From: David Rientjes <[email protected]>
Add an interface to allow new nodes to be added when performing memory
hot-add. This provides a convenient interface to test memory hotplug
notifier callbacks and surrounding hotplug code when new nodes are
onlined without actually having a machine with such hotpluggable SRAT
entries.
This adds a new debugfs interface at /sys/kernel/debug/mem_hotplug/add_node
that behaves in a similar way to the memory hot-add "probe" interface.
Its format is size@start, where "size" is the size of the new node to be
added and "start" is the physical address of the new memory.
The new node id is a currently offline, but possible, node. The bit must
be set in node_possible_map so that nr_node_ids is sized appropriately.
For emulation on x86, for example, it would be possible to set aside
memory for hotplugged nodes (say, anything above 2G) and to add an
additional four nodes as being possible on boot with
mem=2G numa=possible=4
and then creating a new 128M node at runtime:
# echo 128M@0x80000000 > /sys/kernel/debug/mem_hotplug/add_node
On node 1 totalpages: 0
init_memory_mapping: 0000000080000000-0000000088000000
0080000000 - 0088000000 page 2M
Once the new node has been added, its memory can be onlined. If this
memory represents memory section 16, for example:
# echo online > /sys/devices/system/memory/memory16/state
Built 2 zonelists in Node order, mobility grouping on. Total pages: 514846
Policy zone: Normal
[ The memory section(s) mapped to a particular node are visible via
/sys/kernel/debug/mem_hotplug/node1, in this example. ]
The new node is now hotplugged and ready for testing.
CC: Haicheng Li <[email protected]>
CC: Greg KH <[email protected]>
Signed-off-by: David Rientjes <[email protected]>
Signed-off-by: Shaohui Zheng <[email protected]>
---
Documentation/memory-hotplug.txt | 24 +++++++++++++++
mm/memory_hotplug.c | 59 ++++++++++++++++++++++++++++++++++++++
2 files changed, 83 insertions(+), 0 deletions(-)
Index: linux-hpe4/Documentation/memory-hotplug.txt
===================================================================
--- linux-hpe4.orig/Documentation/memory-hotplug.txt 2010-11-30 12:40:43.527622001 +0800
+++ linux-hpe4/Documentation/memory-hotplug.txt 2010-11-30 14:11:11.827622000 +0800
@@ -18,6 +18,7 @@
4. Physical memory hot-add phase
4.1 Hardware(Firmware) Support
4.2 Notify memory hot-add event by hand
+ 4.3 Node hotplug emulation
5. Logical Memory hot-add phase
5.1. State of memory
5.2. How to online memory
@@ -215,6 +216,29 @@
Please see "How to online memory" in this text.
+4.3 Node hotplug emulation
+------------
+With debugfs, it is possible to test node hotplug by assigning the newly
+added memory to a new node id when using a different interface with a similar
+behavior to "probe" described in section 4.2. If a node id is possible
+(there are bits in /sys/devices/system/memory/possible that are not online),
+then it may be used to emulate a newly added node as the result of memory
+hotplug by using the debugfs "add_node" interface.
+
+The add_node interface is located at "mem_hotplug/add_node" at the debugfs
+mount point.
+
+You can create a new node of a specified size starting at the physical
+address of new memory by
+
+% echo size@start_address_of_new_memory > /sys/kernel/debug/mem_hotplug/add_node
+
+Where "size" can be represented in megabytes or gigabytes (for example,
+"128M" or "1G"). The minumum size is that of a memory section.
+
+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.
