memory hotplug for ia64 (linux-2.6.7) [0/2]

Hello,
I updated the memory hotplug patch for an IPF NUMA machines which posted in April.
The patch is against linux 2.6.7 and works with memory hotplug patch which Takahashi-san posted on July 14.

Known issues(under investigation):

- remap function may be unable to mmigrate all pages.
- unplug-node function may fail, if page size is other than 4K byte.
- kswapd doesn't terminate when a node is unplugged.

How to apply:

1) First of all, apply patches which Takahashi-san posted on July 14

    without [15-16/16].
    *If patches of [15-16/16] are applied, compile error will occur
     on ia64.

2) Apply this set of patches.

Thank you,
Fumihiro Terasawa.

Hi,

The following patch complements ones that Terasawa-san posted.
(http://marc.theaimsgroup.com/?l=linux-kernel&m=109031522707608&w=2)
This enables IPF machine to plug nodes.

If you want to know the details about how to plug, please refer to Iwamoto-san's web page.
http://people.valinux.co.jp/~iwamoto/mh.html

Known issues / TODO items:
- This patch can only plug a unpluged node again. In other words, it cannot plug a new node.
- Plug and unplug are unrepeatable.
- After plugging a node, a memory usage statistics per zone displayed by "/proc/memhotplug" becomes invalid.

How to apply:
1) First of all, apply patches which Takahashi-san posted on July 14 without [15-16/16].
*If patches of [15-16/16] are applied, compile error will occur on ia64.
2) Apply patches which Terasawa-san posted on July 20.
3) Apply patches which Yoshida-san posted on July 20.
4) And, apply my patch.

Thanks,
Fumitake ABE

diff -dupr linux-2.6.7/arch/ia64/mm/discontig.c linux-2.6.7-mhp/arch/ia64/mm/discontig.c
@@ -38,7 +38,11 @@ struct early_node_data {
 	unsigned long max_pfn;
 };
 
+#ifndef CONFIG_MEMHOTPLUG
 static struct early_node_data mem_data[NR_NODES] __initdata;
+#else
+static struct early_node_data mem_data[NR_NODES];
+#endif
 
 /**
  * reassign_cpu_only_nodes - called from find_memory to move CPU-only 

nodes to a memory node
@@ -179,8 +183,12 @@ static void __init reassign_cpu_only_nod
* memmap. We also update min_low_pfn and max_low_pfn here as we receive
* memory ranges from the caller.
*/
+#ifdef CONFIG_MEMHOTPLUG
+static int build_node_maps(unsigned long start, unsigned long len, int node) +#else
static int __init build_node_maps(unsigned long start, unsigned long len,
int node)
+#endif
{
unsigned long cstart, epfn, end = start + len;
struct bootmem_data *bdp = &mem_data[node].bootmem_data;
@@ -249,8 +257,13 @@ static int early_nr_cpus_node(int node)
* outside of this function and use alloc_bootmem_node(), but doing it
here
* is straightforward and we get the alignments we want so...
*/
+#ifdef CONFIG_MEMHOTPLUG
+static int find_pernode_space(unsigned long start, unsigned long len,
+ int node)
+#else
static int __init find_pernode_space(unsigned long start, unsigned
long len,
int node)
+#endif
{
unsigned long epfn, cpu, cpus;
unsigned long pernodesize = 0, pernode, pages, mapsize;
@@ -332,14 +345,40 @@ static int __init find_pernode_space(uns
* for all the entries in the EFI memory map, the bootmem allocator will
* be ready to service allocation requests.
*/
+#ifdef CONFIG_MEMHOTPLUG
+static int free_node_bootmem(unsigned long start, unsigned long len,
+ int node)
+#else
static int __init free_node_bootmem(unsigned long start, unsigned long
len,
int node)
+#endif
{
free_bootmem_node(mem_data[node].pgdat, start, len);

return 0;
}

+static void reserve_pernode_space_core(int node)
+{
+ unsigned long base, size, pages;
+ struct bootmem_data *bdp;
+ pg_data_t *pdp;
+
+ pdp = mem_data[node].pgdat;
+ bdp = pdp->bdata;
+
+ /* First the bootmem_map itself */
+ pages = bdp->node_low_pfn - (bdp->node_boot_start>>PAGE_SHIFT);
+ size = bootmem_bootmap_pages(pages) << PAGE_SHIFT;
+ base = __pa(bdp->node_bootmem_map);
+ reserve_bootmem_node(pdp, base, size);
+
+ /* Now the per-node space */
+ size = mem_data[node].pernode_size;
+ base = __pa(mem_data[node].pernode_addr);
+ reserve_bootmem_node(pdp, base, size);
+}
+
/**
* reserve_pernode_space - reserve memory for per-node space *
@@ -349,26 +388,10 @@ static int __init free_node_bootmem(unsi
*/
static void __init reserve_pernode_space(void)
{
- unsigned long base, size, pages;
- struct bootmem_data *bdp;
int node;

