Author: cem Date: Thu Aug 17 16:54:37 2017 New Revision: 322621 URL: https://svnweb.freebsd.org/changeset/base/322621
Log: Discover CPU topology on multi-die AMD Zen systems The Nodes per Processor topology information determines how many bits of the APIC ID represent the Node (Zeppelin die, on Zen systems) ID. Documented in Ryzen and Epyc Processor Programming Reference (PPR). Correct topology information enables the scheduler to make better decisions on this hardware. Reviewed by: kib@ Tested by: jeff@ (earlier version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D11801 Modified: head/sys/x86/x86/mp_x86.c Modified: head/sys/x86/x86/mp_x86.c ============================================================================== --- head/sys/x86/x86/mp_x86.c Thu Aug 17 14:40:48 2017 (r322620) +++ head/sys/x86/x86/mp_x86.c Thu Aug 17 16:54:37 2017 (r322621) @@ -155,6 +155,7 @@ SYSCTL_INT(_machdep, OID_AUTO, hyperthreading_allowed, static struct topo_node topo_root; static int pkg_id_shift; +static int node_id_shift; static int core_id_shift; static int disabled_cpus; @@ -274,6 +275,15 @@ topo_probe_amd(void) cpuid_count(0x8000001e, 0, p); share_count = ((p[1] >> 8) & 0xff) + 1; core_id_shift = mask_width(share_count); + + /* + * For Zen (17h), gather Nodes per Processor. Each node is a + * Zeppelin die; TR and EPYC CPUs will have multiple dies per + * package. Communication latency between dies is higher than + * within them. + */ + nodes_per_socket = ((p[2] >> 8) & 0x7) + 1; + node_id_shift = pkg_id_shift - mask_width(nodes_per_socket); } if ((amd_feature2 & AMDID2_TOPOLOGY) != 0) { @@ -483,7 +493,7 @@ topo_probe(void) int type; int subtype; int id_shift; - } topo_layers[MAX_CACHE_LEVELS + 3]; + } topo_layers[MAX_CACHE_LEVELS + 4]; struct topo_node *parent; struct topo_node *node; int layer; @@ -515,6 +525,15 @@ topo_probe(void) printf("Package ID shift: %u\n", topo_layers[nlayers].id_shift); nlayers++; + if (pkg_id_shift > node_id_shift && node_id_shift != 0) { + topo_layers[nlayers].type = TOPO_TYPE_GROUP; + topo_layers[nlayers].id_shift = node_id_shift; + if (bootverbose) + printf("Node ID shift: %u\n", + topo_layers[nlayers].id_shift); + nlayers++; + } + /* * Consider all caches to be within a package/chip * and "in front" of all sub-components like @@ -522,6 +541,9 @@ topo_probe(void) */ for (i = MAX_CACHE_LEVELS - 1; i >= 0; --i) { if (caches[i].present) { + if (node_id_shift != 0) + KASSERT(caches[i].id_shift <= node_id_shift, + ("bug in APIC topology discovery")); KASSERT(caches[i].id_shift <= pkg_id_shift, ("bug in APIC topology discovery")); KASSERT(caches[i].id_shift >= core_id_shift, @@ -720,7 +742,8 @@ x86topo_add_sched_group(struct topo_node *root, struct int ncores; int i; - KASSERT(root->type == TOPO_TYPE_SYSTEM || root->type == TOPO_TYPE_CACHE, + KASSERT(root->type == TOPO_TYPE_SYSTEM || root->type == TOPO_TYPE_CACHE || + 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; @@ -760,7 +783,8 @@ x86topo_add_sched_group(struct topo_node *root, struct nchildren = 0; node = root; while (node != NULL) { - if (node->type != TOPO_TYPE_CACHE || + if ((node->type != TOPO_TYPE_GROUP && + node->type != TOPO_TYPE_CACHE) || (root->type != TOPO_TYPE_SYSTEM && CPU_CMP(&node->cpuset, &root->cpuset) == 0)) { node = topo_next_node(root, node); @@ -780,7 +804,8 @@ x86topo_add_sched_group(struct topo_node *root, struct node = root; i = 0; while (node != NULL) { - if (node->type != TOPO_TYPE_CACHE || + if ((node->type != TOPO_TYPE_GROUP && + node->type != TOPO_TYPE_CACHE) || (root->type != TOPO_TYPE_SYSTEM && CPU_CMP(&node->cpuset, &root->cpuset) == 0)) { node = topo_next_node(root, node); _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
