Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'x86-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cpu fix from Thomas Gleixner:
"A single fix for x86:
- Prevent a bogus setting for the number of HT siblings, which is
caused by the CPUID evaluation trainwreck of X86. That recomputes
the value for each CPU, so the last CPU "wins". That can cause
completely bogus sibling values"
* tag 'x86-urgent-2023-05-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/topology: Fix erroneous smp_num_siblings on Intel Hybrid platforms
+3
-2
+3
-2
arch/x86/kernel/cpu/topology.c
+3
-2
arch/x86/kernel/cpu/topology.c
···
79
79
* initial apic id, which also represents 32-bit extended x2apic id.
80
80
*/
81
81
c->initial_apicid = edx;
82
-
smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
82
+
smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx));
83
83
#endif
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return 0;
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85
}
···
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109
*/
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110
cpuid_count(leaf, SMT_LEVEL, &eax, &ebx, &ecx, &edx);
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111
c->initial_apicid = edx;
112
-
core_level_siblings = smp_num_siblings = LEVEL_MAX_SIBLINGS(ebx);
112
+
core_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
113
+
smp_num_siblings = max_t(int, smp_num_siblings, LEVEL_MAX_SIBLINGS(ebx));
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114
core_plus_mask_width = ht_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);
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115
die_level_siblings = LEVEL_MAX_SIBLINGS(ebx);
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pkg_mask_width = die_plus_mask_width = BITS_SHIFT_NEXT_LEVEL(eax);