- for (node = 0; node < numnodes; node++) {
- pg_data_t *pdp = mem_data[node].pgdat;
-
- bdp = pdp->bdata;
-
- /* First the bootmem_map itself */
- pages = bdp->node_low_pfn - (bdp->node_boot_start>>PAGE_SHIFT);
- size = bootmem_bootmap_pages(pages) << PAGE_SHIFT;
- base = __pa(bdp->node_bootmem_map);
- reserve_bootmem_node(pdp, base, size);
-
- /* Now the per-node space */
- size = mem_data[node].pernode_size;
- base = __pa(mem_data[node].pernode_addr);
- reserve_bootmem_node(pdp, base, size);
- }
+ for (node = 0; node < numnodes; node++)
+ reserve_pernode_space_core(node);
}

/**
@@ -674,10 +697,150 @@ void paging_init(void)
zero_page_memmap_ptr = virt_to_page(ia64_imva(empty_zero_page));
}

-/* Not support HotAdd memory */
+/* for hotplug */
+
+void
+paging_init_for_new_node(unsigned long start, unsigned long len, int nid) +{
+ unsigned long max_dma;
+ unsigned long zones_size[MAX_NR_ZONES];
+ unsigned long zholes_size[MAX_NR_ZONES];
+ unsigned long max_gap;
+ unsigned long vstart, vend;
+
+ max_dma = virt_to_phys((void *) MAX_DMA_ADDRESS) >> PAGE_SHIFT;
+ max_gap = 0;
+
+ mem_data[nid].min_pfn = ~0UL;
+
+ count_node_pages(start, len, nid);
+
+ memset(zones_size, 0, sizeof(zones_size));
+ memset(zholes_size, 0, sizeof(zholes_size));
+
+ num_physpages += mem_data[nid].num_physpages;
+
+ zones_size[ZONE_NORMAL] = mem_data[nid].max_pfn -
+ mem_data[nid].min_pfn;
+ zholes_size[ZONE_NORMAL] = mem_data[nid].max_pfn -
+ mem_data[nid].min_pfn -
+ mem_data[nid].num_physpages; /* <- Is this valid? */
+
+ vstart = PAGE_ALIGN(PAGE_OFFSET + start);
+ vend = (vstart + len) & PAGE_MASK;
+ create_mem_map_page_table(vstart, vend, 0);
+
+ free_area_init_node(nid, NODE_DATA(nid),
+ vmem_map + mem_data[nid].min_pfn,
+ zones_size, mem_data[nid].min_pfn, zholes_size);
+}
+
+/* Temporary */
+void
+get_new_node_memory_info(int nid, unsigned long *start, unsigned long *end) +{
+ *start = mem_data[nid].min_pfn << PAGE_SHIFT;
+ *end = mem_data[nid].max_pfn << PAGE_SHIFT;
+ printk("%s: start = %016lx, end = %016lx\n",
+ __FUNCTION__, *start, *end);
+}
+
void
plug_node(int nid)
-{}
+{
+ int i, j;
+ int cpu;
+ unsigned long start, end;
+ unsigned long prev_min_low_pfn, prev_max_low_pfn;
+ unsigned long pernode, pernodesize, map;
+ struct bootmem_data *bdp;
+ pg_data_t **pgdat;
+
+ /* TBD: Validness of nid is needed to check here. */
+
+ prev_min_low_pfn = min_low_pfn;
+ prev_max_low_pfn = max_low_pfn;
+
+ /* 1: check memory range */
+ get_new_node_memory_info(nid, &start, &end);
+
+ memset(&mem_data[nid], 0, sizeof(struct early_node_data));
+
+ build_node_maps(start, end - start, nid);
+ find_pernode_space(start, end - start, nid);
+
+ bdp = &mem_data[nid].bootmem_data;
+ pernode = mem_data[nid].pernode_addr;
+ pernodesize = mem_data[nid].pernode_size;
+ map = pernode + pernodesize;
+
+ if (!pernode) {
+ printk("space for the new node %d could not be allocated!",
+ nid);
+ min_low_pfn = prev_min_low_pfn;
+ max_low_pfn = prev_max_low_pfn;
+ return;
+ }
+
+ init_bootmem_node(mem_data[nid].pgdat,
+ map>>PAGE_SHIFT,
+ bdp->node_boot_start>>PAGE_SHIFT,
+ bdp->node_low_pfn);
+
+ free_node_bootmem(start, end - start, nid);
+
+ reserve_pernode_space_core(nid);
+
+ /* initialize_pernode_data() for pluged node */
+ for(cpu = 0; cpu < NR_CPUS; cpu++) {
+ per_cpu(cpu_info, cpu).node_data->pg_data_ptrs[nid]
+ = mem_data[nid].pgdat;
+ }
+
+ max_pfn = max_low_pfn;
+
+ paging_init_for_new_node(start, end - start, nid);
+
+ NODE_DATA(nid)->removable = 1;
+
+ for(pgdat = &pgdat_list; *pgdat; pgdat = &(*pgdat)->pgdat_next)
+ if ((*pgdat)->node_id > nid) {
+ NODE_DATA(nid)->pgdat_next = *pgdat;
+ *pgdat = NODE_DATA(nid);
+ break;
+ }
+
+ if (*pgdat == NULL)
+ *pgdat = NODE_DATA(nid);
+ {
+ struct zone *z;
+ int lim=0;
+ printk("%s: zone = ", __FUNCTION__);
+ for_each_zone (z) {
+ printk("%p ", z);
+ if(lim++ > 10)
+ break;
+ }
+ printk("\n");
+ }
+
+ for (i = 0; i < MAX_NR_ZONES; i++) {
+ struct zone *z;
+ struct page *p;
+
+ z = &NODE_DATA(nid)->node_zones[i];
+
+ for (j = 0; j < z->spanned_pages; j++) {
+ p = &z->zone_mem_map[j];
+ ClearPageReserved(p);
+ set_page_count(p, 1);
+ __free_page(p);
+ }
+ }
+ kswapd_start_one(NODE_DATA(nid));
+ setup_per_zone_pages_min();
+}
+