+
------------------------------
5. Logical Memory hot-add phase
Index: linux-hpe4/mm/memory_hotplug.c
===================================================================
--- linux-hpe4.orig/mm/memory_hotplug.c 2010-11-30 12:40:43.757622001 +0800
+++ linux-hpe4/mm/memory_hotplug.c 2010-11-30 14:02:33.877622002 +0800
@@ -924,3 +924,63 @@
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
EXPORT_SYMBOL_GPL(remove_memory);
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+
+static struct dentry *memhp_debug_root;
+
+static ssize_t add_node_store(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ nodemask_t mask;
+ u64 start, size;
+ char buffer[64];
+ char *p;
+ int nid;
+ int ret;
+
+ memset(buffer, 0, sizeof(buffer));
+ if (count > sizeof(buffer) - 1)
+ count = sizeof(buffer) - 1;
+ if (copy_from_user(buffer, buf, count))
+ return -EFAULT;
+
+ size = memparse(buffer, &p);
+ if (size < (PAGES_PER_SECTION << PAGE_SHIFT))
+ return -EINVAL;
+ if (*p != '@')
+ return -EINVAL;
+
+ start = simple_strtoull(p + 1, NULL, 0);
+
+ nodes_andnot(mask, node_possible_map, node_online_map);
+ nid = first_node(mask);
+ if (nid == MAX_NUMNODES)
+ return -ENOMEM;
+
+ ret = add_memory(nid, start, size);
+ return ret ? ret : count;
+}
+
+static const struct file_operations add_node_file_ops = {
+ .write = add_node_store,
+ .llseek = generic_file_llseek,
+};
+
+static int __init node_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_node", S_IWUSR, memhp_debug_root,
+ NULL, &add_node_file_ops))
+ return -ENOMEM;
+
+ return 0;
+}
+
+module_init(node_debug_init);
+#endif /* CONFIG_DEBUG_FS */
--
Thanks & Regards,
Shaohui
On Fri, 10 Dec 2010 15:31:22 +0800
[email protected] wrote:
> From: David Rientjes <[email protected]>
>
> Add an interface to allow new nodes to be added when performing memory
> hot-add. This provides a convenient interface to test memory hotplug
> notifier callbacks and surrounding hotplug code when new nodes are
> onlined without actually having a machine with such hotpluggable SRAT
> entries.
>
> This adds a new debugfs interface at /sys/kernel/debug/mem_hotplug/add_node
> that behaves in a similar way to the memory hot-add "probe" interface.
> Its format is size@start, where "size" is the size of the new node to be
> added and "start" is the physical address of the new memory.
>
> The new node id is a currently offline, but possible, node. The bit must
> be set in node_possible_map so that nr_node_ids is sized appropriately.
>
> For emulation on x86, for example, it would be possible to set aside
> memory for hotplugged nodes (say, anything above 2G) and to add an
> additional four nodes as being possible on boot with
>
> mem=2G numa=possible=4
>
> and then creating a new 128M node at runtime:
>
> # echo 128M@0x80000000 > /sys/kernel/debug/mem_hotplug/add_node
> On node 1 totalpages: 0
> init_memory_mapping: 0000000080000000-0000000088000000
> 0080000000 - 0088000000 page 2M
> Once the new node has been added, its memory can be onlined. If this
> memory represents memory section 16, for example:
>
> # echo online > /sys/devices/system/memory/memory16/state
> Built 2 zonelists in Node order, mobility grouping on. Total pages: 514846
> Policy zone: Normal
> [ The memory section(s) mapped to a particular node are visible via
> /sys/kernel/debug/mem_hotplug/node1, in this example. ]
>
> The new node is now hotplugged and ready for testing.
>
> CC: Haicheng Li <[email protected]>
> CC: Greg KH <[email protected]>
> Signed-off-by: David Rientjes <[email protected]>
> Signed-off-by: Shaohui Zheng <[email protected]>
> ---
> Documentation/memory-hotplug.txt | 24 +++++++++++++++
> mm/memory_hotplug.c | 59 ++++++++++++++++++++++++++++++++++++++
> 2 files changed, 83 insertions(+), 0 deletions(-)
> Index: linux-hpe4/Documentation/memory-hotplug.txt
> ===================================================================
> --- linux-hpe4.orig/Documentation/memory-hotplug.txt 2010-11-30 12:40:43.527622001 +0800
> +++ linux-hpe4/Documentation/memory-hotplug.txt 2010-11-30 14:11:11.827622000 +0800
> @@ -18,6 +18,7 @@
> 4. Physical memory hot-add phase
> 4.1 Hardware(Firmware) Support
> 4.2 Notify memory hot-add event by hand
> + 4.3 Node hotplug emulation
> 5. Logical Memory hot-add phase
> 5.1. State of memory
> 5.2. How to online memory
> @@ -215,6 +216,29 @@
> Please see "How to online memory" in this text.
