Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'x86-urgent-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
"Fix a CPU topology code regression that caused the mishandling of
certain boot command line options, and re-enable CONFIG_PTDUMP on i386
that was mistakenly turned off in the Kconfig"
* tag 'x86-urgent-2025-09-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/topology: Implement topology_is_core_online() to address SMT regression
x86/Kconfig: Reenable PTDUMP on i386
+24
-1
+1
-1
arch/x86/Kconfig
+1
-1
arch/x86/Kconfig
···
26
26
depends on 64BIT
27
27
# Options that are inherently 64-bit kernel only:
28
28
select ARCH_HAS_GIGANTIC_PAGE
29
-
select ARCH_HAS_PTDUMP
30
29
select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
31
30
select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
32
31
select ARCH_SUPPORTS_PER_VMA_LOCK
···
98
99
select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
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100
select ARCH_HAS_PMEM_API if X86_64
100
101
select ARCH_HAS_PREEMPT_LAZY
102
+
select ARCH_HAS_PTDUMP
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103
select ARCH_HAS_PTE_SPECIAL
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104
select ARCH_HAS_HW_PTE_YOUNG
103
105
select ARCH_HAS_NONLEAF_PMD_YOUNG if PGTABLE_LEVELS > 2
+10
arch/x86/include/asm/topology.h
+10
arch/x86/include/asm/topology.h
···
231
231
}
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232
#define topology_is_primary_thread topology_is_primary_thread
233
233
234
+
int topology_get_primary_thread(unsigned int cpu);
235
+
236
+
static inline bool topology_is_core_online(unsigned int cpu)
237
+
{
238
+
int pcpu = topology_get_primary_thread(cpu);
239
+
240
+
return pcpu >= 0 ? cpu_online(pcpu) : false;
241
+
}
242
+
#define topology_is_core_online topology_is_core_online
243
+
234
244
#else /* CONFIG_SMP */
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245
static inline int topology_phys_to_logical_pkg(unsigned int pkg) { return 0; }
236
246
static inline int topology_max_smt_threads(void) { return 1; }
+13
arch/x86/kernel/cpu/topology.c
+13
arch/x86/kernel/cpu/topology.c
···
372
372
return topo_unit_count(lvlid, at_level, apic_maps[which_units].map);
373
373
}
374
374
375
+
#ifdef CONFIG_SMP
376
+
int topology_get_primary_thread(unsigned int cpu)
377
+
{
378
+
u32 apic_id = cpuid_to_apicid[cpu];
379
+
380
+
/*
381
+
* Get the core domain level APIC id, which is the primary thread
382
+
* and return the CPU number assigned to it.
383
+
*/
384
+
return topo_lookup_cpuid(topo_apicid(apic_id, TOPO_CORE_DOMAIN));
385
+
}
386
+
#endif
387
+
375
388
#ifdef CONFIG_ACPI_HOTPLUG_CPU
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389
/**
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* topology_hotplug_apic - Handle a physical hotplugged APIC after boot