void
enable_node(int node)

diff -dupr linux-2.6.7/arch/ia64/mm/init.c linux-2.6.7-mhp/arch/ia64/mm/init.c
@@ -446,6 +446,15 @@ memmap_init (struct page *start, unsigne
 		args.nid = nid;
 		args.zone = zone;
 
+#ifdef CONFIG_MEMHOTPLUG
+		if(system_state == SYSTEM_RUNNING) {
+			unsigned long pstart, pend;
+			get_new_node_memory_info(nid, &pstart, &pend);
+			pstart = PAGE_ALIGN(pstart + PAGE_OFFSET);
+			pend = (pend + PAGE_OFFSET) & PAGE_MASK;
+			virtual_memmap_init(pstart, pend, &args);
+		} else
+#endif
 		efi_memmap_walk(virtual_memmap_init, &args);
 	}
 }

diff -dupr linux-2.6.7/include/linux/bootmem.h linux-2.6.7-mhp/include/linux/bootmem.h
@@ -36,7 +36,11 @@ typedef struct bootmem_data {
 					 * up searching */
 } bootmem_data_t;
 
+#ifndef CONFIG_MEMHOTPLUG
 extern unsigned long __init bootmem_bootmap_pages (unsigned long);
+#else /* CONFIG_MEMHOTPLUG */
+extern unsigned long bootmem_bootmap_pages (unsigned long);
+#endif
 extern unsigned long __init init_bootmem (unsigned long addr, unsigned 

long memend);
extern void __init free_bootmem (unsigned long addr, unsigned long size); extern void * __init __alloc_bootmem (unsigned long size, unsigned
long align, unsigned long goal);
@@ -53,11 +57,18 @@ extern void __init reserve_bootmem (unsi
#endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */
extern unsigned long __init free_all_bootmem (void);

