Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757349Ab0LBGhd (ORCPT ); Thu, 2 Dec 2010 01:37:33 -0500 Received: from mga11.intel.com ([192.55.52.93]:31365 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757301Ab0LBGhV (ORCPT ); Thu, 2 Dec 2010 01:37:21 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.59,286,1288594800"; d="scan'208";a="632287535" X-Mailbox-Line: From shaohui.zheng@intel.com Thu Dec 2 13:07:37 2010 Message-Id: <20101202050737.651398415@intel.com> References: <20101202050518.819599911@intel.com> User-Agent: quilt/0.46-1 Date: Thu, 02 Dec 2010 13:05:25 +0800 From: shaohui.zheng@intel.com To: akpm@linux-foundation.org, linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, haicheng.li@linux.intel.com, lethal@linux-sh.org, ak@linux.intel.com, shaohui.zheng@linux.intel.com, rientjes@google.com, dave@linux.vnet.ibm.com, gregkh@suse.de, Shaohui Zheng , Haicheng Li Subject: [patch 7/7, v7] NUMA Hotplug Emulator: Implement mem_hotplug/add_memory debugfs interface Content-Disposition: inline; filename=007-hotplug-emulator-add-memory-debugfs-interface.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5220 Lines: 172 From: Shaohui Zheng Add mem_hotplug/add_memory interface to support to memory hotplug emulation. the reserved memory can be added into desired node with this interface. Add a memory section(128M) to node 3(boots with mem=1024m) echo 0x40000000,3 > mem_hotplug/add_memory And more we make it friendly, it is possible to add memory to do echo 3g > mem_hotplug/add_memory echo 1024m,3 > mem_hotplug/add_memory Another format suggested by Dave Hansen: echo physical_address=0x40000000 numa_node=3 > mem_hotplug/add_memory it is more explicit to show meaning of the parameters. CC: David Rientjes CC: Dave Hansen Signed-off-by: Shaohui Zheng Signed-off-by: Haicheng Li Signed-off-by: Shaohui Zheng --- Index: linux-hpe4/mm/memory_hotplug.c =================================================================== --- linux-hpe4.orig/mm/memory_hotplug.c 2010-12-02 12:17:58.267622002 +0800 +++ linux-hpe4/mm/memory_hotplug.c 2010-12-02 12:18:02.507622002 +0800 @@ -983,4 +983,87 @@ } module_init(node_debug_init); + +#ifdef CONFIG_ARCH_MEMORY_PROBE + +static ssize_t add_memory_store(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + u64 phys_addr = 0; + int nid = 0; + int ret; + char *p = NULL, *q = NULL; + /* format: physical_address=0x40000000 numa_node=3 */ + p = strchr(buf, '='); + if (p != NULL) { + *p = '\0'; + q = strchr(buf, ' '); + if (q == NULL) { + if (strcmp(buf, "physical_address") != 0) + ret = -EPERM; + else + phys_addr = memparse(p+1, NULL); + } else { + *q++ = '\0'; + p = strchr(q, '='); + if (strcmp(buf, "physical_address") == 0) + phys_addr = memparse(p+1, NULL); + if (strcmp(buf, "numa_node") == 0) + nid = simple_strtoul(p+1, NULL, 0); + if (strcmp(q, "physical_address") == 0) + phys_addr = memparse(p+1, NULL); + if (strcmp(q, "numa_node") == 0) + nid = simple_strtoul(p+1, NULL, 0); + } + } else { /* physical_address,numa_node */ + p = strchr(buf, ','); + if (p != NULL && strlen(p+1) > 0) { + /* nid specified */ + *p++ = '\0'; + nid = simple_strtoul(p, NULL, 0); + phys_addr = memparse(buf, NULL); + } else { + phys_addr = memparse(buf, NULL); + nid = memory_add_physaddr_to_nid(phys_addr); + } + } + + if (nid < 0 || nid > nr_node_ids - 1) { + printk(KERN_ERR "Invalid node id %d(0<=nid<%d).\n", nid, nr_node_ids); + ret = -EPERM; + } else { + printk(KERN_INFO "Add a memory section to node: %d.\n", nid); + ret = add_memory(nid, phys_addr, PAGES_PER_SECTION << PAGE_SHIFT); + if (ret) + count = ret; + } + + if (ret) + count = ret; + + return count; +} + +static const struct file_operations add_memory_file_ops = { + .write = add_memory_store, + .llseek = generic_file_llseek, +}; + +static int __init memory_debug_init(void) +{ + if (!memhp_debug_root) + memhp_debug_root = debugfs_create_dir("mem_hotplug", NULL); + if (!memhp_debug_root) + return -ENOMEM; + + if (!debugfs_create_file("add_memory", S_IWUSR, memhp_debug_root, + NULL, &add_memory_file_ops)) + return -ENOMEM; + + return 0; +} + +module_init(memory_debug_init); + +#endif /* CONFIG_ARCH_MEMORY_PROBE */ #endif /* CONFIG_DEBUG_FS */ Index: linux-hpe4/Documentation/memory-hotplug.txt =================================================================== --- linux-hpe4.orig/Documentation/memory-hotplug.txt 2010-12-02 12:18:17.387622002 +0800 +++ linux-hpe4/Documentation/memory-hotplug.txt 2010-12-02 12:30:51.717622000 +0800 @@ -19,6 +19,7 @@ 4.1 Hardware(Firmware) Support 4.2 Notify memory hot-add event by hand 4.3 Node hotplug emulation + 4.4 Memory hotplug emulation 5. Logical Memory hot-add phase 5.1. State of memory 5.2. How to online memory @@ -239,6 +240,30 @@ Once the new node has been added, it is possible to online the memory by toggling the "state" of its memory section(s) as described in section 5.1. +4.4 Memory hotplug emulation +------------ +With debugfs, it is possible to test memory hotplug with software method, we +can add memory section to desired node with add_memory interface. It is a much +more powerful interface than "probe" described in section 4.2. + +The add_memory interface is located at "mem_hotplug/add_memory" at the debugfs +mount point. + +Add a memory section(128M) to node 3(boots with mem=1024m) + + echo 0x40000000,3 > mem_hotplug/add_memory + +And more we make it friendly, it is possible to add memory to do + + echo 3g > mem_hotplug/add_memory + echo 1024m,3 > mem_hotplug/add_memory + +Another format suggested by Dave Hansen: + + echo physical_address=0x40000000 numa_node=3 > mem_hotplug/add_memory + +Once the new memory section has been added, it is possible to online the memory +by toggling the "state" described in section 5.1. ------------------------------ 5. Logical Memory hot-add phase -- Thanks & Regards, Shaohui -- 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/