Commit-ID: 418f727639cfc8f03068aae09f473c493c759b9b Gitweb: http://git.kernel.org/tip/418f727639cfc8f03068aae09f473c493c759b9b Author: Suresh Siddha <suresh.b.siddha@xxxxxxxxx> AuthorDate: Tue, 9 Feb 2010 09:18:35 -0800 Committer: H. Peter Anvin <hpa@xxxxxxxxx> CommitDate: Tue, 9 Feb 2010 09:29:17 -0800 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, 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. Reported-by: Shaohui Zheng <shaohui.zheng@xxxxxxxxx> Acked-by: Shaohui Zheng <shaohui.zheng@xxxxxxxxx> Cc: Yinghai Lu <yinghai@xxxxxxxxxx> LKML-Reference: <20100118201256.672679042@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx> Cc: <stable@xxxxxxxxxx> --- arch/x86/kernel/apic/apic.c | 2 +- arch/x86/kernel/apic/probe_64.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 3987e44..fc1d579 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1892,7 +1892,7 @@ void __cpuinit generic_processor_info(int apicid, int version) max_physical_apicid = apicid; #ifdef CONFIG_X86_32 - if (num_processors > 8) { + if (num_possible_cpus() > 8) { switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_INTEL: if (!APIC_XAPIC(version)) { diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c index 450fe20..83e9be4 100644 --- a/arch/x86/kernel/apic/probe_64.c +++ b/arch/x86/kernel/apic/probe_64.c @@ -67,7 +67,7 @@ void __init default_setup_apic_routing(void) } #endif - if (apic == &apic_flat && num_processors > 8) + if (apic == &apic_flat && num_possible_cpus() > 8) apic = &apic_physflat; printk(KERN_INFO "Setting APIC routing to %s\n", apic->name); -- 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