+#ifndef CONFIG_MEMHOTPLUG
extern unsigned long __init init_bootmem_node (pg_data_t *pgdat,
unsigned long freepfn, unsigned long startpfn, unsigned long endpfn);
extern void __init reserve_bootmem_node (pg_data_t *pgdat, unsigned
long physaddr, unsigned long size);
extern void __init free_bootmem_node (pg_data_t *pgdat, unsigned long
addr, unsigned long size);
-extern unsigned long __init free_all_bootmem_node (pg_data_t *pgdat);
extern void * __init __alloc_bootmem_node (pg_data_t *pgdat, unsigned
long size, unsigned long align, unsigned long goal);
+#else /* CONFIG_MEMHOTPLUG */
+extern unsigned long init_bootmem_node (pg_data_t *pgdat, unsigned long freepfn, unsigned long startpfn, unsigned long endpfn); +extern void reserve_bootmem_node (pg_data_t *pgdat, unsigned long physaddr, unsigned long size);
+extern void free_bootmem_node (pg_data_t *pgdat, unsigned long addr, unsigned long size);
+extern void * __alloc_bootmem_node (pg_data_t *pgdat, unsigned long size, unsigned long align, unsigned long goal); +#endif
+extern unsigned long __init free_all_bootmem_node (pg_data_t *pgdat);
#ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
#define alloc_bootmem_node(pgdat, x) \
__alloc_bootmem_node((pgdat), (x), SMP_CACHE_BYTES,
__pa(MAX_DMA_ADDRESS))

diff -dupr linux-2.6.7/mm/bootmem.c linux-2.6.7-mhp/mm/bootmem.c
@@ -28,7 +28,11 @@ unsigned long min_low_pfn;
 unsigned long max_pfn;
 
 /* return the number of _pages_ that will be allocated for the boot 

bitmap */
+#ifdef CONFIG_MEMHOTPLUG
+unsigned long bootmem_bootmap_pages (unsigned long pages) +#else
unsigned long __init bootmem_bootmap_pages (unsigned long pages)
+#endif
{
unsigned long mapsize;

@@ -42,14 +46,26 @@ unsigned long __init bootmem_bootmap_pag
/*
* Called once to set up the allocator itself.
*/
+#ifdef CONFIG_MEMHOTPLUG
+static unsigned long init_bootmem_core (pg_data_t *pgdat,
+ unsigned long mapstart, unsigned long start, unsigned long end)
+#else
static unsigned long __init init_bootmem_core (pg_data_t *pgdat,
unsigned long mapstart, unsigned long start, unsigned long end)
+#endif
{
bootmem_data_t *bdata = pgdat->bdata;
unsigned long mapsize = ((end - start)+7)/8;

- pgdat->pgdat_next = pgdat_list;
- pgdat_list = pgdat;
+#ifdef CONFIG_MEMHOTPLUG
+ if (system_state != SYSTEM_RUNNING) {
+#endif
+ pgdat->pgdat_next = pgdat_list;
+ pgdat_list = pgdat;
+#ifdef CONFIG_MEMHOTPLUG
+ } else
+ pgdat->pgdat_next = NULL;
+#endif

mapsize = (mapsize + (sizeof(long) - 1UL)) & ~(sizeof(long) - 1UL); bdata->node_bootmem_map = phys_to_virt(mapstart << PAGE_SHIFT);
@@ -70,7 +86,11 @@ static unsigned long __init init_bootmem
* might be used for boot-time allocations - or it might get added
* to the free page pool later on.
*/
+#ifdef CONFIG_MEMHOTPLUG
+static void reserve_bootmem_core(bootmem_data_t *bdata, unsigned long addr, unsigned long size) +#else
static void __init reserve_bootmem_core(bootmem_data_t *bdata,
unsigned long addr, unsigned long size)
+#endif
{
unsigned long i;
/*
@@ -95,7 +115,11 @@ static void __init reserve_bootmem_core(
}
}

+#ifdef CONFIG_MEMHOTPLUG
+static void free_bootmem_core(bootmem_data_t *bdata, unsigned long addr, unsigned long size) +#else
static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned
long addr, unsigned long size)
+#endif
{
unsigned long i;
unsigned long start;
@@ -138,7 +162,11 @@ static void __init free_bootmem_core(boo
*
* NOTE: This function is _not_ reentrant.
*/
+#ifdef CONFIG_MEMHOTPLUG
+static void *
+#else
static void * __init
+#endif
__alloc_bootmem_core(struct bootmem_data *bdata, unsigned long size,
unsigned long align, unsigned long goal)
{
@@ -299,17 +327,29 @@ static unsigned long __init free_all_boo
return total;
}

