[PATCH 28/33] x86-64, NUMA: Build and use direct emulated nid -> phys nid mapping

Tejun Heo
2011-02-16T12:23:50Z

NUMA emulation copied physical NUMA configuration into physnodes[] and
used it to reverse-map emulated nodes to physical nodes, which is
unnecessarily convoluted. Build emu_nid_to_phys[] array to map
emulated nids directly to the matching physical nids and use it in
numa_add_cpu().

physnodes[] will be removed with further patches.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Shaohui Zheng <shaohui.zheng@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: H. Peter Anvin <hpa@linux.intel.com>
---
arch/x86/mm/numa_64.c | 64 ++++++++++++++++++++++++++----------------------
1 files changed, 35 insertions(+), 29 deletions(-)

diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c
index 20e2cfe..98bf8ba 100644
--- a/arch/x86/mm/numa_64.c
+++ b/arch/x86/mm/numa_64.c
@@ -542,7 +542,9 @@ static int __init numa_register_memblks(struct numa_meminfo *mi)
#ifdef CONFIG_NUMA_EMU
/* Numa emulation */
static struct bootnode nodes[MAX_NUMNODES] __initdata;
-static struct bootnode physnodes[MAX_NUMNODES] __cpuinitdata;
+static struct bootnode physnodes[MAX_NUMNODES] __initdata;
+
+static int emu_nid_to_phys[MAX_NUMNODES] __cpuinitdata;
static char *emu_cmdline __initdata;

void __init numa_emu_cmdline(char *str)
@@ -649,7 +651,8 @@ static void __init fake_physnodes(int acpi, int amd, int nr_nodes)
* allocation past addr and -1 otherwise. addr is adjusted to be at
* the end of the node.
*/
-static int __init setup_node_range(int nid, u64 *addr, u64 size, u64 max_addr)
+static int __init setup_node_range(int nid, int physnid,
+ u64 *addr, u64 size, u64 max_addr)
{
int ret = 0;
nodes[nid].start = *addr;
@@ -660,6 +663,10 @@ static int __init setup_node_range(int nid, u64 *addr, u64 size, u64 max_addr)
}
nodes[nid].end = *addr;
node_set(nid, node_possible_map);
+
+ if (emu_nid_to_phys[nid] == NUMA_NO_NODE)
+ emu_nid_to_phys[nid] = physnid;
+
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);
@@ -756,7 +763,7 @@ static int __init split_nodes_interleave(u64 addr, u64 max_addr, int nr_nodes)
if (nodes_weight(physnode_mask) + ret >= nr_nodes)
end = physnodes[i].end;

- if (setup_node_range(ret++, &physnodes[i].start,
+ if (setup_node_range(ret++, i, &physnodes[i].start,
end - physnodes[i].start,
physnodes[i].end) < 0)
node_clear(i, physnode_mask);
@@ -852,7 +859,7 @@ static int __init split_nodes_size_interleave(u64 addr, u64 max_addr, u64 size)
* later. If setup_node_range() returns non-zero, there
* is no more memory available on this physical node.
*/
- if (setup_node_range(ret++, &physnodes[i].start,
+ if (setup_node_range(ret++, i, &physnodes[i].start,
end - physnodes[i].start,
physnodes[i].end) < 0)
node_clear(i, physnode_mask);
@@ -872,6 +879,9 @@ static int __init numa_emulation(int acpi, int amd)
int num_nodes;
int i;

+ for (i = 0; i < MAX_NUMNODES; i++)
+ emu_nid_to_phys[i] = NUMA_NO_NODE;
+
/*
* If the numa=fake command-line contains a 'M' or 'G', it represents
* the fixed node size. Otherwise, if it is just a single number N,
@@ -892,6 +902,11 @@ static int __init numa_emulation(int acpi, int amd)
if (num_nodes < 0)
return num_nodes;

