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authorTejun Heo <tj@kernel.org>2011-02-22 11:10:08 +0100
committerTejun Heo <tj@kernel.org>2011-02-22 11:10:08 +0100
commitb8ef9172b2aad7eeb1fcd37a9e632c7b24da1f64 (patch)
treec63a57e3c392f2d45ba975d29cdd768904ef169f /arch/x86/mm/numa_emulation.c
parentfbe99959d1db85222829a64d869dcab704ac7ec8 (diff)
downloadlinux-b8ef9172b2aad7eeb1fcd37a9e632c7b24da1f64.tar.bz2
x86-64, NUMA: Move NUMA emulation into numa_emulation.c
Create numa_emulation.c and move all NUMA emulation code there. The definitions of struct numa_memblk and numa_meminfo are moved to numa_64.h. Also, numa_remove_memblk_from(), numa_cleanup_meminfo(), numa_reset_distance() along with numa_emulation() are made global. - v2: Internal declarations moved to numa_internal.h as suggested by Yinghai. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Yinghai Lu <yinghai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com>
Diffstat (limited to 'arch/x86/mm/numa_emulation.c')
-rw-r--r--arch/x86/mm/numa_emulation.c452
1 files changed, 452 insertions, 0 deletions
diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c
new file mode 100644
index 000000000000..23fa2d00253a
--- /dev/null
+++ b/arch/x86/mm/numa_emulation.c
@@ -0,0 +1,452 @@
+/*
+ * NUMA emulation
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/topology.h>
+#include <linux/memblock.h>
+#include <asm/dma.h>
+
+#include "numa_internal.h"
+
+static int emu_nid_to_phys[MAX_NUMNODES] __cpuinitdata;
+static char *emu_cmdline __initdata;
+
+void __init numa_emu_cmdline(char *str)
+{
+ emu_cmdline = str;
+}
+
+static int __init emu_find_memblk_by_nid(int nid, const struct numa_meminfo *mi)
+{
+ int i;
+
+ for (i = 0; i < mi->nr_blks; i++)
+ if (mi->blk[i].nid == nid)
+ return i;
+ return -ENOENT;
+}
+
+/*
+ * Sets up nid to range from @start to @end. The return value is -errno if
+ * something went wrong, 0 otherwise.
+ */
+static int __init emu_setup_memblk(struct numa_meminfo *ei,
+ struct numa_meminfo *pi,
+ int nid, int phys_blk, u64 size)
+{
+ struct numa_memblk *eb = &ei->blk[ei->nr_blks];
+ struct numa_memblk *pb = &pi->blk[phys_blk];
+
+ if (ei->nr_blks >= NR_NODE_MEMBLKS) {
+ pr_err("NUMA: Too many emulated memblks, failing emulation\n");
+ return -EINVAL;
+ }
+
+ ei->nr_blks++;
+ eb->start = pb->start;
+ eb->end = pb->start + size;
+ eb->nid = nid;
+
+ if (emu_nid_to_phys[nid] == NUMA_NO_NODE)
+ emu_nid_to_phys[nid] = pb->nid;
+
+ pb->start += size;
+ if (pb->start >= pb->end) {
+ WARN_ON_ONCE(pb->start > pb->end);
+ numa_remove_memblk_from(phys_blk, pi);
+ }
+
+ printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n", nid,
+ eb->start, eb->end, (eb->end - eb->start) >> 20);
+ return 0;
+}
+
+/*
+ * Sets up nr_nodes fake nodes interleaved over physical nodes ranging from addr
+ * to max_addr. The return value is the number of nodes allocated.
+ */
+static int __init split_nodes_interleave(struct numa_meminfo *ei,
+ struct numa_meminfo *pi,
+ u64 addr, u64 max_addr, int nr_nodes)
+{
+ nodemask_t physnode_mask = NODE_MASK_NONE;
+ u64 size;
+ int big;
+ int nid = 0;
+ int i, ret;
+
+ if (nr_nodes <= 0)
+ return -1;
+ if (nr_nodes > MAX_NUMNODES) {
+ pr_info("numa=fake=%d too large, reducing to %d\n",
+ nr_nodes, MAX_NUMNODES);
+ nr_nodes = MAX_NUMNODES;
+ }
+
+ size = (max_addr - addr - memblock_x86_hole_size(addr, max_addr)) / nr_nodes;
+ /*
+ * Calculate the number of big nodes that can be allocated as a result
+ * of consolidating the remainder.