+#ifdef CONFIG_MEMHOTPLUG
+unsigned long init_bootmem_node (pg_data_t *pgdat, unsigned long freepfn, unsigned long startpfn, unsigned long endpfn) +#else
unsigned long __init init_bootmem_node (pg_data_t *pgdat, unsigned
long freepfn, unsigned long startpfn, unsigned long endpfn)
+#endif
{
return(init_bootmem_core(pgdat, freepfn, startpfn, endpfn));
}

+#ifdef CONFIG_MEMHOTPLUG
+void reserve_bootmem_node (pg_data_t *pgdat, unsigned long physaddr, unsigned long size) +#else
void __init reserve_bootmem_node (pg_data_t *pgdat, unsigned long
physaddr, unsigned long size)
+#endif
{
reserve_bootmem_core(pgdat->bdata, physaddr, size);
}

+#ifdef CONFIG_MEMHOTPLUG
+void free_bootmem_node (pg_data_t *pgdat, unsigned long physaddr, unsigned long size) +#else
void __init free_bootmem_node (pg_data_t *pgdat, unsigned long
physaddr, unsigned long size)
+#endif
{
free_bootmem_core(pgdat->bdata, physaddr, size);
}
@@ -363,7 +403,11 @@ void * __init __alloc_bootmem (unsigned
return NULL;
}

+#ifdef CONFIG_MEMHOTPLUG
+void * __alloc_bootmem_node (pg_data_t *pgdat, unsigned long size, unsigned long align, unsigned long goal) +#else
void * __init __alloc_bootmem_node (pg_data_t *pgdat, unsigned long
size, unsigned long align, unsigned long goal)
+#endif
{
void *ptr;

diff -dupr linux-2.6.7/mm/page_alloc.c linux-2.6.7-mhp/mm/page_alloc.c
@@ -991,7 +991,11 @@ EXPORT_SYMBOL(__alloc_pages);
 /* Early boot: Everything is done by one cpu, but the data structures 

will be
* used by all cpus - spread them on all nodes.
*/
+#ifdef CONFIG_MEMHOTPLUG
+static unsigned long get_boot_pages(unsigned int gfp_mask, unsigned int order) +#else
static __init unsigned long get_boot_pages(unsigned int gfp_mask,
unsigned int order)
+#endif
{
static int nodenr;
int i = nodenr;

Hi,

The patch which I sent on July 21 was invalid because a linefeed was inserted in the 72nd character. So, I resend my correct patch.

Thanks,
Fumitake Abe

-------- Original Message --------
Subject: Re: [PATCH] memory hotplug for ia64 (linux-2.6.7) [0/2]
Date: Wed, 21 Jul 2004 17:35:41 -0700
From: Fumitake ABE <[email protected]>
To: lhms-devel <[email protected]>, linux-kernel <[email protected]>
References: <[email protected]>

Hi,

The following patch complements ones that Terasawa-san posted.
(http://marc.theaimsgroup.com/?l=linux-kernel&m=109031522707608&w=2)
This enables IPF machine to plug nodes.

If you want to know the details about how to plug, please refer to Iwamoto-san's web page.
http://people.valinux.co.jp/~iwamoto/mh.html

Known issues / TODO items:
- This patch can only plug a unpluged node again. In other words, it cannot plug a new node.
- Plug and unplug are unrepeatable.
- After plugging a node, a memory usage statistics per zone displayed by "/proc/memhotplug" becomes invalid.

How to apply:
1) First of all, apply patches which Takahashi-san posted on July 14 without [15-16/16].
*If patches of [15-16/16] are applied, compile error will occur on ia64.
2) Apply patches which Terasawa-san posted on July 20.
3) Apply patches which Yoshida-san posted on July 20.
4) And, apply my patch.

