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r: 53794
b: refs/heads/master
c: 8b8ca80
h: refs/heads/master
v: v3
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David Rientjes authored and Andi Kleen committed May 2, 2007
1 parent 6c9c943 commit a28a353
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Showing 4 changed files with 162 additions and 111 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 8280c0c58e9762a9fe29d550a9db81410de77691
refs/heads/master: 8b8ca80e192b10eecc01fc44a2902510af86f73b
8 changes: 7 additions & 1 deletion trunk/Documentation/x86_64/boot-options.txt
Original file line number Diff line number Diff line change
Expand Up @@ -149,7 +149,13 @@ NUMA

numa=noacpi Don't parse the SRAT table for NUMA setup

numa=fake=X Fake X nodes and ignore NUMA setup of the actual machine.
numa=fake=CMDLINE
If a number, fakes CMDLINE nodes and ignores NUMA setup of the
actual machine. Otherwise, system memory is configured
depending on the sizes and coefficients listed. For example:
numa=fake=2*512,1024,4*256
gives two 512M nodes, a 1024M node, and four 256M nodes. The
remaining system RAM is allocated to an additional node.

numa=hotadd=percent
Only allow hotadd memory to preallocate page structures upto
Expand Down
261 changes: 153 additions & 108 deletions trunk/arch/x86_64/mm/numa.c
Original file line number Diff line number Diff line change
Expand Up @@ -273,140 +273,188 @@ void __init numa_init_array(void)

#ifdef CONFIG_NUMA_EMU
/* Numa emulation */
int numa_fake __initdata = 0;
#define E820_ADDR_HOLE_SIZE(start, end) \
(e820_hole_size((start) >> PAGE_SHIFT, (end) >> PAGE_SHIFT) << \
PAGE_SHIFT)
char *cmdline __initdata;

/*
* This function is used to find out if the start and end correspond to
* different zones.
* Setups up nid to range from addr to addr + size. If the end boundary is
* greater than max_addr, then max_addr is used instead. The return value is 0
* if there is additional memory left for allocation past addr and -1 otherwise.
* addr is adjusted to be at the end of the node.
*/
int zone_cross_over(unsigned long start, unsigned long end)
static int __init setup_node_range(int nid, struct bootnode *nodes, u64 *addr,
u64 size, u64 max_addr)
{
if ((start < (MAX_DMA32_PFN << PAGE_SHIFT)) &&
(end >= (MAX_DMA32_PFN << PAGE_SHIFT)))
return 1;
return 0;
int ret = 0;
nodes[nid].start = *addr;
*addr += size;
if (*addr >= max_addr) {
*addr = max_addr;
ret = -1;
}
nodes[nid].end = *addr;
node_set_online(nid);
printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n", nid,
nodes[nid].start, nodes[nid].end,
(nodes[nid].end - nodes[nid].start) >> 20);
return ret;
}

static int __init numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
/*
* Splits num_nodes nodes up equally starting at node_start. The return value
* is the number of nodes split up and addr is adjusted to be at the end of the
* last node allocated.
*/
static int __init split_nodes_equally(struct bootnode *nodes, u64 *addr,
u64 max_addr, int node_start,
int num_nodes)
{
int i, big;
struct bootnode nodes[MAX_NUMNODES];
unsigned long sz, old_sz;
unsigned long hole_size;
unsigned long start, end;
unsigned long max_addr = (end_pfn << PAGE_SHIFT);

start = (start_pfn << PAGE_SHIFT);
hole_size = e820_hole_size(start, max_addr);
sz = (max_addr - start - hole_size) / numa_fake;