+ */
+ big = ((size & ~FAKE_NODE_MIN_HASH_MASK) * nr_nodes) /
+ FAKE_NODE_MIN_SIZE;
+
+ size &= FAKE_NODE_MIN_HASH_MASK;
+ if (!size) {
+ pr_err("Not enough memory for each node. "
+ "NUMA emulation disabled.\n");
+ return -1;
+ }
+
+ for (i = 0; i < pi->nr_blks; i++)
+ node_set(pi->blk[i].nid, physnode_mask);
+
+ /*
+ * Continue to fill physical nodes with fake nodes until there is no
+ * memory left on any of them.
+ */
+ while (nodes_weight(physnode_mask)) {
+ for_each_node_mask(i, physnode_mask) {
+ u64 dma32_end = PFN_PHYS(MAX_DMA32_PFN);
+ u64 start, limit, end;
+ int phys_blk;
+
+ phys_blk = emu_find_memblk_by_nid(i, pi);
+ if (phys_blk < 0) {
+ node_clear(i, physnode_mask);
+ continue;
+ }
+ start = pi->blk[phys_blk].start;
+ limit = pi->blk[phys_blk].end;
+ end = start + size;
+
+ if (nid < big)
+ end += FAKE_NODE_MIN_SIZE;
+
+ /*
+ * Continue to add memory to this fake node if its
+ * non-reserved memory is less than the per-node size.
+ */
+ while (end - start -
+ memblock_x86_hole_size(start, end) < size) {
+ end += FAKE_NODE_MIN_SIZE;
+ if (end > limit) {
+ end = limit;
+ break;
+ }
+ }
+
+ /*
+ * If there won't be at least FAKE_NODE_MIN_SIZE of
+ * non-reserved memory in ZONE_DMA32 for the next node,
+ * this one must extend to the boundary.
+ */
+ if (end < dma32_end && dma32_end - end -
+ memblock_x86_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE)
+ end = dma32_end;
+
+ /*
+ * If there won't be enough non-reserved memory for the
+ * next node, this one must extend to the end of the
+ * physical node.
+ */
+ if (limit - end -
+ memblock_x86_hole_size(end, limit) < size)
+ end = limit;
+
+ ret = emu_setup_memblk(ei, pi, nid++ % nr_nodes,
+ phys_blk,
+ min(end, limit) - start);
+ if (ret < 0)
+ return ret;
+ }
+ }
+ return 0;
+}
+
+/*
+ * Returns the end address of a node so that there is at least `size' amount of
+ * non-reserved memory or `max_addr' is reached.
+ */
+static u64 __init find_end_of_node(u64 start, u64 max_addr, u64 size)
+{
+ u64 end = start + size;
+
+ while (end - start - memblock_x86_hole_size(start, end) < size) {
+ end += FAKE_NODE_MIN_SIZE;
+ if (end > max_addr) {
+ end = max_addr;
+ break;
+ }
+ }
+ return end;
+}
+
+/*
+ * Sets up fake nodes of `size' interleaved over physical nodes ranging from
+ * `addr' to `max_addr'. The return value is the number of nodes allocated.
+ */
+static int __init split_nodes_size_interleave(struct numa_meminfo *ei,
+ struct numa_meminfo *pi,
+ u64 addr, u64 max_addr, u64 size)
+{
+ nodemask_t physnode_mask = NODE_MASK_NONE;
+ u64 min_size;
+ int nid = 0;
+ int i, ret;
+
+ if (!size)
+ return -1;
+ /*
+ * The limit on emulated nodes is MAX_NUMNODES, so the size per node is
+ * increased accordingly if the requested size is too small. This
+ * creates a uniform distribution of node sizes across the entire
+ * machine (but not necessarily over physical nodes).