Thanks,
Fumitake ABE

diff -dupr linux-2.6.7/arch/ia64/mm/discontig.c linux-2.6.7-mhp/arch/ia64/mm/discontig.c
@@ -38,7 +38,11 @@ struct early_node_data {
     unsigned long max_pfn;
 };
 
+#ifndef CONFIG_MEMHOTPLUG
 static struct early_node_data mem_data[NR_NODES] __initdata;
+#else
+static struct early_node_data mem_data[NR_NODES];
+#endif
 
 /**
  * reassign_cpu_only_nodes - called from find_memory to move CPU-only nodes to a memory node

@@ -179,8 +183,12 @@ static void __init reassign_cpu_only_nod
  * memmap.  We also update min_low_pfn and max_low_pfn here as we receive
  * memory ranges from the caller.
  */
+#ifdef CONFIG_MEMHOTPLUG
+static int build_node_maps(unsigned long start, unsigned long len, int node)
+#else
 static int __init build_node_maps(unsigned long start, unsigned long len,
                   int node)
+#endif
 {
     unsigned long cstart, epfn, end = start + len;
     struct bootmem_data *bdp = &mem_data[node].bootmem_data;

@@ -249,8 +257,13 @@ static int early_nr_cpus_node(int node)
  * outside of this function and use alloc_bootmem_node(), but doing it here
  * is straightforward and we get the alignments we want so...
  */
+#ifdef CONFIG_MEMHOTPLUG
+static int find_pernode_space(unsigned long start, unsigned long len,
+                  int node)
+#else
 static int __init find_pernode_space(unsigned long start, unsigned long len,
                      int node)
+#endif
 {
     unsigned long epfn, cpu, cpus;
     unsigned long pernodesize = 0, pernode, pages, mapsize;

@@ -332,14 +345,40 @@ static int __init find_pernode_space(uns
  * for all the entries in the EFI memory map, the bootmem allocator will
  * be ready to service allocation requests.
  */
+#ifdef CONFIG_MEMHOTPLUG
+static int free_node_bootmem(unsigned long start, unsigned long len,
+                 int node)
+#else
 static int __init free_node_bootmem(unsigned long start, unsigned long len,
                     int node)
+#endif
 {
     free_bootmem_node(mem_data[node].pgdat, start, len);
 
     return 0;
 }
 
+static void reserve_pernode_space_core(int node)
+{
+    unsigned long base, size, pages;
+    struct bootmem_data *bdp;
+    pg_data_t *pdp;
+
+    pdp = mem_data[node].pgdat;
+    bdp = pdp->bdata;
+
+    /* First the bootmem_map itself */
+    pages = bdp->node_low_pfn - (bdp->node_boot_start>>PAGE_SHIFT);
+    size = bootmem_bootmap_pages(pages) << PAGE_SHIFT;
+    base = __pa(bdp->node_bootmem_map);
+    reserve_bootmem_node(pdp, base, size);
+
+    /* Now the per-node space */
+    size = mem_data[node].pernode_size;
+    base = __pa(mem_data[node].pernode_addr);
+    reserve_bootmem_node(pdp, base, size);
+}
+
 /**
  * reserve_pernode_space - reserve memory for per-node space
  *

@@ -349,26 +388,10 @@ static int __init free_node_bootmem(unsi
  */
 static void __init reserve_pernode_space(void)
 {
-    unsigned long base, size, pages;
-    struct bootmem_data *bdp;
     int node;
 
-    for (node = 0; node < numnodes; node++) {
-        pg_data_t *pdp = mem_data[node].pgdat;
-
-        bdp = pdp->bdata;
-
-        /* First the bootmem_map itself */
-        pages = bdp->node_low_pfn - (bdp->node_boot_start>>PAGE_SHIFT);
-        size = bootmem_bootmap_pages(pages) << PAGE_SHIFT;
-        base = __pa(bdp->node_bootmem_map);
-        reserve_bootmem_node(pdp, base, size);
-
-        /* Now the per-node space */
-        size = mem_data[node].pernode_size;
-        base = __pa(mem_data[node].pernode_addr);
-        reserve_bootmem_node(pdp, base, size);
-    }
+    for (node = 0; node < numnodes; node++)
+        reserve_pernode_space_core(node);
 }
 
 /**

@@ -674,10 +697,150 @@ void paging_init(void)
     zero_page_memmap_ptr = virt_to_page(ia64_imva(empty_zero_page));
 }
 
