lkml.org 
[lkml]   [2007]   [Jan]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[patch -mm 1/5] x86_64: configurable fake numa node sizes
Extends the numa=fake x86_64 command-line option to allow for configurable
node sizes. These nodes can be used in conjunction with cpusets for
coarse memory resource management.

The old command-line option is still supported:
numa=fake=32 gives 32 fake NUMA nodes, ignoring the NUMA setup of the
actual machine.

But now you may configure your system for the node sizes of your choice:
numa=fake=2*512,1024,2*256
gives two 512M nodes, one 1024M node, two 256M nodes, and
the rest of system memory to a sixth node.

Cc: Andi Kleen <ak@suse.de>
Signed-off-by: David Rientjes <rientjes@cs.washington.edu>
---
Documentation/x86_64/boot-options.txt | 9 +-
arch/x86_64/mm/numa.c | 249 +++++++++++++++++++--------------
include/asm-x86_64/mmzone.h | 2 +-
3 files changed, 150 insertions(+), 110 deletions(-)
diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt
index 625a21d..6ccdb5e 100644
--- a/Documentation/x86_64/boot-options.txt
+++ b/Documentation/x86_64/boot-options.txt
@@ -149,7 +149,14 @@ 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. If
+ the last character of CMDLINE is a comma, the remaining system
+ memory is not allocated to an additional node.

numa=hotadd=percent
Only allow hotadd memory to preallocate page structures upto
diff --git a/arch/x86_64/mm/numa.c b/arch/x86_64/mm/numa.c
index 9ff3141..0417921 100644
--- a/arch/x86_64/mm/numa.c
+++ b/arch/x86_64/mm/numa.c
@@ -276,125 +276,160 @@ 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 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 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 (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 = (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 && *(cmdline - 1) != ',') {
+ 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;
+ }
+ 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);
@@ -402,14 +437,15 @@ static int __init numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
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

@@ -502,11 +538,8 @@ 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))
diff --git a/include/asm-x86_64/mmzone.h b/include/asm-x86_64/mmzone.h
index fb558fb..19a8937 100644
--- a/include/asm-x86_64/mmzone.h
+++ b/include/asm-x86_64/mmzone.h
@@ -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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2007-01-25 22:41    [W:1.197 / U:0.296 seconds]
©2003-2014 Jasper Spaans. Advertise on this site