+ */
+ min_size = (max_addr - addr - memblock_x86_hole_size(addr, max_addr)) /
+ MAX_NUMNODES;
+ min_size = max(min_size, FAKE_NODE_MIN_SIZE);
+ if ((min_size & FAKE_NODE_MIN_HASH_MASK) < min_size)
+ min_size = (min_size + FAKE_NODE_MIN_SIZE) &
+ FAKE_NODE_MIN_HASH_MASK;
+ if (size < min_size) {
+ pr_err("Fake node size %LuMB too small, increasing to %LuMB\n",
+ size >> 20, min_size >> 20);
+ size = min_size;
+ }
+ size &= FAKE_NODE_MIN_HASH_MASK;
+
+ for (i = 0; i < pi->nr_blks; i++)
+ node_set(pi->blk[i].nid, physnode_mask);
+
+ /*
+ * Fill physical nodes with fake nodes of size until there is no memory
+ * left on any of them.
+ */
+ while (nodes_weight(physnode_mask)) {
+ for_each_node_mask(i, physnode_mask) {
+ u64 dma32_end = MAX_DMA32_PFN << PAGE_SHIFT;
+ u64 start, limit, end;
+ int phys_blk;
+
+ phys_blk = emu_find_memblk_by_nid(i, pi);
+ if (phys_blk < 0) {
+ node_clear(i, physnode_mask);
+ continue;
+ }
+ start = pi->blk[phys_blk].start;
+ limit = pi->blk[phys_blk].end;
+
+ end = find_end_of_node(start, limit, size);
+ /*
+ * If there won't be at least FAKE_NODE_MIN_SIZE of
+ * non-reserved memory in ZONE_DMA32 for the next node,
+ * this one must extend to the boundary.
+ */
+ if (end < dma32_end && dma32_end - end -
+ memblock_x86_hole_size(end, dma32_end) < FAKE_NODE_MIN_SIZE)
+ end = dma32_end;
+
+ /*
+ * If there won't be enough non-reserved memory for the
+ * next node, this one must extend to the end of the
+ * physical node.
+ */
+ if (limit - end -
+ memblock_x86_hole_size(end, limit) < size)
+ end = limit;
+
+ ret = emu_setup_memblk(ei, pi, nid++ % MAX_NUMNODES,
+ phys_blk,
+ min(end, limit) - start);
+ if (ret < 0)
+ return ret;
+ }
+ }
+ return 0;
+}
+
+/*
+ * Sets up the system RAM area from start_pfn to last_pfn according to the
+ * numa=fake command-line option.
+ */
+void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt)
+{
+ static struct numa_meminfo ei __initdata;
+ static struct numa_meminfo pi __initdata;
+ const u64 max_addr = max_pfn << PAGE_SHIFT;
+ u8 *phys_dist = NULL;
+ int i, j, ret;
+
+ if (!emu_cmdline)
+ goto no_emu;
+
+ memset(&ei, 0, sizeof(ei));
+ pi = *numa_meminfo;
+
+ 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,
+ * split the system RAM into N fake nodes.
+ */
+ if (strchr(emu_cmdline, 'M') || strchr(emu_cmdline, 'G')) {
+ u64 size;
+
+ size = memparse(emu_cmdline, &emu_cmdline);
+ ret = split_nodes_size_interleave(&ei, &pi, 0, max_addr, size);
+ } else {
+ unsigned long n;
+
+ n = simple_strtoul(emu_cmdline, NULL, 0);
+ ret = split_nodes_interleave(&ei, &pi, 0, max_addr, n);
+ }
+
+ if (ret < 0)
+ goto no_emu;
+
+ if (numa_cleanup_meminfo(&ei) < 0) {
+ pr_warning("NUMA: Warning: constructed meminfo invalid, disabling emulation\n");
+ goto no_emu;
+ }
+
+ /*
+ * Copy the original distance table. It's temporary so no need to
+ * reserve it.