-/* Not support HotAdd memory */
+/* for hotplug */
+
+void
+paging_init_for_new_node(unsigned long start, unsigned long len, int nid)
+{
+    unsigned long max_dma;
+    unsigned long zones_size[MAX_NR_ZONES];
+    unsigned long zholes_size[MAX_NR_ZONES];
+    unsigned long max_gap;
+    unsigned long vstart, vend;
+
+    max_dma = virt_to_phys((void *) MAX_DMA_ADDRESS) >> PAGE_SHIFT;
+    max_gap = 0;
+
+    mem_data[nid].min_pfn = ~0UL;
+
+    count_node_pages(start, len, nid);
+
+    memset(zones_size, 0, sizeof(zones_size));
+    memset(zholes_size, 0, sizeof(zholes_size));
+
+    num_physpages += mem_data[nid].num_physpages;
+
+    zones_size[ZONE_NORMAL] = mem_data[nid].max_pfn -
+        mem_data[nid].min_pfn;
+    zholes_size[ZONE_NORMAL] = mem_data[nid].max_pfn -
+        mem_data[nid].min_pfn -
+        mem_data[nid].num_physpages;  /* <- Is this valid? */
+
+    vstart = PAGE_ALIGN(PAGE_OFFSET + start);
+    vend = (vstart + len) & PAGE_MASK;
+    create_mem_map_page_table(vstart, vend, 0);
+
+    free_area_init_node(nid, NODE_DATA(nid),
+                vmem_map + mem_data[nid].min_pfn,
+                zones_size, mem_data[nid].min_pfn, zholes_size);
+}
+
+/* Temporary */
+void
+get_new_node_memory_info(int nid, unsigned long *start, unsigned long *end)
+{
+    *start = mem_data[nid].min_pfn << PAGE_SHIFT;
+    *end = mem_data[nid].max_pfn << PAGE_SHIFT;
+    printk("%s: start = %016lx, end = %016lx\n",
+        __FUNCTION__, *start, *end);
+}
+
 void
 plug_node(int nid)
-{}
+{
+    int i, j;
+    int cpu;
+    unsigned long start, end;
+    unsigned long prev_min_low_pfn, prev_max_low_pfn;
+    unsigned long pernode, pernodesize, map;
+    struct bootmem_data *bdp;
+    pg_data_t **pgdat;
+
+    /* TBD: Validness of nid is needed to check here. */
+
+    prev_min_low_pfn = min_low_pfn;
+    prev_max_low_pfn = max_low_pfn;
+
+    /* 1: check memory range */
+    get_new_node_memory_info(nid, &start, &end);
+
+    memset(&mem_data[nid], 0, sizeof(struct early_node_data));
+
+    build_node_maps(start, end - start, nid);
+    find_pernode_space(start, end - start, nid);
+
+    bdp = &mem_data[nid].bootmem_data;
+    pernode = mem_data[nid].pernode_addr;
+    pernodesize = mem_data[nid].pernode_size;
+    map = pernode + pernodesize;
+
+    if (!pernode) {
+        printk("space for the new node %d could not be allocated!",
+            nid);
+        min_low_pfn = prev_min_low_pfn;
+        max_low_pfn = prev_max_low_pfn;
+        return;
+    }
+
+    init_bootmem_node(mem_data[nid].pgdat,
+            map>>PAGE_SHIFT,
+            bdp->node_boot_start>>PAGE_SHIFT,
+            bdp->node_low_pfn);
+
+            free_node_bootmem(start, end - start, nid);
+
+    reserve_pernode_space_core(nid);
+
+    /* initialize_pernode_data() for pluged node */
+    for(cpu = 0; cpu < NR_CPUS; cpu++) {
+        per_cpu(cpu_info, cpu).node_data->pg_data_ptrs[nid]
+            = mem_data[nid].pgdat;
+    }
+
+    max_pfn = max_low_pfn;
+
+    paging_init_for_new_node(start, end - start, nid);
+
+    NODE_DATA(nid)->removable = 1;
+
+    for(pgdat = &pgdat_list; *pgdat; pgdat = &(*pgdat)->pgdat_next)
+        if ((*pgdat)->node_id > nid) {
+            NODE_DATA(nid)->pgdat_next = *pgdat;
+            *pgdat = NODE_DATA(nid);
+            break;
+        }
+
+    if (*pgdat == NULL)
+        *pgdat = NODE_DATA(nid);
+    {
+        struct zone *z;
+        int lim=0;
+        printk("%s: zone = ", __FUNCTION__);
+        for_each_zone (z) {
+            printk("%p ", z);
+            if(lim++ > 10)
+                break;
+        }
+        printk("\n");
+    }
+
+    for (i = 0; i < MAX_NR_ZONES; i++) {
+        struct zone *z;
+        struct page *p;
+
+        z = &NODE_DATA(nid)->node_zones[i];
+
+        for (j = 0; j < z->spanned_pages; j++) {
+            p = &z->zone_mem_map[j];
+            ClearPageReserved(p);
+            set_page_count(p, 1);
+            __free_page(p);
+        }
+    }
+    kswapd_start_one(NODE_DATA(nid));
+    setup_per_zone_pages_min();
+}
+
 