>
>
> +4.3 Node hotplug emulation
> +------------
> +With debugfs, it is possible to test node hotplug by assigning the newly
> +added memory to a new node id when using a different interface with a similar
> +behavior to "probe" described in section 4.2. If a node id is possible
> +(there are bits in /sys/devices/system/memory/possible that are not online),
> +then it may be used to emulate a newly added node as the result of memory
> +hotplug by using the debugfs "add_node" interface.
> +
> +The add_node interface is located at "mem_hotplug/add_node" at the debugfs
> +mount point.
> +
> +You can create a new node of a specified size starting at the physical
> +address of new memory by
> +
> +% echo size@start_address_of_new_memory > /sys/kernel/debug/mem_hotplug/add_node
> +
> +Where "size" can be represented in megabytes or gigabytes (for example,
> +"128M" or "1G"). The minumum size is that of a memory section.
> +
> +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.
> +
>
> ------------------------------
> 5. Logical Memory hot-add phase
> Index: linux-hpe4/mm/memory_hotplug.c
> ===================================================================
> --- linux-hpe4.orig/mm/memory_hotplug.c 2010-11-30 12:40:43.757622001 +0800
> +++ linux-hpe4/mm/memory_hotplug.c 2010-11-30 14:02:33.877622002 +0800
> @@ -924,3 +924,63 @@
> }
> #endif /* CONFIG_MEMORY_HOTREMOVE */
> EXPORT_SYMBOL_GPL(remove_memory);
> +
> +#ifdef CONFIG_DEBUG_FS
> +#include <linux/debugfs.h>
> +
> +static struct dentry *memhp_debug_root;
> +
> +static ssize_t add_node_store(struct file *file, const char __user *buf,
> + size_t count, loff_t *ppos)
> +{
> + nodemask_t mask;
NODEMASK_ALLOC()?
> + u64 start, size;
> + char buffer[64];
> + char *p;
> + int nid;
> + int ret;
> +
> + memset(buffer, 0, sizeof(buffer));
> + if (count > sizeof(buffer) - 1)
> + count = sizeof(buffer) - 1;
This will cause the write to return a smaller number than `count': a
short write. Some userspace code may then decide to write the
remainder of the data (whcih is the correct way to use the write()
syscall).
Could be a bit dangerous, and perhaps simply declaring an error if too
much data was written would be a better approach.
> + if (copy_from_user(buffer, buf, count))
> + return -EFAULT;
> +
> + size = memparse(buffer, &p);
> + if (size < (PAGES_PER_SECTION << PAGE_SHIFT))
PAGES_PER_SECTION has type unsigned long, so the rhs of this comparison
might overflow on 32-bit, should anyone ever try to use this code on
32-bit.
otoh the compiler might do it as 64-bit because the lhs is 64-bit. Not
sure.
> + return -EINVAL;
> + if (*p != '@')
> + return -EINVAL;
> +
> + start = simple_strtoull(p + 1, NULL, 0);
You disagreed with checkpatch?
> + nodes_andnot(mask, node_possible_map, node_online_map);
> + nid = first_node(mask);
> + if (nid == MAX_NUMNODES)
> + return -ENOMEM;
> +
> + ret = add_memory(nid, start, size);
> + return ret ? ret : count;
> +}
> +
> +static const struct file_operations add_node_file_ops = {
> + .write = add_node_store,
> + .llseek = generic_file_llseek,
> +};
> +
> +static int __init node_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_node", S_IWUSR, memhp_debug_root,
> + NULL, &add_node_file_ops))
> + return -ENOMEM;
> +
> + return 0;
> +}
> +
> +module_init(node_debug_init);
> +#endif /* CONFIG_DEBUG_FS */
On Wed, 22 Dec 2010, Andrew Morton wrote:
> > Index: linux-hpe4/mm/memory_hotplug.c
> > ===================================================================
> > --- linux-hpe4.orig/mm/memory_hotplug.c 2010-11-30 12:40:43.757622001 +0800
> > +++ linux-hpe4/mm/memory_hotplug.c 2010-11-30 14:02:33.877622002 +0800
> > @@ -924,3 +924,63 @@
> > }
> > #endif /* CONFIG_MEMORY_HOTREMOVE */
> > EXPORT_SYMBOL_GPL(remove_memory);
> > +
> > +#ifdef CONFIG_DEBUG_FS
> > +#include <linux/debugfs.h>
> > +
> > +static struct dentry *memhp_debug_root;
> > +
> > +static ssize_t add_node_store(struct file *file, const char __user *buf,
> > + size_t count, loff_t *ppos)
> > +{
> > + nodemask_t mask;
>
> NODEMASK_ALLOC()?
