Commit 5c3f5892 authored by Balbir Singh's avatar Balbir Singh Committed by Paul Mackerras
Browse files

[POWERPC] Fake NUMA emulation for PowerPC 



Here's a dumb simple implementation of fake NUMA nodes for PowerPC.
Fake NUMA nodes can be specified using the following command line option

numa=fake=<node range>

node range is of the format <range1>,<range2>,...<rangeN>

Each of the rangeX parameters is passed using memparse().  I find this
useful for fake NUMA emulation on my simple PowerPC machine.  I've
tested it on a non-numa box with the following arguments:

numa=fake=1G
numa=fake=1G,2G
name=fake=1G,512M,2G
numa=fake=1500M,2800M mem=3500M
numa=fake=1G mem=512M
numa=fake=1G mem=1G

Signed-off-by: default avatarBalbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 800d68c3

arch/powerpc/mm/numa.c

+54 −5
Original line number Diff line number Diff line
@@ -24,6 +24,8 @@ 


static int numa_enabled = 1;



static char *cmdline __initdata;



static int numa_debug;

#define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }
@@ -39,6 +41,43 @@ static bootmem_data_t __initdata plat_node_bdata[MAX_NUMNODES]; 
static int min_common_depth;

static int n_mem_addr_cells, n_mem_size_cells;



static int __cpuinit fake_numa_create_new_node(unsigned long end_pfn,

						unsigned int *nid)

{

	unsigned long long mem;

	char *p = cmdline;

	static unsigned int fake_nid = 0;

	static unsigned long long curr_boundary = 0;



	*nid = fake_nid;

	if (!p)

		return 0;



	mem = memparse(p, &p);

	if (!mem)

		return 0;



	if (mem < curr_boundary)

		return 0;



	curr_boundary = mem;



	if ((end_pfn << PAGE_SHIFT) > mem) {

		/*

		 * Skip commas and spaces

		 */

		while (*p == ',' || *p == ' ' || *p == '\t')

			p++;



		cmdline = p;

		fake_nid++;

		*nid = fake_nid;

		dbg("created new fake_node with id %d\n", fake_nid);

		return 1;

	}

	return 0;

}



static void __cpuinit map_cpu_to_node(int cpu, int node)

{

	numa_cpu_lookup_table[cpu] = node;
@@ -344,12 +383,14 @@ static void __init parse_drconf_memory(struct device_node *memory) 
			if (nid == 0xffff || nid >= MAX_NUMNODES)

				nid = default_nid;

		}

		node_set_online(nid);



		size = numa_enforce_memory_limit(start, lmb_size);

		if (!size)

			continue;



		fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);

		node_set_online(nid);



		add_active_range(nid, start >> PAGE_SHIFT,

				 (start >> PAGE_SHIFT) + (size >> PAGE_SHIFT));

	}
@@ -429,7 +470,6 @@ new_range: 
		nid = of_node_to_nid_single(memory);

		if (nid < 0)

			nid = default_nid;

		node_set_online(nid);



		if (!(size = numa_enforce_memory_limit(start, size))) {

			if (--ranges)
@@ -438,6 +478,9 @@ new_range: 
				continue;

		}



		fake_numa_create_new_node(((start + size) >> PAGE_SHIFT), &nid);

		node_set_online(nid);



		add_active_range(nid, start >> PAGE_SHIFT,

				(start >> PAGE_SHIFT) + (size >> PAGE_SHIFT));
@@ -461,7 +504,7 @@ static void __init setup_nonnuma(void) 
	unsigned long top_of_ram = lmb_end_of_DRAM();

	unsigned long total_ram = lmb_phys_mem_size();

	unsigned long start_pfn, end_pfn;

	unsigned int i;

	unsigned int i, nid = 0;



	printk(KERN_DEBUG "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",

	       top_of_ram, total_ram);
@@ -471,9 +514,11 @@ static void __init setup_nonnuma(void) 
	for (i = 0; i < lmb.memory.cnt; ++i) {

		start_pfn = lmb.memory.region[i].base >> PAGE_SHIFT;

		end_pfn = start_pfn + lmb_size_pages(&lmb.memory, i);

		add_active_range(0, start_pfn, end_pfn);



		fake_numa_create_new_node(end_pfn, &nid);

		add_active_range(nid, start_pfn, end_pfn);

		node_set_online(nid);

	}

	node_set_online(0);

}



void __init dump_numa_cpu_topology(void)
@@ -702,6 +747,10 @@ static int __init early_numa(char *p) 
	if (strstr(p, "debug"))

		numa_debug = 1;



	p = strstr(p, "fake=");

	if (p)

		cmdline = p + strlen("fake=");



	return 0;

}

early_param("numa", early_numa);

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