[patch v2 27/30] x86/cpu/topology: Rename smp_num_siblings

From: Thomas Gleixner
Date: Tue Jan 23 2024 - 08:28:53 EST


From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

It's really a non-intuitive name. Rename it to __max_threads_per_core which
is obvious.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>



---
arch/x86/include/asm/perf_event_p4.h | 4 ++--
arch/x86/include/asm/smp.h | 2 --
arch/x86/include/asm/topology.h | 1 +
arch/x86/kernel/cpu/common.c | 6 +++---
arch/x86/kernel/cpu/debugfs.c | 2 +-
arch/x86/kernel/cpu/mce/inject.c | 2 +-
arch/x86/kernel/cpu/topology.c | 6 +++---
arch/x86/kernel/process.c | 2 +-
arch/x86/kernel/smpboot.c | 2 +-
9 files changed, 13 insertions(+), 14 deletions(-)
---
--- a/arch/x86/include/asm/perf_event_p4.h
+++ b/arch/x86/include/asm/perf_event_p4.h
@@ -181,7 +181,7 @@ static inline u64 p4_clear_ht_bit(u64 co
static inline int p4_ht_active(void)
{
#ifdef CONFIG_SMP
- return smp_num_siblings > 1;
+ return __max_threads_per_core > 1;
#endif
return 0;
}
@@ -189,7 +189,7 @@ static inline int p4_ht_active(void)
static inline int p4_ht_thread(int cpu)
{
#ifdef CONFIG_SMP
- if (smp_num_siblings == 2)
+ if (__max_threads_per_core == 2)
return cpu != cpumask_first(this_cpu_cpumask_var_ptr(cpu_sibling_map));
#endif
return 0;
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -8,8 +8,6 @@
#include <asm/current.h>
#include <asm/thread_info.h>

-extern unsigned int smp_num_siblings;
-
DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_core_map);
DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_die_map);
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -145,6 +145,7 @@ extern const struct cpumask *cpu_cluster

extern unsigned int __max_dies_per_package;
extern unsigned int __max_logical_packages;
+extern unsigned int __max_threads_per_core;

static inline unsigned int topology_max_packages(void)
{
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -72,8 +72,8 @@
u32 elf_hwcap2 __read_mostly;

/* Number of siblings per CPU package */
-unsigned int smp_num_siblings __ro_after_init = 1;
-EXPORT_SYMBOL(smp_num_siblings);
+unsigned int __max_threads_per_core __ro_after_init = 1;
+EXPORT_SYMBOL(__max_threads_per_core);

unsigned int __max_dies_per_package __ro_after_init = 1;
EXPORT_SYMBOL(__max_dies_per_package);
@@ -2249,7 +2249,7 @@ void __init arch_cpu_finalize_init(void)
* identify_boot_cpu() initialized SMT support information, let the
* core code know.
*/
- cpu_smt_set_num_threads(smp_num_siblings, smp_num_siblings);
+ cpu_smt_set_num_threads(__max_threads_per_core, __max_threads_per_core);

if (!IS_ENABLED(CONFIG_SMP)) {
pr_info("CPU: ");
--- a/arch/x86/kernel/cpu/debugfs.c
+++ b/arch/x86/kernel/cpu/debugfs.c
@@ -30,7 +30,7 @@ static int cpu_debug_show(struct seq_fil
seq_printf(m, "amd_nodes_per_pkg: %u\n", topology_amd_nodes_per_pkg());
seq_printf(m, "max_cores: %u\n", c->x86_max_cores);
seq_printf(m, "max_dies_per_pkg: %u\n", __max_dies_per_package);
- seq_printf(m, "smp_num_siblings: %u\n", smp_num_siblings);
+ seq_printf(m, "max_threads_per_core:%u\n", __max_threads_per_core);
return 0;
}

--- a/arch/x86/kernel/cpu/mce/inject.c
+++ b/arch/x86/kernel/cpu/mce/inject.c
@@ -433,7 +433,7 @@ static u32 get_nbc_for_node(int node_id)
struct cpuinfo_x86 *c = &boot_cpu_data;
u32 cores_per_node;

- cores_per_node = (c->x86_max_cores * smp_num_siblings) / topology_amd_nodes_per_pkg();
+ cores_per_node = (c->x86_max_cores * __max_threads_per_core) / topology_amd_nodes_per_pkg();
return cores_per_node * node_id;
}

--- a/arch/x86/kernel/cpu/topology.c
+++ b/arch/x86/kernel/cpu/topology.c
@@ -76,7 +76,7 @@ bool arch_match_cpu_phys_id(int cpu, u64
#ifdef CONFIG_SMP
static void cpu_mark_primary_thread(unsigned int cpu, unsigned int apicid)
{
- if (!(apicid & (smp_num_siblings - 1)))
+ if (!(apicid & (__max_threads_per_core - 1)))
cpumask_set_cpu(cpu, &__cpu_primary_thread_mask);
}
#else
@@ -417,8 +417,8 @@ void __init topology_init_possible_cpus(

cnta = domain_weight(TOPO_CORE_DOMAIN);
cntb = domain_weight(TOPO_SMT_DOMAIN);
- smp_num_siblings = 1U << (get_count_order(cntb) - get_count_order(cnta));
- pr_info("Max. threads per core: %3u\n", smp_num_siblings);
+ __max_threads_per_core = 1U << (get_count_order(cntb) - get_count_order(cnta));
+ pr_info("Max. threads per core: %3u\n", __max_threads_per_core);

pr_info("Allowing %u present CPUs plus %u hotplug CPUs\n", assigned, disabled);
if (topo_info.nr_rejected_cpus)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -936,7 +936,7 @@ static __cpuidle void mwait_idle(void)
void select_idle_routine(const struct cpuinfo_x86 *c)
{
#ifdef CONFIG_SMP
- if (boot_option_idle_override == IDLE_POLL && smp_num_siblings > 1)
+ if (boot_option_idle_override == IDLE_POLL && __max_threads_per_core > 1)
pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n");
#endif
if (x86_idle_set() || boot_option_idle_override == IDLE_POLL)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -563,7 +563,7 @@ static void __init build_sched_topology(

void set_cpu_sibling_map(int cpu)
{
- bool has_smt = smp_num_siblings > 1;
+ bool has_smt = __max_threads_per_core > 1;
bool has_mp = has_smt || boot_cpu_data.x86_max_cores > 1;
struct cpuinfo_x86 *c = &cpu_data(cpu);
struct cpuinfo_x86 *o;