Broadcast now depends on the fact that all present CPUs have been booted once so handling broadcast IPIs is not doing any harm. In case that a CPU is offline, it does not react to regular IPIs and the NMI handler returns early.
Signed-off-by: Thomas Gleixner <[email protected]> --- arch/x86/kernel/apic/ipi.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) --- a/arch/x86/kernel/apic/ipi.c +++ b/arch/x86/kernel/apic/ipi.c @@ -8,13 +8,7 @@ DEFINE_STATIC_KEY_FALSE(apic_use_ipi_shorthand); #ifdef CONFIG_SMP -#ifdef CONFIG_HOTPLUG_CPU -#define DEFAULT_SEND_IPI (1) -#else -#define DEFAULT_SEND_IPI (0) -#endif - -static int apic_ipi_shorthand_off __ro_after_init = DEFAULT_SEND_IPI; +static int apic_ipi_shorthand_off __ro_after_init; static __init int apic_ipi_shorthand(char *str) { @@ -250,7 +244,7 @@ void default_send_IPI_allbutself(int vec if (num_online_cpus() < 2) return; - if (apic_ipi_shorthand_off || vector == NMI_VECTOR) { + if (static_branch_likely(&apic_use_ipi_shorthand)) { apic->send_IPI_mask_allbutself(cpu_online_mask, vector); } else { __default_send_IPI_shortcut(APIC_DEST_ALLBUT, vector); @@ -259,7 +253,7 @@ void default_send_IPI_allbutself(int vec void default_send_IPI_all(int vector) { - if (apic_ipi_shorthand_off || vector == NMI_VECTOR) { + if (static_branch_likely(&apic_use_ipi_shorthand)) { apic->send_IPI_mask(cpu_online_mask, vector); } else { __default_send_IPI_shortcut(APIC_DEST_ALLINC, vector);
