Messages in this thread Patch in this message |  | | From | Fernando Fernandez Mancera <> | | Subject | [PATCH RESEND] x86/cpu/topology: remove limit of CPUs due to noapic on x86_64 | | Date | Sun, 24 Nov 2024 18:45:07 +0100 |
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On x86_64 the command line parameter "noapic" should not limit the number of possible CPUs, as it only limits the use of IRQ sharing or device IRQ remapping. Only on x86_32 the command line parameter "nolapic" limits the number of possible CPUs to one. This restores the behavior previous to the rework of possible CPU management.
Fixes: 7c0edad3643f ("x86/cpu/topology: Rework possible CPU management") Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net> --- RESEND: original patch https://lkml.org/lkml/2024/9/7/160 --- arch/x86/kernel/cpu/topology.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kernel/cpu/topology.c b/arch/x86/kernel/cpu/topology.c index 621a151ccf7d..5f10a010e35a 100644 --- a/arch/x86/kernel/cpu/topology.c +++ b/arch/x86/kernel/cpu/topology.c @@ -428,10 +428,16 @@ void __init topology_apply_cmdline_limits_early(void) { unsigned int possible = nr_cpu_ids; - /* 'maxcpus=0' 'nosmp' 'nolapic' 'disableapic' 'noapic' */ - if (!setup_max_cpus || ioapic_is_disabled || apic_is_disabled) + /* 'maxcpus=0' 'nosmp' */ + if (!setup_max_cpus) possible = 1; +#if defined(CONFIG_X86_32) + /* 'nolapic' 'disableapic' 'noapic' */ + if (apic_is_disabled || ioapic_is_disabled) + possible = 1; +#endif + /* 'possible_cpus=N' */ possible = min_t(unsigned int, max_possible_cpus, possible); @@ -443,8 +449,14 @@ void __init topology_apply_cmdline_limits_early(void) static __init bool restrict_to_up(void) { - if (!smp_found_config || ioapic_is_disabled) + if (!smp_found_config) return true; + +#if defined(CONFIG_X86_32) + if (ioapic_is_disabled) + return true; +#endif + /* * XEN PV is special as it does not advertise the local APIC * properly, but provides a fake topology for it so that the -- 2.46.2
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