>
We traditionally haven't been using NODEMASK_ALLOC() in sysfs (or, in this
case, debugfs) functions because they're never deep in a call chain. Even
for 4K node support, which isn't a supported config on any arch that
allows CONFIG_MEMORY_HOTPLUG, this would only be 512 bytes on the short
stack.
I agree with the remainder of the points in your review and will be
sending fixes against -mm, thanks!
On Wed, 22 Dec 2010 17:38:44 -0800 (PST) David Rientjes <[email protected]> wrote:
> On Wed, 22 Dec 2010, Andrew Morton wrote:
>
> > > Index: linux-hpe4/mm/memory_hotplug.c
> > > ===================================================================
> > > --- linux-hpe4.orig/mm/memory_hotplug.c 2010-11-30 12:40:43.757622001 +0800
> > > +++ linux-hpe4/mm/memory_hotplug.c 2010-11-30 14:02:33.877622002 +0800
> > > @@ -924,3 +924,63 @@
> > > }
> > > #endif /* CONFIG_MEMORY_HOTREMOVE */
> > > EXPORT_SYMBOL_GPL(remove_memory);
> > > +
> > > +#ifdef CONFIG_DEBUG_FS
> > > +#include <linux/debugfs.h>
> > > +
> > > +static struct dentry *memhp_debug_root;
> > > +
> > > +static ssize_t add_node_store(struct file *file, const char __user *buf,
> > > + size_t count, loff_t *ppos)
> > > +{
> > > + nodemask_t mask;
> >
> > NODEMASK_ALLOC()?
> >
>
> We traditionally haven't been using NODEMASK_ALLOC() in sysfs (or, in this
> case, debugfs) functions because they're never deep in a call chain. Even
> for 4K node support, which isn't a supported config on any arch that
> allows CONFIG_MEMORY_HOTPLUG, this would only be 512 bytes on the short
> stack.
I bet linux-2.6.227 supports a meganode.
Add an interface to allow new nodes to be added when performing memory
hot-add. This provides a convenient interface to test memory hotplug
notifier callbacks and surrounding hotplug code when new nodes are
onlined without actually having a machine with such hotpluggable SRAT
entries.
This adds a new debugfs interface at /sys/kernel/debug/hotplug/add_node
that behaves in a similar way to the memory hot-add "probe" interface.
Its format is size@start, where "size" is the size of the new node to be
added and "start" is the physical address of the new memory.
The new node id is a currently offline, but possible, node. The bit must
be set in node_possible_map so that nr_node_ids is sized appropriately.
For emulation on x86, for example, it would be possible to set aside
memory for hotplugged nodes (say, anything above 2G) and to add an
additional four nodes as being possible on boot with
mem=2G numa=possible=4
and then creating a new 128M node at runtime:
# echo 128M@0x80000000 > /sys/kernel/debug/hotplug/add_node
On node 1 totalpages: 0
init_memory_mapping: 0000000080000000-0000000088000000
0080000000 - 0088000000 page 2M
Once the new node has been added, its memory can be onlined. If this
memory represents memory section 16, for example:
# echo online > /sys/devices/system/memory/memory16/state
Built 2 zonelists in Node order, mobility grouping on. Total pages: 514846
Policy zone: Normal
[ The memory section(s) mapped to a particular node are visible via
/sys/devices/system/node/node1, in this example. ]
The new node is now hotplugged and ready for testing.
