c/s 20599 caused the hash shift to become significantly smaller on
systems with an SRAT like this
(XEN) SRAT: Node 0 PXM 0 0-a0000
(XEN) SRAT: Node 0 PXM 0 100000-80000000
(XEN) SRAT: Node 1 PXM 1 80000000-d0000000
(XEN) SRAT: Node 1 PXM 1 100000000-130000000
Comined with the static size of the memnodemap[] array, NUMA got
therefore disabled on such systems. The backport from Linux was really
incomplete, as Linux much earlier had already introduced a dynamcially
allocated memnodemap[].
Further, doing to/from pdx translations on addresses just past a valid
range is not correct, as it may strip/fail to insert non-zero bits in
this case.
Finally, using 63 as the cover-it-all shift value is invalid on 32bit,
since pdx values are unsigned long.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
--- 2010年01月06日.orig/xen/arch/x86/numa.c 2010年01月06日 15:16:18.000000000 +0100
+++ 2010年01月06日/xen/arch/x86/numa.c 2010年01月06日 16:10:59.000000000 +0100
@@ -30,7 +30,9 @@ struct node_data node_data[MAX_NUMNODES]
 
 /* Mapping from pdx to node id */
 int memnode_shift;
-u8 memnodemap[NODEMAPSIZE];
+static typeof(*memnodemap) _memnodemap[2];
+unsigned long memnodemapsize;
+u8 *memnodemap;
 
 unsigned char cpu_to_node[NR_CPUS] __read_mostly = {
 [0 ... NR_CPUS-1] = NUMA_NO_NODE
@@ -62,13 +64,13 @@ static int __init populate_memnodemap(co
 unsigned long spdx, epdx;
 int i, res = -1;
 
- memset(memnodemap, NUMA_NO_NODE, sizeof(memnodemap));
+ memset(memnodemap, NUMA_NO_NODE, memnodemapsize * sizeof(*memnodemap));
 for (i = 0; i < numnodes; i++) {
 spdx = paddr_to_pdx(nodes[i].start);
- epdx = paddr_to_pdx(nodes[i].end);
+ epdx = paddr_to_pdx(nodes[i].end - 1) + 1;
 if (spdx >= epdx)
 continue;
- if ((epdx >> shift) >= NODEMAPSIZE)
+ if ((epdx >> shift) >= memnodemapsize)
 return 0;
 do {
 if (memnodemap[spdx >> shift] != NUMA_NO_NODE)
@@ -86,6 +88,28 @@ static int __init populate_memnodemap(co
 return res;
 }
 
+static int __init allocate_cachealigned_memnodemap(void)
+{
+ unsigned long size = PFN_UP(memnodemapsize * sizeof(*memnodemap));
+ unsigned long mfn = alloc_boot_pages(size, 1);
+
+ if (!mfn) {
+ printk(KERN_ERR
+ "NUMA: Unable to allocate Memory to Node hash map\n");
+ memnodemapsize = 0;
+ return -1;
+ }
+
+ memnodemap = mfn_to_virt(mfn);
+ mfn <<= PAGE_SHIFT;
+ size <<= PAGE_SHIFT;
+ printk(KERN_DEBUG "NUMA: Allocated memnodemap from %lx - %lx\n",
+ mfn, mfn + size);
+ memnodemapsize = size / sizeof(*memnodemap);
+
+ return 0;
+}
+
 /*
 * The LSB of all start and end addresses in the node map is the value of the
 * maximum possible shift.
@@ -99,7 +123,7 @@ static int __init extract_lsb_from_nodes
 
 for (i = 0; i < numnodes; i++) {
 spdx = paddr_to_pdx(nodes[i].start);
- epdx = paddr_to_pdx(nodes[i].end);
+ epdx = paddr_to_pdx(nodes[i].end - 1) + 1;
 if (spdx >= epdx)
 continue;
 bitfield |= spdx;
@@ -108,9 +132,10 @@ static int __init extract_lsb_from_nodes
 memtop = epdx;
 }
 if (nodes_used <= 1)
- i = 63;
+ i = BITS_PER_LONG - 1;
 else
 i = find_first_bit(&bitfield, sizeof(unsigned long)*8);
+ memnodemapsize = (memtop >> i) + 1;
 return i;
 }
 
@@ -120,6 +145,10 @@ int __init compute_hash_shift(struct nod
 int shift;
 
 shift = extract_lsb_from_nodes(nodes, numnodes);
+ if (memnodemapsize <= ARRAY_SIZE(_memnodemap))
+ memnodemap = _memnodemap;
+ else if (allocate_cachealigned_memnodemap())
+ return -1;
 printk(KERN_DEBUG "NUMA: Using %d for the hash shift.\n",
 shift);
 
@@ -233,8 +262,8 @@ void __init numa_initmem_init(unsigned l
 (u64)start_pfn << PAGE_SHIFT,
 (u64)end_pfn << PAGE_SHIFT);
 /* setup dummy node covering all memory */ 
- memnode_shift = 63; 
- memnodemap[0] = 0;
+ memnode_shift = BITS_PER_LONG - 1;
+ memnodemap = _memnodemap;
 nodes_clear(node_online_map);
 node_set_online(0);
 for (i = 0; i < NR_CPUS; i++)
--- 2010年01月06日.orig/xen/include/asm-x86/numa.h 2010年01月06日 15:16:18.000000000 
+0100
+++ 2010年01月06日/xen/include/asm-x86/numa.h 2010年01月06日 15:15:41.000000000 
+0100
@@ -25,7 +25,6 @@ extern int pxm_to_node(int nid);
 
 #define ZONE_ALIGN (1UL << (MAX_ORDER+PAGE_SHIFT))
 #define VIRTUAL_BUG_ON(x) 
-#define NODEMAPSIZE 0xfff
 
 extern void numa_add_cpu(int cpu);
 extern void numa_init_array(void);
@@ -51,7 +50,8 @@ static inline void clear_node_cpumask(in
 
 /* Simple perfect hash to map pdx to node numbers */
 extern int memnode_shift; 
-extern u8 memnodemap[NODEMAPSIZE]; 
+extern unsigned long memnodemapsize;
+extern u8 *memnodemap;
 
 struct node_data {
 unsigned long node_start_pfn;
@@ -64,7 +64,7 @@ extern struct node_data node_data[];
 static inline __attribute__((pure)) int phys_to_nid(paddr_t addr) 
 { 
 unsigned nid;
- VIRTUAL_BUG_ON((paddr_to_pdx(addr) >> memnode_shift) >= NODEMAPSIZE);
+ VIRTUAL_BUG_ON((paddr_to_pdx(addr) >> memnode_shift) >= memnodemapsize);
 nid = memnodemap[paddr_to_pdx(addr) >> memnode_shift]; 
 VIRTUAL_BUG_ON(nid >= MAX_NUMNODES || !node_data[nid]); 
 return nid; 

Attachment: xen-x86-numa-node-map.patch
Description: Text document

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