Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758933Ab0APDKR (ORCPT ); Fri, 15 Jan 2010 22:10:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758876Ab0APDKG (ORCPT ); Fri, 15 Jan 2010 22:10:06 -0500 Received: from sca-es-mail-2.Sun.COM ([192.18.43.133]:33978 "EHLO sca-es-mail-2.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758859Ab0APDIY (ORCPT ); Fri, 15 Jan 2010 22:08:24 -0500 MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: TEXT/PLAIN Date: Fri, 15 Jan 2010 19:07:03 -0800 From: Yinghai Lu Subject: [PATCH 32/37] x86, apic: Use logical flat on intel with <= 8 logical cpus In-reply-to: <1263611228-6751-1-git-send-email-yinghai@kernel.org> To: Ingo Molnar , Thomas Gleixner , "H. Peter Anvin" , Andrew Morton , Jesse Barnes , Christoph Lameter Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Suresh Siddha , "yinghai@kernel.org" , Ingo Molnar Message-id: <1263611228-6751-33-git-send-email-yinghai@kernel.org> X-Mailer: git-send-email 1.6.4.2 References: <1263611228-6751-1-git-send-email-yinghai@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Suresh Siddha On Intel platforms, 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. Fix the relevant comments while we are at it. We can clean up default_setup_apic_routing() by using apic->probe() but that is a different item. Signed-off-by: Suresh Siddha Cc: "yinghai@kernel.org" LKML-Reference: <1253327399.3948.747.camel@sbs-t61.sc.intel.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/apic.c | 26 ++++++++------------------ arch/x86/kernel/apic/probe_64.c | 15 +++++++++++---- 2 files changed, 19 insertions(+), 22 deletions(-) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index e80f291..aa57c07 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -62,7 +62,7 @@ unsigned int boot_cpu_physical_apicid = -1U; /* * The highest APIC ID seen during enumeration. * - * This determines the messaging protocol we can use: if all APIC IDs + * On AMD, this determines the messaging protocol we can use: if all APIC IDs * are in the 0 ... 7 range, then we can use logical addressing which * has some performance advantages (better broadcasting). * @@ -1898,24 +1898,14 @@ void __cpuinit generic_processor_info(int apicid, int version) max_physical_apicid = apicid; #ifdef CONFIG_X86_32 - /* - * Would be preferable to switch to bigsmp when CONFIG_HOTPLUG_CPU=y - * but we need to work other dependencies like SMP_SUSPEND etc - * before this can be done without some confusion. - * if (CPU_HOTPLUG_ENABLED || num_processors > 8) - * - Ashok Raj - */ - if (max_physical_apicid >= 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: + switch (boot_cpu_data.x86_vendor) { + case X86_VENDOR_INTEL: + if (num_processors > 8) + def_to_bigsmp = 1; + break; + case X86_VENDOR_AMD: + if (max_physical_apicid >= 8) def_to_bigsmp = 1; - } } #endif diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c index 65edc18..c4cbd30 100644 --- a/arch/x86/kernel/apic/probe_64.c +++ b/arch/x86/kernel/apic/probe_64.c @@ -64,16 +64,23 @@ 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) - apic = &apic_physflat; - printk(KERN_INFO "Setting APIC routing to %s\n", apic->name); + switch (boot_cpu_data.x86_vendor) { + case X86_VENDOR_INTEL: + if (num_processors > 8) + apic = &apic_physflat; + break; + case X86_VENDOR_AMD: + if (max_physical_apicid >= 8) + apic = &apic_physflat; + } } + printk(KERN_INFO "Setting APIC routing to %s\n", apic->name); + if (is_vsmp_box()) { /* need to update phys_pkg_id */ apic->phys_pkg_id = apicid_phys_pkg_id; -- 1.6.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/