Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753732Ab3H0JkW (ORCPT ); Tue, 27 Aug 2013 05:40:22 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:49294 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753435Ab3H0JjR (ORCPT ); Tue, 27 Aug 2013 05:39:17 -0400 X-IronPort-AV: E=Sophos;i="4.89,967,1367942400"; d="scan'208";a="8317110" From: Tang Chen To: rjw@sisk.pl, lenb@kernel.org, tglx@linutronix.de, mingo@elte.hu, hpa@zytor.com, akpm@linux-foundation.org, tj@kernel.org, trenn@suse.de, yinghai@kernel.org, jiang.liu@huawei.com, wency@cn.fujitsu.com, laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, mgorman@suse.de, minchan@kernel.org, mina86@mina86.com, gong.chen@linux.intel.com, vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com, riel@redhat.com, jweiner@redhat.com, prarit@redhat.com, zhangyanfei@cn.fujitsu.com Cc: x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-acpi@vger.kernel.org Subject: [PATCH 11/11] x86, mem_hotplug: Allocate memory near kernel image before SRAT is parsed. Date: Tue, 27 Aug 2013 17:37:48 +0800 Message-Id: <1377596268-31552-12-git-send-email-tangchen@cn.fujitsu.com> X-Mailer: git-send-email 1.7.11.7 In-Reply-To: <1377596268-31552-1-git-send-email-tangchen@cn.fujitsu.com> References: <1377596268-31552-1-git-send-email-tangchen@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/08/27 17:37:09, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/08/27 17:37:15, Serialize complete at 2013/08/27 17:37:15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2841 Lines: 79 After memblock is ready, before SRAT is parsed, we should allocate memory near the kernel image. So this patch does the following: 1. After memblock is ready, make memblock allocate memory from low address to high, and set the lowest limit to the end of kernel image. 2. After SRAT is parsed, make memblock behave as default, allocate memory from high address to low, and reset the lowest limit to 0. This behavior is controlled by movablenode boot option. Signed-off-by: Tang Chen Reviewed-by: Zhang Yanfei --- arch/x86/kernel/setup.c | 37 +++++++++++++++++++++++++++++++++++++ 1 files changed, 37 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index fa7b5f0..0b35bbd 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -1087,6 +1087,31 @@ void __init setup_arch(char **cmdline_p) trim_platform_memory_ranges(); trim_low_memory_range(); +#ifdef CONFIG_MOVABLE_NODE + if (movablenode_enable_srat) { + /* + * Memory used by the kernel cannot be hot-removed because Linux cannot + * migrate the kernel pages. When memory hotplug is enabled, we should + * prevent memblock from allocating memory for the kernel. + * + * ACPI SRAT records all hotpluggable memory ranges. But before SRAT is + * parsed, we don't know about it. + * + * The kernel image is loaded into memory at very early time. We cannot + * prevent this anyway. So on NUMA system, we set any node the kernel + * resides in as un-hotpluggable. + * + * Since on modern servers, one node could have double-digit gigabytes + * memory, we can assume the memory around the kernel image is also + * un-hotpluggable. So before SRAT is parsed, just allocate memory near + * the kernel image to try the best to keep the kernel away from + * hotpluggable memory. + */ + memblock_set_current_order(MEMBLOCK_ORDER_LOW_TO_HIGH); + memblock_set_current_limit_low(__pa_symbol(_end)); + } +#endif /* CONFIG_MOVABLE_NODE */ + init_mem_mapping(); early_trap_pf_init(); @@ -1127,6 +1152,18 @@ void __init setup_arch(char **cmdline_p) early_acpi_boot_init(); initmem_init(); + +#ifdef CONFIG_MOVABLE_NODE + if (movablenode_enable_srat) { + /* + * When ACPI SRAT is parsed, which is done in initmem_init(), set + * memblock back to the default behavior. + */ + memblock_set_current_order(MEMBLOCK_ORDER_DEFAULT); + memblock_set_current_limit_low(0); + } +#endif /* CONFIG_MOVABLE_NODE */ + memblock_find_dma_reserve(); #ifdef CONFIG_KVM_GUEST -- 1.7.1 -- 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/