diff options
| author | Suresh Siddha <suresh.b.siddha@intel.com> | 2010-01-18 12:10:49 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-01-18 14:15:28 -0800 |
| commit | bb668da6d6f2bec8a63838c098d9515eccb22cc4 (patch) | |
| tree | d41b25f7f9a8dcfcfeea13be8035799f3e154216 /arch/x86/kernel/apic/probe_64.c | |
| parent | dfea91d5a7c795fd6f4e1a97489a98e4e767463e (diff) | |
x86, apic: use logical flat for systems with <= 8 logical cpus
We can use logical flat mode if there are <= 8 logical cpu's
(irrespective of physical apic id values). This will enable simplified
and efficient IPI and device interrupt routing on such platforms.
This has been tested to work on both Intel and AMD platforms.
Exceptions like IBM summit platform which can't use logical flat mode
are addressed by using OEM platform checks.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Chris McDermott <lcm@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel/apic/probe_64.c')
| -rw-r--r-- | arch/x86/kernel/apic/probe_64.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c index 65edc180fc8..450fe2064a1 100644 --- a/arch/x86/kernel/apic/probe_64.c +++ b/arch/x86/kernel/apic/probe_64.c @@ -64,15 +64,13 @@ void __init default_setup_apic_routing(void) apic = &apic_x2apic_phys; else apic = &apic_x2apic_cluster; - printk(KERN_INFO "Setting APIC routing to %s\n", apic->name); } #endif - if (apic == &apic_flat) { - if (max_physical_apicid >= 8) + if (apic == &apic_flat && num_processors > 8) apic = &apic_physflat; - printk(KERN_INFO "Setting APIC routing to %s\n", apic->name); - } + + printk(KERN_INFO "Setting APIC routing to %s\n", apic->name); if (is_vsmp_box()) { /* need to update phys_pkg_id */ |