Messages in this thread | | | Date | Sun, 22 Jul 2007 15:54:21 -0700 | From | "Yinghai Lu" <> | Subject | Re: [PATCH 3/3] x86_64: offset apicid_to_node before use it before init_cpu_to_node |
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On 7/22/07, Andi Kleen <ak@suse.de> wrote: > On Sunday 22 July 2007 02:49:41 Yinghai Lu wrote: > > [PATCH 3/3] x86_64: offset apicid_to_node before use it before init_cpu_to_node > > > > When acpi=off or there is no SRAT defined, apicid_to_node is got from K8 > > Northbridge PCI configuration space in k8_scan_nodes() in > > arch/x86_64/mm/k8toplogy.c. > > The problem is that it assumes bsp apic id is 0 at that point. > > For four socket system with Quad core cpus installed, all cpus apic id > > is offset by 4, and bsp apic id is 4. > > For eight socket system with dual core cpus installed, all cpus apic id > > is offset by 2, and bsp apic id is 2. > > We need offset apicid_to_node array according to boot_cpu_id.--- bsp apic id. > > before we use apicid_to_node array. > > boot_cpu_id is only valid init_apic_mappings. > > <rant> > This thing is getting more and more messy. If it gets any more complicated > I promise I'll rip out the non ACPI support for quad core NUMA completely > and let it require ACPI. Even the people who have a religious problem > with ACPI will need to eventually get over it and LinuxBIOS just has > to create proper tables, not pile hacks over hacks. It probably was a mistake in > the first place to add it. > </rant> you will need to force every BIOS to have correct SRAT table. > > I don't think you can mess with apicid_to_node[] unconditionally here. > e.g. for the ACPI case or for the Intel NUMA case you'll just break everything. > > What you should do is split init_apic_mappings() up and do a early > call that just checks if the CPU has an APIC and maps it using the > fixmap and reads boot_cpu_id. Then you can use that information > in k8topology.c to create correct tables.
sounds good, i try to split one init_lapic_mappings from init_apic_mappings
Thanks
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