On 02/09/2010 06:26 PM, Yinghai Lu wrote: > On 02/09/2010 06:01 PM, Suresh Siddha wrote: >> On Tue, 2010-02-09 at 10:47 -0800, Yinghai Lu wrote: >>>> #ifdef CONFIG_X86_32 >>>> - if (num_processors > 8) { >>>> + if (num_possible_cpus() > 8) { >>> >>> for 32bit you can not use this function yet. >>> that only can be used after prefill_possible_map() >> >> Yinghai, Agreed. How about the appended patch? I tested and it works. >> Peter wants a small quick fix for this issue (to resolve the boot issue >> reported in the virtualization guest context) so that we can queue it >> for .33 and .32 kernels (as some distributions will be based on these >> kernels). >> >> Can you please Ack if it is ok? >> >> thanks, >> suresh >> --- >> >> From: Suresh Siddha <suresh.b.siddha@xxxxxxxxx> >> Subject: x86, apic: Don't use logical-flat mode when CPU hotplug may exceed 8 CPUs >> >> We need to fall back from logical-flat APIC mode to physical-flat mode >> when we have more than 8 CPUs. However, in the presence of CPU >> hotplug(with bios listing not enabled but possible cpus as disabled cpus in >> MADT), we have to consider the number of possible CPUs rather than >> the number of current CPUs; otherwise we may cross the 8-CPU boundary >> when CPUs are added later. >> >> 32bit apic code can use more cleanups (like the removal of vendor checks in >> 32bit default_setup_apic_routing()) and more unifications with 64bit code. >> Yinghai has some patches in works already. This patch addresses the boot issue >> that is reported in the virtualization guest context. >> >> Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx> >> Acked-by: Shaohui Zheng <shaohui.zheng@xxxxxxxxx> >> Cc: <stable@xxxxxxxxxx> >> --- >> >> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c >> index 036d28a..0acbcdf 100644 >> --- a/arch/x86/kernel/acpi/boot.c >> +++ b/arch/x86/kernel/acpi/boot.c >> @@ -1185,9 +1185,6 @@ static void __init acpi_process_madt(void) >> if (!error) { >> acpi_lapic = 1; >> >> -#ifdef CONFIG_X86_BIGSMP >> - generic_bigsmp_probe(); >> -#endif >> /* >> * Parse MADT IO-APIC entries >> */ >> @@ -1197,8 +1194,6 @@ static void __init acpi_process_madt(void) >> acpi_ioapic = 1; >> >> smp_found_config = 1; >> - if (apic->setup_apic_routing) >> - apic->setup_apic_routing(); >> } >> } >> if (error == -EINVAL) { >> diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c >> index a85f216..6e29b2a 100644 >> --- a/arch/x86/kernel/apic/apic.c >> +++ b/arch/x86/kernel/apic/apic.c >> @@ -1641,9 +1641,7 @@ int __init APIC_init_uniprocessor(void) >> #endif >> >> enable_IR_x2apic(); >> -#ifdef CONFIG_X86_64 >> default_setup_apic_routing(); >> -#endif >> >> verify_local_APIC(); >> connect_bsp_APIC(); >> @@ -1891,21 +1889,6 @@ void __cpuinit generic_processor_info(int apicid, int version) >> if (apicid > max_physical_apicid) >> max_physical_apicid = apicid; >> >> -#ifdef CONFIG_X86_32 >> - if (num_processors > 8) { >> - switch (boot_cpu_data.x86_vendor) { >> - case X86_VENDOR_INTEL: >> - if (!APIC_XAPIC(version)) { >> - def_to_bigsmp = 0; >> - break; >> - } >> - /* If P4 and above fall through */ >> - case X86_VENDOR_AMD: >> - def_to_bigsmp = 1; >> - } >> - } >> -#endif >> - >> #if defined(CONFIG_SMP) || defined(CONFIG_X86_64) >> early_per_cpu(x86_cpu_to_apicid, cpu) = apicid; >> early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid; >> diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c >> index 1a6559f..88e78ae 100644 >> --- a/arch/x86/kernel/apic/probe_32.c >> +++ b/arch/x86/kernel/apic/probe_32.c >> @@ -54,6 +54,31 @@ late_initcall(print_ipi_mode); >> >> void default_setup_apic_routing(void) >> { >> + int version = apic_version[boot_cpu_physical_apicid]; >> + >> + if (num_possible_cpus() > 8) { >> + switch (boot_cpu_data.x86_vendor) { >> + case X86_VENDOR_INTEL: >> + if (!APIC_XAPIC(version)) { >> + def_to_bigsmp = 0; >> + break; >> + } >> + /* If P4 and above fall through */ >> + case X86_VENDOR_AMD: >> + def_to_bigsmp = 1; >> + } >> + } >> + >> +#ifdef CONFIG_X86_BIGSMP >> + generic_bigsmp_probe(); >> +#endif >> + >> + if (apic->setup_apic_routing) >> + apic->setup_apic_routing(); > > the main difference between this patch and > http://patchwork.kernel.org/patch/74525/ > > is moving apic->setup_apic_routing calling. > > wonder if it will affect subarch other than logical flat and physical flat. other subarch setup_apic_routing is just pr_info... so your patch should be ok. YH -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html