+ /* make sure all emulated nodes are mapped to a physical node */
+ for (i = 0; i < ARRAY_SIZE(emu_nid_to_phys); i++)
+ if (emu_nid_to_phys[i] == NUMA_NO_NODE)
+ emu_nid_to_phys[i] = 0;
+
ei.nr_blks = num_nodes;
for (i = 0; i < ei.nr_blks; i++) {
ei.blk[i].start = nodes[i].start;
@@ -918,7 +933,6 @@ static int __init numa_emulation(int acpi, int amd)
init_memory_mapping_high();
for_each_node_mask(i, node_possible_map)
setup_node_bootmem(i, nodes[i].start, nodes[i].end);
- setup_physnodes(0, max_addr);
fake_physnodes(acpi, amd, num_nodes);
numa_init_array();
numa_emu_dist = true;
@@ -976,7 +990,11 @@ void __init initmem_init(void)
setup_physnodes(0, max_pfn << PAGE_SHIFT);
if (emu_cmdline && !numa_emulation(i == 0, i == 1))
return;
- setup_physnodes(0, max_pfn << PAGE_SHIFT);
+
+ /* not emulating, build identity mapping for numa_add_cpu() */
+ for (j = 0; j < ARRAY_SIZE(emu_nid_to_phys); j++)
+ emu_nid_to_phys[j] = j;
+
nodes_clear(node_possible_map);
nodes_clear(node_online_map);
#endif
@@ -1033,7 +1051,6 @@ int __cpuinit numa_cpu_node(int cpu)
# ifndef CONFIG_DEBUG_PER_CPU_MAPS
void __cpuinit numa_add_cpu(int cpu)
{
- unsigned long addr;
int physnid, nid;

nid = numa_cpu_node(cpu);
@@ -1041,26 +1058,15 @@ void __cpuinit numa_add_cpu(int cpu)
nid = early_cpu_to_node(cpu);
BUG_ON(nid == NUMA_NO_NODE || !node_online(nid));

- /*
- * Use the starting address of the emulated node to find which physical
- * node it is allocated on.
- */
- addr = node_start_pfn(nid) << PAGE_SHIFT;
- for (physnid = 0; physnid < MAX_NUMNODES; physnid++)
- if (addr >= physnodes[physnid].start &&
- addr < physnodes[physnid].end)
- break;
+ physnid = emu_nid_to_phys[nid];

/*
* Map the cpu to each emulated node that is allocated on the physical
* node of the cpu's apic id.
*/
- for_each_online_node(nid) {
- addr = node_start_pfn(nid) << PAGE_SHIFT;
- if (addr >= physnodes[physnid].start &&
- addr < physnodes[physnid].end)
+ for_each_online_node(nid)
+ if (emu_nid_to_phys[nid] == physnid)
cpumask_set_cpu(cpu, node_to_cpumask_map[nid]);
- }
}

void __cpuinit numa_remove_cpu(int cpu)
@@ -1073,21 +1079,21 @@ void __cpuinit numa_remove_cpu(int cpu)
# else /* !CONFIG_DEBUG_PER_CPU_MAPS */
static void __cpuinit numa_set_cpumask(int cpu, int enable)
{
- int node = early_cpu_to_node(cpu);
struct cpumask *mask;
- int i;
+ int nid, i;

- if (node == NUMA_NO_NODE) {
+ nid = early_cpu_to_node(cpu);
+ if (nid == NUMA_NO_NODE) {
/* early_cpu_to_node() already emits a warning and trace */
return;
}
- for_each_online_node(i) {
- unsigned long addr;

- addr = node_start_pfn(i) << PAGE_SHIFT;
- if (addr < physnodes[node].start ||
- addr >= physnodes[node].end)
+ physnid = emu_nid_to_phys[nid];
+
+ for_each_online_node(i) {
+ if (emu_nid_to_phys[nid] != physnid)
continue;
+
mask = debug_cpumask_set_cpu(cpu, enable);
if (!mask)
return;
--
1.7.1