.org with esmtps (Exim 4.72 #1 (Red Hat Linux)) id 1P07H7-0004hC-CY for kexec@lists.infradead.org; Mon, 27 Sep 2010 06:33:22 +0000 Message-ID: <4CA03A2D.4050503@kernel.org> Date: Sun, 26 Sep 2010 23:31:09 -0700 From: Yinghai Lu MIME-Version: 1.0 Subject: Re: kexec load failure introduced by "x86, memblock: Replace e820_/_early string with memblock_" References: <870873343.2003871285555329846.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> In-Reply-To: <870873343.2003871285555329846.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> 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: caiqian@redhat.com Cc: Ingo Molnar , kexec , "linux-kernel@vger.kernel.org" , "H. Peter Anvin" Please check this one on top of tip or next. Thanks Yinghai [PATCH] x86, memblock: Fix crashkernel allocation Cai Qian found that 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. Reported-and-Bisected-by: CAI Qian Signed-off-by: Yinghai Lu --- arch/x86/kernel/setup.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 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 @@ -516,19 +516,28 @@ static void __init reserve_crashkernel(v /* 0 means: find the address automatically */ if (crash_base <= 0) { + unsigned long long start = 0; const unsigned long long alignment = 16<<20; /* 16M */ - crash_base = memblock_find_in_range(alignment, ULONG_MAX, crash_size, - alignment); - if (crash_base == MEMBLOCK_ERROR) { + crash_base = alignment; + while (crash_base < 0xffffffff) { + start = memblock_find_in_range(crash_base, + crash_base + crash_size, crash_size, alignment); + + if (start == crash_base) + break; + + crash_base += alignment; + } + if (start != crash_base) { 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; _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec