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x86: Add NUMA nodes into CPU topology.

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Depending on hardware, NUMA nodes may match last level caches, or
they may be above them (AMD Zen 2/3) or below (Intel Xeon w/ SNC).
This information is provided by ACPI instead of CPUID, and it is
provided for each CPU individually instead of mask widths, but
this code should be able to properly handle all the above cases.

This change should immediately allow idle stealing in sched_ule(4)
to prefer load from NUMA-local CPUs to remote ones when the node
does not match LLC.  Later we may think of how to better handle it
on sched_pickcpu() side.

MFC after:	1 month
This commit is contained in:
Alexander Motin 2021-09-23 13:41:02 -04:00
parent 1ca931a540
commit ef50d5fbc3
3 changed files with 73 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
sys/kern/sched_ule.c
View File

@ -3098,6 +3098,8 @@ sysctl_kern_sched_topology_spec_internal(struct sbuf *sb, struct cpu_group *cg,
sbuf_printf(sb, "<flag name=\"THREAD\">THREAD group</flag>");
if ((cg->cg_flags & CG_FLAG_SMT) != 0)
sbuf_printf(sb, "<flag name=\"SMT\">SMT group</flag>");
if ((cg->cg_flags & CG_FLAG_NODE) != 0)
sbuf_printf(sb, "<flag name=\"NODE\">NUMA node</flag>");
sbuf_printf(sb, "</flags>\n");
}

1
sys/sys/smp.h
View File

@ -107,6 +107,7 @@ typedef struct cpu_group *cpu_group_t;
#define CG_FLAG_HTT 0x01 /* Schedule the alternate core last. */
#define CG_FLAG_SMT 0x02 /* New age htt, less crippled. */
#define CG_FLAG_THREAD (CG_FLAG_HTT | CG_FLAG_SMT) /* Any threading. */
#define CG_FLAG_NODE 0x04 /* NUMA node. */
/*
* Convenience routines for building and traversing topologies.

84
sys/x86/x86/mp_x86.c
View File

@ -27,6 +27,7 @@
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_acpi.h"
#ifdef __i386__
#include "opt_apic.h"
#endif
@ -83,6 +84,11 @@ __FBSDID("$FreeBSD$");
#include <machine/stack.h>
#include <x86/ucode.h>
#ifdef DEV_ACPI
#include <contrib/dev/acpica/include/acpi.h>
#include <dev/acpica/acpivar.h>
#endif
static MALLOC_DEFINE(M_CPUS, "cpus", "CPU items");
/* lock region used by kernel profiling */
@ -502,13 +508,16 @@ topo_probe(void)
int type;
int subtype;
int id_shift;
} topo_layers[MAX_CACHE_LEVELS + 4];
} topo_layers[MAX_CACHE_LEVELS + 5];
struct topo_node *parent;
struct topo_node *node;
int layer;
int nlayers;
int node_id;
int i;
#if defined(DEV_ACPI) && MAXMEMDOM > 1
int d, domain;
#endif
if (cpu_topo_probed)
return;
@ -583,6 +592,31 @@ topo_probe(void)
topo_layers[nlayers].id_shift = 0;
nlayers++;
#if defined(DEV_ACPI) && MAXMEMDOM > 1
if (vm_ndomains > 1) {
for (layer = 0; layer < nlayers; ++layer) {
for (i = 0; i <= max_apic_id; ++i) {
if ((i & ((1 << topo_layers[layer].id_shift) - 1)) == 0)
domain = -1;
if (!cpu_info[i].cpu_present)
continue;
d = acpi_pxm_get_cpu_locality(i);
if (domain >= 0 && domain != d)
break;
domain = d;
}
if (i > max_apic_id)
break;
}
KASSERT(layer < nlayers, ("NUMA domain smaller than PU"));
memmove(&topo_layers[layer+1], &topo_layers[layer],
sizeof(*topo_layers) * (nlayers - layer));
topo_layers[layer].type = TOPO_TYPE_NODE;
topo_layers[layer].subtype = CG_SHARE_NONE;
nlayers++;
}
#endif
topo_init_root(&topo_root);
for (i = 0; i <= max_apic_id; ++i) {
if (!cpu_info[i].cpu_present)
@ -590,7 +624,12 @@ topo_probe(void)
parent = &topo_root;
for (layer = 0; layer < nlayers; ++layer) {
node_id = i >> topo_layers[layer].id_shift;
#if defined(DEV_ACPI) && MAXMEMDOM > 1
if (topo_layers[layer].type == TOPO_TYPE_NODE) {
node_id = acpi_pxm_get_cpu_locality(i);
} else
#endif
node_id = i >> topo_layers[layer].id_shift;
parent = topo_add_node_by_hwid(parent, node_id,
topo_layers[layer].type,
topo_layers[layer].subtype);
@ -599,7 +638,12 @@ topo_probe(void)
parent = &topo_root;
for (layer = 0; layer < nlayers; ++layer) {
node_id = boot_cpu_id >> topo_layers[layer].id_shift;
#if defined(DEV_ACPI) && MAXMEMDOM > 1
if (topo_layers[layer].type == TOPO_TYPE_NODE)
node_id = acpi_pxm_get_cpu_locality(boot_cpu_id);
else
#endif
node_id = boot_cpu_id >> topo_layers[layer].id_shift;
node = topo_find_node_by_hwid(parent, node_id,
topo_layers[layer].type,
topo_layers[layer].subtype);
@ -774,14 +818,18 @@ x86topo_add_sched_group(struct topo_node *root, struct cpu_group *cg_root)
int i;
KASSERT(root->type == TOPO_TYPE_SYSTEM || root->type == TOPO_TYPE_CACHE ||
root->type == TOPO_TYPE_GROUP,
root->type == TOPO_TYPE_NODE || root->type == TOPO_TYPE_GROUP,
("x86topo_add_sched_group: bad type: %u", root->type));
CPU_COPY(&root->cpuset, &cg_root->cg_mask);
cg_root->cg_count = root->cpu_count;
if (root->type == TOPO_TYPE_SYSTEM)
cg_root->cg_level = CG_SHARE_NONE;
else
if (root->type == TOPO_TYPE_CACHE)
cg_root->cg_level = root->subtype;
else
cg_root->cg_level = CG_SHARE_NONE;
if (root->type == TOPO_TYPE_NODE)
cg_root->cg_flags = CG_FLAG_NODE;
else
cg_root->cg_flags = 0;
/*
* Check how many core nodes we have under the given root node.
@ -802,7 +850,7 @@ x86topo_add_sched_group(struct topo_node *root, struct cpu_group *cg_root)
if (cg_root->cg_level != CG_SHARE_NONE &&
root->cpu_count > 1 && ncores < 2)
cg_root->cg_flags = CG_FLAG_SMT;
cg_root->cg_flags |= CG_FLAG_SMT;
/*
* Find out how many cache nodes we have under the given root node.
@ -814,10 +862,18 @@ x86topo_add_sched_group(struct topo_node *root, struct cpu_group *cg_root)
nchildren = 0;
node = root;
while (node != NULL) {
if ((node->type != TOPO_TYPE_GROUP &&
node->type != TOPO_TYPE_CACHE) ||
(root->type != TOPO_TYPE_SYSTEM &&
CPU_CMP(&node->cpuset, &root->cpuset) == 0)) {
if (CPU_CMP(&node->cpuset, &root->cpuset) == 0) {
if (node->type == TOPO_TYPE_CACHE &&
cg_root->cg_level < node->subtype)
cg_root->cg_level = node->subtype;
if (node->type == TOPO_TYPE_NODE)
cg_root->cg_flags |= CG_FLAG_NODE;
node = topo_next_node(root, node);
continue;
}
if (node->type != TOPO_TYPE_GROUP &&
node->type != TOPO_TYPE_NODE &&
node->type != TOPO_TYPE_CACHE) {
node = topo_next_node(root, node);
continue;
}
@ -842,9 +898,9 @@ x86topo_add_sched_group(struct topo_node *root, struct cpu_group *cg_root)
i = 0;
while (node != NULL) {
if ((node->type != TOPO_TYPE_GROUP &&
node->type != TOPO_TYPE_NODE &&
node->type != TOPO_TYPE_CACHE) ||
(root->type != TOPO_TYPE_SYSTEM &&
CPU_CMP(&node->cpuset, &root->cpuset) == 0)) {
CPU_CMP(&node->cpuset, &root->cpuset) == 0) {
node = topo_next_node(root, node);
continue;
}