 void
 enable_node(int node)

diff -dupr linux-2.6.7/arch/ia64/mm/init.c linux-2.6.7-mhp/arch/ia64/mm/init.c
@@ -446,6 +446,15 @@ memmap_init (struct page *start, unsigne
         args.nid = nid;
         args.zone = zone;
 
+#ifdef CONFIG_MEMHOTPLUG
+        if(system_state == SYSTEM_RUNNING) {
+            unsigned long pstart, pend;
+            get_new_node_memory_info(nid, &pstart, &pend);
+            pstart = PAGE_ALIGN(pstart + PAGE_OFFSET);
+            pend = (pend + PAGE_OFFSET) & PAGE_MASK;
+            virtual_memmap_init(pstart, pend, &args);
+        } else
+#endif
         efi_memmap_walk(virtual_memmap_init, &args);
     }
 }

diff -dupr linux-2.6.7/include/linux/bootmem.h linux-2.6.7-mhp/include/linux/bootmem.h
@@ -36,7 +36,11 @@ typedef struct bootmem_data {
                      * up searching */
 } bootmem_data_t;
 
+#ifndef CONFIG_MEMHOTPLUG
 extern unsigned long __init bootmem_bootmap_pages (unsigned long);
+#else /* CONFIG_MEMHOTPLUG */
+extern unsigned long bootmem_bootmap_pages (unsigned long);
+#endif
 extern unsigned long __init init_bootmem (unsigned long addr, unsigned long memend);
 extern void __init free_bootmem (unsigned long addr, unsigned long size);
 extern void * __init __alloc_bootmem (unsigned long size, unsigned long align, unsigned long goal);

@@ -53,11 +57,18 @@ extern void __init reserve_bootmem (unsi
 #endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */
 extern unsigned long __init free_all_bootmem (void);
 
+#ifndef CONFIG_MEMHOTPLUG
 extern unsigned long __init init_bootmem_node (pg_data_t *pgdat, unsigned long freepfn, unsigned long startpfn, unsigned long endpfn);
 extern void __init reserve_bootmem_node (pg_data_t *pgdat, unsigned long physaddr, unsigned long size);
 extern void __init free_bootmem_node (pg_data_t *pgdat, unsigned long addr, unsigned long size);
-extern unsigned long __init free_all_bootmem_node (pg_data_t *pgdat);
 extern void * __init __alloc_bootmem_node (pg_data_t *pgdat, unsigned long size, unsigned long align, unsigned long goal);
+#else /* CONFIG_MEMHOTPLUG */
+extern unsigned long init_bootmem_node (pg_data_t *pgdat, unsigned long freepfn, unsigned long startpfn, unsigned long endpfn);
+extern void reserve_bootmem_node (pg_data_t *pgdat, unsigned long physaddr, unsigned long size);
+extern void free_bootmem_node (pg_data_t *pgdat, unsigned long addr, unsigned long size);
+extern void * __alloc_bootmem_node (pg_data_t *pgdat, unsigned long size, unsigned long align, unsigned long goal);
+#endif
+extern unsigned long __init free_all_bootmem_node (pg_data_t *pgdat);
 #ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE
 #define alloc_bootmem_node(pgdat, x) \
     __alloc_bootmem_node((pgdat), (x), SMP_CACHE_BYTES, __pa(MAX_DMA_ADDRESS))

diff -dupr linux-2.6.7/mm/page_alloc.c linux-2.6.7-mhp/mm/page_alloc.c
@@ -991,7 +991,11 @@ EXPORT_SYMBOL(__alloc_pages);
 /* Early boot: Everything is done by one cpu, but the data structures will be
  * used by all cpus - spread them on all nodes.
  */
+#ifdef CONFIG_MEMHOTPLUG
+static unsigned long get_boot_pages(unsigned int gfp_mask, unsigned int order)
+#else
 static __init unsigned long get_boot_pages(unsigned int gfp_mask, unsigned int order)
+#endif
 {
 static int nodenr;
     int i = nodenr;