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| author |  Thomas Gleixner <tglx@linutronix.de>
| 2024-02-13 22:06:03 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de>
| 2024-02-15 22:07:44 +0100 |
| commit | 090610ba704a66d7a58919be3bad195f24499ecb (patch) | |
| tree | 240519e75fbb7f210c5b9b0ae9059ee08d443812 /arch/x86/include/asm/smp.h | |
| parent | x86/cpu/topology: Let XEN/PV use topology from CPUID/MADT (diff) | |
| download | linux-090610ba704a66d7a58919be3bad195f24499ecb.tar.gz linux-090610ba704a66d7a58919be3bad195f24499ecb.tar.bz2 linux-090610ba704a66d7a58919be3bad195f24499ecb.zip | |
x86/cpu/topology: Use topology bitmaps for sizing
Now that all possible APIC IDs are tracked in the topology bitmaps, its
trivial to retrieve the real information from there.
This gets rid of the guesstimates for the maximal packages and dies per
package as the actual numbers can be determined before a single AP has been
brought up.
The number of SMT threads can now be determined correctly from the bitmaps
in all situations. Up to now a system which has SMT disabled in the BIOS
will still claim that it is SMT capable, because the lowest APIC ID bit is
reserved for that and CPUID leaf 0xb/0x1f still enumerates the SMT domain
accordingly. By calculating the bitmap weights of the SMT and the CORE
domain and setting them into relation the SMT disabled in BIOS situation
reports correctly that the system is not SMT capable.
It also handles the situation correctly when a hybrid systems boot CPU does
not have SMT as it takes the SMT capability of the APs fully into account.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.681709880@linutronix.de
Diffstat (limited to 'arch/x86/include/asm/smp.h')
| -rw-r--r-- | arch/x86/include/asm/smp.h | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index f1510d6f4e84..5318470cea02 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -8,7 +8,7 @@ #include <asm/current.h> #include <asm/thread_info.h> -extern int smp_num_siblings; +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); @@ -109,7 +109,6 @@ void cpu_disable_common(void); void native_smp_prepare_boot_cpu(void); void smp_prepare_cpus_common(void); void native_smp_prepare_cpus(unsigned int max_cpus); -void calculate_max_logical_packages(void); void native_smp_cpus_done(unsigned int max_cpus); int common_cpu_up(unsigned int cpunum, struct task_struct *tidle); int native_kick_ap(unsigned int cpu, struct task_struct *tidle); |