Signed-off-by: David Rientjes <[email protected]>
---
Documentation/memory-hotplug.txt | 24 +++++++++++++
mm/memory_hotplug.c | 69 ++++++++++++++++++++++++++++++++++++++
2 files changed, 93 insertions(+), 0 deletions(-)
diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt
--- a/Documentation/memory-hotplug.txt
+++ b/Documentation/memory-hotplug.txt
@@ -18,6 +18,7 @@ be changed often.
4. Physical memory hot-add phase
4.1 Hardware(Firmware) Support
4.2 Notify memory hot-add event by hand
+ 4.3 Node hotplug emulation
5. Logical Memory hot-add phase
5.1. State of memory
5.2. How to online memory
@@ -215,6 +216,29 @@ current implementation). You'll have to online memory by yourself.
Please see "How to online memory" in this text.
+4.3 Node hotplug emulation
+------------
+With debugfs, it is possible to test node hotplug by assigning the newly
+added memory to a new node id when using a different interface with a similar
+behavior to "probe" described in section 4.2. If a node id is possible
+(there are bits in /sys/devices/system/memory/possible that are not online),
+then it may be used to emulate a newly added node as the result of memory
+hotplug by using the debugfs "add_node" interface.
+
+The add_node interface is located at "hotplug/add_node" at the debugfs mount
+point.
+
+You can create a new node of a specified size starting at the physical
+address of new memory by
+
+% echo size@start_address_of_new_memory > /sys/kernel/debug/hotplug/add_node
+
+Where "size" can be represented in megabytes or gigabytes (for example,
+"128M" or "1G"). The minumum size is that of a memory section.
+
+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.
+
------------------------------
5. Logical Memory hot-add phase
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -927,3 +927,72 @@ int remove_memory(u64 start, u64 size)
}
#endif /* CONFIG_MEMORY_HOTREMOVE */
EXPORT_SYMBOL_GPL(remove_memory);
+
+#ifdef CONFIG_DEBUG_FS
+#include <linux/debugfs.h>
+
+static struct dentry *hotplug_debug_root;
+
+static ssize_t add_node_store(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ NODEMASK_ALLOC(nodemask_t, mask, GFP_KERNEL);
+ u64 start, size;
+ char buffer[128];
+ char *p;
+ int nid;
+ int ret;
+
+ if (!mask)
+ return -ENOMEM;
+ memset(buffer, 0, sizeof(buffer));
+ if (count > sizeof(buffer) - 1) {
+ ret = -EINVAL;
+ goto out;
+ }
+ if (copy_from_user(buffer, buf, count)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ ret = -EINVAL;
+ size = memparse(buffer, &p);
+ if (size < ((u64)PAGES_PER_SECTION << PAGE_SHIFT))
+ goto out;
+ if (*p != '@')
+ goto out;
+ if (strict_strtoull(p + 1, 0, &start) < 0)
+ goto out;
+
+ ret = -ENOMEM;
+ nodes_andnot(*mask, node_possible_map, node_online_map);
+ nid = first_node(*mask);
+ if (nid == MAX_NUMNODES)
+ goto out;
+
+ ret = add_memory(nid, start, size);
+out:
+ NODEMASK_FREE(mask);
+ return ret ? ret : count;
+}
+
+static const struct file_operations add_node_file_ops = {
+ .write = add_node_store,
+ .llseek = generic_file_llseek,
+};
+
+static int __init hotplug_debug_init(void)
+{
+ hotplug_debug_root = debugfs_create_dir("hotplug", NULL);
+ if (!hotplug_debug_root)
+ return -ENOMEM;
+
+ if (!debugfs_create_file("add_node", S_IWUSR, hotplug_debug_root,
+ NULL, &add_node_file_ops))
+ return -ENOMEM;
+
+ return 0;
+}
+
+module_init(hotplug_debug_init);
+#endif /* CONFIG_DEBUG_FS */
On Wed, 22 Dec 2010, Andrew Morton wrote:
> > Index: linux-hpe4/mm/memory_hotplug.c
> > ===================================================================
> > --- linux-hpe4.orig/mm/memory_hotplug.c 2010-11-30 12:40:43.757622001 +0800
> > +++ linux-hpe4/mm/memory_hotplug.c 2010-11-30 14:02:33.877622002 +0800
> > @@ -924,3 +924,63 @@
> > }
> > #endif /* CONFIG_MEMORY_HOTREMOVE */
> > EXPORT_SYMBOL_GPL(remove_memory);
> > +
> > +#ifdef CONFIG_DEBUG_FS
> > +#include <linux/debugfs.h>
> > +
> > +static struct dentry *memhp_debug_root;
> > +
> > +static ssize_t add_node_store(struct file *file, const char __user *buf,
> > + size_t count, loff_t *ppos)
> > +{
> > + nodemask_t mask;
>
> NODEMASK_ALLOC()?
