[Patch] 2/5 in support of hot-add memory x86_64 create arch_find_node

[Patch] 2/5 in support of hot-add memory x86_64 create arch_find_node

[keith mannthey]

[-- Attachment #1: Type: text/plain, Size: 585 bytes --]

  With the advent of the new ACPI hot-plug memory driver and mechanism
is needed to deal with ACPI add memory events that do not contain the
pxm (node) information. I do not believe that the add-event is required
to contain this information so I create a arch_find_node generic layer
used in the generic add_memory function. 

  If add_memory is called with node < 0 arch_find_node is invoked to
fine the correct node to add the memory. This created the generic
construct of arch_find_node. 

   
This was built against 2.6.18-rc2.

Signed-off-by:  Keith Mannthey <kmannth@us.ibm.com>

[-- Attachment #2: patch-2.6.18-rc2-arch_find_node_generic --]
[-- Type: text/x-patch, Size: 1158 bytes --]

diff -urN orig/include/linux/memory_hotplug.h work/include/linux/memory_hotplug.h
--- orig/include/linux/memory_hotplug.h	2006-07-28 13:57:37.000000000 -0400
+++ work/include/linux/memory_hotplug.h	2006-07-26 20:18:35.000000000 -0400
@@ -132,7 +132,11 @@
 }
 #endif /* CONFIG_NUMA */
 #endif /* CONFIG_HAVE_ARCH_NODEDATA_EXTENSION */
-
+#ifdef CONFIG_ARCH_FIND_NODE
+	extern int arch_find_node(unsigned long, unsigned long);
+#else
+	static inline int arch_find_node(unsigned long a,  unsigned long b) {return 0;}
+#endif
 #else /* ! CONFIG_MEMORY_HOTPLUG */
 /*
  * Stub functions for when hotplug is off
diff -urN orig/mm/memory_hotplug.c work/mm/memory_hotplug.c
--- orig/mm/memory_hotplug.c	2006-07-28 13:57:38.000000000 -0400
+++ work/mm/memory_hotplug.c	2006-07-26 20:18:35.000000000 -0400
@@ -233,12 +233,17 @@
 
 
 
-int add_memory(int nid, u64 start, u64 size)
+int add_memory(int node, u64 start, u64 size)
 {
 	pg_data_t *pgdat = NULL;
 	int new_pgdat = 0;
-	int ret;
+	int ret,nid;
 
+	if (node < 0) 
+		nid = arch_find_node(start,size);
+	else
+		nid = node;
+	
 	if (!node_online(nid)) {
 		pgdat = hotadd_new_pgdat(nid, start);
 		if (!pgdat)

Re: [discuss] [Patch] 2/5 in support of hot-add memory x86_64 create arch_find_node

[Andi Kleen]

On Saturday 29 July 2006 04:52, keith mannthey wrote:
>   With the advent of the new ACPI hot-plug memory driver and mechanism
> is needed to deal with ACPI add memory events that do not contain the
> pxm (node) information. I do not believe that the add-event is required
> to contain this information so I create a arch_find_node generic layer
> used in the generic add_memory function.
>
>   If add_memory is called with node < 0 arch_find_node is invoked to
> fine the correct node to add the memory. This created the generic
> construct of arch_find_node.

It would be cleaner to always call add_memory from architecture specific
code instead of such ugly hooks

-Andi

Re: [discuss] [Patch] 2/5 in support of hot-add memory x86_64 create arch_find_node

[keith mannthey]

On Sat, 2006-07-29 at 18:25 +0200, Andi Kleen wrote:
> On Saturday 29 July 2006 04:52, keith mannthey wrote:
> >   With the advent of the new ACPI hot-plug memory driver and mechanism
> > is needed to deal with ACPI add memory events that do not contain the
> > pxm (node) information. I do not believe that the add-event is required
> > to contain this information so I create a arch_find_node generic layer
> > used in the generic add_memory function.
> >
> >   If add_memory is called with node < 0 arch_find_node is invoked to
> > fine the correct node to add the memory. This created the generic
> > construct of arch_find_node.
> 
> It would be cleaner to always call add_memory from architecture specific
> code instead of such ugly hooks

Since 2.6.18 it goes

acpi (generic calling add_memory)
add_memory (generic)
arch_add_memory (x86_64)
__add_pages (generic)

The generic add_memory call is good as it does the dynamic pgdat
allocation for new nodes.  The generic add_memory call need the correct
node infomation.  