/* Kludge needed for the hash function */

old_sz = sz;
/*
* Round down to the nearest FAKE_NODE_MIN_SIZE.
*/
sz &= FAKE_NODE_MIN_HASH_MASK;
unsigned int big;
u64 size;
int i;

if (num_nodes <= 0)
return -1;
if (num_nodes > MAX_NUMNODES)
num_nodes = MAX_NUMNODES;
size = (max_addr - *addr - E820_ADDR_HOLE_SIZE(*addr, max_addr)) /
num_nodes;
/*
* We ensure that each node is at least 64MB big. Smaller than this
* size can cause VM hiccups.
* Calculate the number of big nodes that can be allocated as a result
* of consolidating the leftovers.
*/
if (sz == 0) {
printk(KERN_INFO "Not enough memory for %d nodes. Reducing "
"the number of nodes\n", numa_fake);
numa_fake = (max_addr - start - hole_size) / FAKE_NODE_MIN_SIZE;
printk(KERN_INFO "Number of fake nodes will be = %d\n",
numa_fake);
sz = FAKE_NODE_MIN_SIZE;
big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * num_nodes) /
FAKE_NODE_MIN_SIZE;

/* Round down to nearest FAKE_NODE_MIN_SIZE. */
size &= FAKE_NODE_MIN_HASH_MASK;
if (!size) {
printk(KERN_ERR "Not enough memory for each node. "
"NUMA emulation disabled.\n");
return -1;
}
/*
* Find out how many nodes can get an extra NODE_MIN_SIZE granule.
* This logic ensures the extra memory gets distributed among as many
* nodes as possible (as compared to one single node getting all that
* extra memory.
*/
big = ((old_sz - sz) * numa_fake) / FAKE_NODE_MIN_SIZE;
printk(KERN_INFO "Fake node Size: %luMB hole_size: %luMB big nodes: "
"%d\n",
(sz >> 20), (hole_size >> 20), big);
memset(&nodes,0,sizeof(nodes));
end = start;
for (i = 0; i < numa_fake; i++) {
/*
* In case we are not able to allocate enough memory for all
* the nodes, we reduce the number of fake nodes.
*/
if (end >= max_addr) {
numa_fake = i - 1;
break;
}
start = nodes[i].start = end;
/*
* Final node can have all the remaining memory.
*/
if (i == numa_fake-1)
sz = max_addr - start;
end = nodes[i].start + sz;
/*
* Fir "big" number of nodes get extra granule.
*/

for (i = node_start; i < num_nodes + node_start; i++) {
u64 end = *addr + size;
if (i < big)
end += FAKE_NODE_MIN_SIZE;
/*
* Iterate over the range to ensure that this node gets at
* least sz amount of RAM (excluding holes)
* The final node can have the remaining system RAM. Other
* nodes receive roughly the same amount of available pages.
*/
while ((end - start - e820_hole_size(start, end)) < sz) {
end += FAKE_NODE_MIN_SIZE;
if (end >= max_addr)
break;
if (i == num_nodes + node_start - 1)
end = max_addr;
else
while (end - *addr - E820_ADDR_HOLE_SIZE(*addr, end) <
size) {
end += FAKE_NODE_MIN_SIZE;
if (end > max_addr) {
end = max_addr;
break;
}
}
if (setup_node_range(i, nodes, addr, end - *addr, max_addr) < 0)
break;
}
return i - node_start + 1;
}

/*
* Sets up the system RAM area from start_pfn to end_pfn according to the
* numa=fake command-line option.
*/
static int __init numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
{
struct bootnode nodes[MAX_NUMNODES];
u64 addr = start_pfn << PAGE_SHIFT;
u64 max_addr = end_pfn << PAGE_SHIFT;
unsigned int coeff;
unsigned int num = 0;
int num_nodes = 0;
u64 size;
int i;

memset(&nodes, 0, sizeof(nodes));
/*
* If the numa=fake command-line is just a single number N, split the
* system RAM into N fake nodes.
*/
if (!strchr(cmdline, '*') && !strchr(cmdline, ',')) {
num_nodes = split_nodes_equally(nodes, &addr, max_addr, 0,
simple_strtol(cmdline, NULL, 0));
if (num_nodes < 0)
return num_nodes;
goto out;
}