+ */
+ if (numa_dist_cnt) {
+ size_t size = numa_dist_cnt * sizeof(phys_dist[0]);
+ u64 phys;
+
+ phys = memblock_find_in_range(0,
+ (u64)max_pfn_mapped << PAGE_SHIFT,
+ size, PAGE_SIZE);
+ if (phys == MEMBLOCK_ERROR) {
+ pr_warning("NUMA: Warning: can't allocate copy of distance table, disabling emulation\n");
+ goto no_emu;
+ }
+ phys_dist = __va(phys);
+
+ for (i = 0; i < numa_dist_cnt; i++)
+ for (j = 0; j < numa_dist_cnt; j++)
+ phys_dist[i * numa_dist_cnt + j] =
+ node_distance(i, j);
+ }
+
+ /* commit */
+ *numa_meminfo = ei;
+
+ /*
+ * Transform __apicid_to_node table to use emulated nids by
+ * reverse-mapping phys_nid. The maps should always exist but fall
+ * back to zero just in case.
+ */
+ for (i = 0; i < ARRAY_SIZE(__apicid_to_node); i++) {
+ if (__apicid_to_node[i] == NUMA_NO_NODE)
+ continue;
+ for (j = 0; j < ARRAY_SIZE(emu_nid_to_phys); j++)
+ if (__apicid_to_node[i] == emu_nid_to_phys[j])
+ break;
+ __apicid_to_node[i] = j < ARRAY_SIZE(emu_nid_to_phys) ? j : 0;
+ }
+
+ /* 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;
+
+ /* transform distance table */
+ numa_reset_distance();
+ for (i = 0; i < MAX_NUMNODES; i++) {
+ for (j = 0; j < MAX_NUMNODES; j++) {
+ int physi = emu_nid_to_phys[i];
+ int physj = emu_nid_to_phys[j];
+ int dist;
+
+ if (physi >= numa_dist_cnt || physj >= numa_dist_cnt)
+ dist = physi == physj ?
+ LOCAL_DISTANCE : REMOTE_DISTANCE;
+ else
+ dist = phys_dist[physi * numa_dist_cnt + physj];
+
+ numa_set_distance(i, j, dist);
+ }
+ }
+ return;
+
+no_emu:
+ /* No emulation. Build identity emu_nid_to_phys[] for numa_add_cpu() */
+ for (i = 0; i < ARRAY_SIZE(emu_nid_to_phys); i++)
+ emu_nid_to_phys[i] = i;
+}
+
+#ifndef CONFIG_DEBUG_PER_CPU_MAPS
+void __cpuinit numa_add_cpu(int cpu)
+{
+ int physnid, nid;
+
+ nid = numa_cpu_node(cpu);
+ if (nid == NUMA_NO_NODE)
+ nid = early_cpu_to_node(cpu);
+ BUG_ON(nid == NUMA_NO_NODE || !node_online(nid));
+
+ 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)
+ if (emu_nid_to_phys[nid] == physnid)
+ cpumask_set_cpu(cpu, node_to_cpumask_map[nid]);
+}
+
+void __cpuinit numa_remove_cpu(int cpu)
+{
+ int i;
+
+ for_each_online_node(i)
+ cpumask_clear_cpu(cpu, node_to_cpumask_map[i]);
+}
+#else /* !CONFIG_DEBUG_PER_CPU_MAPS */
+static void __cpuinit numa_set_cpumask(int cpu, int enable)
+{
+ struct cpumask *mask;
+ int nid, physnid, i;
+
+ nid = early_cpu_to_node(cpu);
+ if (nid == NUMA_NO_NODE) {
+ /* early_cpu_to_node() already emits a warning and trace */
+ return;
+ }
+
+ 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;
+
+ if (enable)
+ cpumask_set_cpu(cpu, mask);
+ else
+ cpumask_clear_cpu(cpu, mask);
+ }
+}
+
+void __cpuinit numa_add_cpu(int cpu)
+{
+ numa_set_cpumask(cpu, 1);
+}
+
+void __cpuinit numa_remove_cpu(int cpu)
+{
+ numa_set_cpumask(cpu, 0);
+}
+#endif /* !CONFIG_DEBUG_PER_CPU_MAPS */