Do you think we should do 

acpi (generic calling add_memory)
arch_pre_add_memory? (x86_64)
add_memory (generic)
arch_add_memory (x86_64)
__add_pages (generic)

? 
It would just create a function hook. 

Thanks, 
  Keith 

Re: [discuss] [Patch] 2/5 in support of hot-add memory x86_64 create arch_find_node

[KAMEZAWA Hiroyuki]

On Sat, 29 Jul 2006 18:25:15 +0200
Andi Kleen <ak@suse.de> wrote:

> On Saturday 29 July 2006 04:52, keith mannthey wrote:
> >   With the advent of the new ACPI hot-plug memory driver and mechanism
> > is needed to deal with ACPI add memory events that do not contain the
> > pxm (node) information. I do not believe that the add-event is required
> > to contain this information so I create a arch_find_node generic layer
> > used in the generic add_memory function.
> >
> >   If add_memory is called with node < 0 arch_find_node is invoked to
> > fine the correct node to add the memory. This created the generic
> > construct of arch_find_node.
> 
> It would be cleaner to always call add_memory from architecture specific
> code instead of such ugly hooks
> 
Hi,  Keith 

I don't like insert such a check (nid < 0) in add_memory(), either.
Could you add it before calling add_memory() ?
(for example, find_pxm parh in acpi's add memory code.)

-Kame

Re: [Lhms-devel] [discuss] [Patch] 2/5 in support of hot-add memory x86_64 create arch_find_node

[Yasunori Goto]

> On Sat, 29 Jul 2006 18:25:15 +0200
> Andi Kleen <ak@suse.de> wrote:
> 
> > On Saturday 29 July 2006 04:52, keith mannthey wrote:
> > >   With the advent of the new ACPI hot-plug memory driver and mechanism
> > > is needed to deal with ACPI add memory events that do not contain the
> > > pxm (node) information. I do not believe that the add-event is required
> > > to contain this information so I create a arch_find_node generic layer
> > > used in the generic add_memory function.
> > >
> > >   If add_memory is called with node < 0 arch_find_node is invoked to
> > > fine the correct node to add the memory. This created the generic
> > > construct of arch_find_node.
> > 
> > It would be cleaner to always call add_memory from architecture specific
> > code instead of such ugly hooks
> > 
> Hi,  Keith 
> 
> I don't like insert such a check (nid < 0) in add_memory(), either.
> Could you add it before calling add_memory() ?
> (for example, find_pxm parh in acpi's add memory code.)

Agree.
I think that arch_find_node() should be called in acpi_get_node().

For the time being, I would like to post folloing patch for 2.6.18
to fix returning -1 if _PXM is not defined.
Because, not only your case, but also there might be a case that
hot add code will be executed with NUMA kernel on NON-NUMA box.

Then, arch_find_node() should be add before this line.

Thanks.

-----

 drivers/acpi/numa.c |    4 ++++
 1 files changed, 4 insertions(+)

Index: pxm_find1/drivers/acpi/numa.c
===================================================================
--- pxm_find1.orig/drivers/acpi/numa.c	2006-07-31 14:59:48.000000000 +0900
+++ pxm_find1/drivers/acpi/numa.c	2006-07-31 15:11:06.000000000 +0900
@@ -263,6 +263,10 @@ int acpi_get_node(acpi_handle *handle)
 	if (pxm >= 0)
 		node = acpi_map_pxm_to_node(pxm);
 
+	/* _PXM might not be defined by firmware. */
+	if (node < 0)
+		node = 0;
+
 	return node;
 }
 EXPORT_SYMBOL(acpi_get_node);


-- 
Yasunori Goto