From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with SMTP id 3E5558D0040 for ; Thu, 31 Mar 2011 10:26:13 -0400 (EDT) From: "Zhang, Yang Z" Date: Thu, 31 Mar 2011 22:26:05 +0800 Subject: [PATCH 7/7,v10] NUMA Hotplug Emulator: Implement per-node add_memory debugfs interface Message-ID: <749B9D3DBF0F054390025D9EAFF47F224A3D6C45@shsmsx501.ccr.corp.intel.com> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: "akpm@linux-foundation.org" Cc: "linux-mm@kvack.org" , "haicheng.li@linux.intel.com" , "lethal@linux-sh.org" , "Kleen, Andi" , "dave@linux.vnet.ibm.com" , "gregkh@suse.de" , "mingo@elte.hu" , "lenb@kernel.org" , "linux-kernel@vger.kernel.org" , "yinghai@kernel.org" , "Li, Xin" Add add_memory interface to support to memory hotplug emulation for each on= line node under debugfs. The reserved memory can be added into desired node with this interface. The layout on debugfs: node_hotplug/node0/add_memory node_hotplug/node1/add_memory node_hotplug/node2/add_memory ... Add a memory section(128M) to node 3(boots with mem=3D1024m) echo 0x40000000 > node_hotplug/node3/add_memory CC: David Rientjes CC: Dave Hansen Signed-off-by: Haicheng Li Signed-off-by: Shaohui Zheng Signed-off-by: Yang Zhang --- Documentation/memory-hotplug.txt | 24 ++++++++++++ mm/memory_hotplug.c | 77 ++++++++++++++++++++++++++++++++++= ++++ 2 files changed, 101 insertions(+), 0 deletions(-) diff --git a/Documentation/memory-hotplug.txt linux-hpe4/Documentation/memo= ry-hotplug.txt index bc8c99e..9fa8fc7 100644 --- a/Documentation/memory-hotplug.txt +++ linux-hpe4/Documentation/memory-hotplug.txt @@ -19,6 +19,7 @@ be changed often. 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 @@ -254,6 +255,29 @@ Where "size" can be represented in megabytes or gigaby= tes (for example, 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. + +There is an add_memory interface for each online node at the debugfs mount +point. + mem_hotplug/node0/add_memory + mem_hotplug/node1/add_memory + mem_hotplug/node2/add_memory + ... + +Add a memory section(128M) to node 3(boots with mem=3D1024m) + + echo 0x40000000 > mem_hotplug/node3/add_memory + +And more we make it friendly, it is possible to add memory to do + + echo 1024m > mem_hotplug/node3/add_memory + +Once the new memory section has been added, it is possible to online the m= emory +by toggling the "state" described in section 5.1. ------------------------------ 5. Logical Memory hot-add phase diff --git a/mm/memory_hotplug.c linux-hpe4/mm/memory_hotplug.c index f0be4b4..0193e96 100644 --- a/mm/memory_hotplug.c +++ linux-hpe4/mm/memory_hotplug.c @@ -942,6 +942,81 @@ static struct dentry *node_hp_debug_root; extern char *emu_cmdline; extern int emu_nid_to_phys[MAX_NUMNODES]; +#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 =3D 0; + int nid =3D file->private_data - NULL; + int ret; + + printk(KERN_INFO "Add a memory section to node: %d.\n", nid); + phys_addr =3D simple_strtoull(buf, NULL, 0); + + ret =3D add_memory(nid, phys_addr, PAGES_PER_SECTION << PAGE_SHIFT)= ; + if (ret) + count =3D ret; + + return count; +} + +static int add_memory_open(struct inode *inode, struct file *file) +{ + file->private_data =3D inode->i_private; + return 0; +} + +static const struct file_operations add_memory_file_ops =3D { + .open =3D add_memory_open, + .write =3D add_memory_store, + .llseek =3D generic_file_llseek, +}; + +/* + * Create add_memory debugfs entry under specified node + */ +static int debugfs_create_add_memory_entry(int nid) +{ + char buf[32]; + static struct dentry *node_debug_root; + + snprintf(buf, sizeof(buf), "node%d", nid); + node_debug_root =3D debugfs_create_dir(buf, memhp_debug_root); + if (!node_debug_root) + return -ENOMEM; + + /* the nid information was represented by the offset of pointer(NUL= L+nid) */ + if (!debugfs_create_file("add_memory", S_IWUSR, node_debug_root, + NULL + nid, &add_memory_file_ops)) + return -ENOMEM; + + return 0; +} + +static int __init memory_debug_init(void) +{ + int nid; + + if (!memhp_debug_root) + memhp_debug_root =3D debugfs_create_dir("mem_hotplug", NULL= ); + if (!memhp_debug_root) + return -ENOMEM; + + for_each_online_node(nid) + debugfs_create_add_memory_entry(nid); + + return 0; +} + +module_init(memory_debug_init); +#else +static debugfs_create_add_memory_entry(int nid) +{ + return 0; +} +#endif /* CONFIG_ARCH_MEMORY_PROBE */ + static ssize_t add_node_store(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { @@ -973,6 +1048,8 @@ static ssize_t add_node_store(struct file *file, const= char __user *buf, emu_nid_to_phys[nid] =3D nid; ret =3D add_memory(nid, start, size); + + debugfs_create_add_memory_entry(nid); return ret ? ret : count; } -- 1.7.1.1 -- best regards yang -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org