>
> > + u64 start, size;
> > + char buffer[64];
> > + char *p;
> > + int nid;
> > + int ret;
> > +
> > + memset(buffer, 0, sizeof(buffer));
> > + if (count > sizeof(buffer) - 1)
> > + count = sizeof(buffer) - 1;
>
> This will cause the write to return a smaller number than `count': a
> short write. Some userspace code may then decide to write the
> remainder of the data (whcih is the correct way to use the write()
> syscall).
>
> Could be a bit dangerous, and perhaps simply declaring an error if too
> much data was written would be a better approach.
>
> > + if (copy_from_user(buffer, buf, count))
> > + return -EFAULT;
> > +
> > + size = memparse(buffer, &p);
> > + if (size < (PAGES_PER_SECTION << PAGE_SHIFT))
>
> PAGES_PER_SECTION has type unsigned long, so the rhs of this comparison
> might overflow on 32-bit, should anyone ever try to use this code on
> 32-bit.
>
> otoh the compiler might do it as 64-bit because the lhs is 64-bit. Not
> sure.
>
> > + return -EINVAL;
> > + if (*p != '@')
> > + return -EINVAL;
> > +
> > + start = simple_strtoull(p + 1, NULL, 0);
>
> You disagreed with checkpatch?
>
> > + nodes_andnot(mask, node_possible_map, node_online_map);
> > + nid = first_node(mask);
> > + if (nid == MAX_NUMNODES)
> > + return -ENOMEM;
> > +
> > + ret = add_memory(nid, start, size);
> > + return ret ? ret : count;
> > +}
> > +
> > +static const struct file_operations add_node_file_ops = {
> > + .write = add_node_store,
> > + .llseek = generic_file_llseek,
> > +};
> > +
> > +static int __init node_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_node", S_IWUSR, memhp_debug_root,
> > + NULL, &add_node_file_ops))
> > + return -ENOMEM;
> > +
> > + return 0;
> > +}
> > +
> > +module_init(node_debug_init);
> > +#endif /* CONFIG_DEBUG_FS */
Shaohui, I'll reply to this message with an updated version of this patch
to address Andrew's comments. You can merge it into your series or Andrew
can take it seperately (although it doesn't do much good without "x86: add
numa=possible command line option" unless you have hotpluggable SRAT
entries and CONFIG_ACPI_NUMA).
> -----Original Message-----
> From: David Rientjes [mailto:[email protected]]
> Sent: Tuesday, December 28, 2010 3:35 PM
> To: Zheng, Shaohui; Andrew Morton
> Cc: [email protected]; [email protected]; [email protected]; [email protected]; Andi Kleen;
> [email protected]; Greg Kroah-Hartman; Li, Haicheng
> Subject: Re: [3/7, v9] NUMA Hotplug Emulator: Add node hotplug emulation
>
>
> Shaohui, I'll reply to this message with an updated version of this patch
> to address Andrew's comments. You can merge it into your series or Andrew
> can take it seperately (although it doesn't do much good without "x86: add
> numa=possible command line option" unless you have hotpluggable SRAT
> entries and CONFIG_ACPI_NUMA).
Okay, thanks David. I will merge it into my series when I send next version.
Thanks & Regards,
Shaohui