/* Parse the command line. */
for (coeff = 1; ; cmdline++) {
if (*cmdline && isdigit(*cmdline)) {
num = num * 10 + *cmdline - '0';
continue;
}
/*
* Look at the next node to make sure there is some real memory
* to map. Bad things happen when the only memory present
* in a zone on a fake node is IO hole.
*/
while (e820_hole_size(end, end + FAKE_NODE_MIN_SIZE) > 0) {
if (zone_cross_over(start, end + sz)) {
end = (MAX_DMA32_PFN << PAGE_SHIFT);
break;
if (*cmdline == '*')
coeff = num;
if (!*cmdline || *cmdline == ',') {
/*
* Round down to the nearest FAKE_NODE_MIN_SIZE.
* Command-line coefficients are in megabytes.
*/
size = ((u64)num << 20) & FAKE_NODE_MIN_HASH_MASK;
if (size) {
for (i = 0; i < coeff; i++, num_nodes++)
if (setup_node_range(num_nodes, nodes,
&addr, size, max_addr) < 0)
goto done;
coeff = 1;
}
if (end >= max_addr)
break;
end += FAKE_NODE_MIN_SIZE;
}
if (end > max_addr)
end = max_addr;
nodes[i].end = end;
printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n",
i,
nodes[i].start, nodes[i].end,
(nodes[i].end - nodes[i].start) >> 20);
node_set_online(i);
}
memnode_shift = compute_hash_shift(nodes, numa_fake);
if (memnode_shift < 0) {
memnode_shift = 0;
printk(KERN_ERR "No NUMA hash function found. Emulation disabled.\n");
return -1;
}
for_each_online_node(i) {
if (!*cmdline)
break;
num = 0;
}
done:
if (!num_nodes)
return -1;
/* Fill remainder of system RAM with a final node, if appropriate. */
if (addr < max_addr) {
setup_node_range(num_nodes, nodes, &addr, max_addr - addr,
max_addr);
num_nodes++;
}
out:
memnode_shift = compute_hash_shift(nodes, num_nodes);
if (memnode_shift < 0) {
memnode_shift = 0;
printk(KERN_ERR "No NUMA hash function found. NUMA emulation "
"disabled.\n");
return -1;
}

/*
* We need to vacate all active ranges that may have been registered by
* SRAT.
*/
remove_all_active_ranges();
for_each_online_node(i) {
e820_register_active_regions(i, nodes[i].start >> PAGE_SHIFT,
nodes[i].end >> PAGE_SHIFT);
setup_node_bootmem(i, nodes[i].start, nodes[i].end);
}
numa_init_array();
return 0;
}
#endif
#undef E820_ADDR_HOLE_SIZE
#endif /* CONFIG_NUMA_EMU */

void __init numa_initmem_init(unsigned long start_pfn, unsigned long end_pfn)
{
int i;

#ifdef CONFIG_NUMA_EMU
if (numa_fake && !numa_emulation(start_pfn, end_pfn))
if (cmdline && !numa_emulation(start_pfn, end_pfn))
return;
#endif

Expand Down Expand Up @@ -486,11 +534,8 @@ static __init int numa_setup(char *opt)
if (!strncmp(opt,"off",3))
numa_off = 1;
#ifdef CONFIG_NUMA_EMU
if(!strncmp(opt, "fake=", 5)) {
numa_fake = simple_strtoul(opt+5,NULL,0); ;
if (numa_fake >= MAX_NUMNODES)
numa_fake = MAX_NUMNODES;
}
if (!strncmp(opt, "fake=", 5))
cmdline = opt + 5;
#endif
#ifdef CONFIG_ACPI_NUMA
if (!strncmp(opt,"noacpi",6))
Expand Down
2 changes: 1 addition & 1 deletion trunk/include/asm-x86_64/mmzone.h
Original file line number Diff line number Diff line change
Expand Up @@ -49,7 +49,7 @@ extern int pfn_valid(unsigned long pfn);

#ifdef CONFIG_NUMA_EMU
#define FAKE_NODE_MIN_SIZE (64*1024*1024)
#define FAKE_NODE_MIN_HASH_MASK (~(FAKE_NODE_MIN_SIZE - 1ul))
#define FAKE_NODE_MIN_HASH_MASK (~(FAKE_NODE_MIN_SIZE - 1uL))
#endif

#endif
Expand Down

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