From 05b3cbd8bb98736387df8a2e1efe311b1fb4d2ad Mon Sep 17 00:00:00 2001 From: Ravikiran Thirumalai Date: Wed, 11 Jan 2006 22:45:36 +0100 Subject: [PATCH] [PATCH] x86_64: Early initialization of cpu_to_node Patch enables early intialization of cpu_to_node. apicid_to_node is built by reading the SRAT table, from acpi_numa_init with ACPI_NUMA and k8_scan_nodes with K8_NUMA. x86_cpu_to_apicid is built by parsing the ACPI MADT table, from acpi_boot_init. We combine these two tables and setup cpu_to_node. Early intialization helps the static per_cpu_areas in getting pages from correct node. Change since last release: Do not initialize early init_cpu_to_node for faking node cases. Patch tested on TYAN dual core 4P board with K8 only, ACPI_NUMA. Tested on EM64T NUMA. Also tested with numa=off, numa=fake, and running a kernel compiled with NUMA on a regular EM64 2 way SMP. Signed-off-by: Alok N Kataria Signed-off-by: Ravikiran Thirumalai Signed-off-by: Shai Fultheim Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/x86_64/kernel/setup.c | 2 ++ arch/x86_64/mm/numa.c | 25 +++++++++++++++++++++++++ include/asm-x86_64/numa.h | 5 +++++ 3 files changed, 32 insertions(+) diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c index 46bf556efc3..173bdc55113 100644 --- a/arch/x86_64/kernel/setup.c +++ b/arch/x86_64/kernel/setup.c @@ -713,6 +713,8 @@ void __init setup_arch(char **cmdline_p) acpi_boot_init(); #endif + init_cpu_to_node(); + #ifdef CONFIG_X86_LOCAL_APIC /* * get boot-time SMP configuration: diff --git a/arch/x86_64/mm/numa.c b/arch/x86_64/mm/numa.c index 42ec1f4f491..876e3437441 100644 --- a/arch/x86_64/mm/numa.c +++ b/arch/x86_64/mm/numa.c @@ -330,6 +330,31 @@ __init int numa_setup(char *opt) return 1; } +/* + * Setup early cpu_to_node. + * + * Populate cpu_to_node[] only if x86_cpu_to_apicid[], + * and apicid_to_node[] tables have valid entries for a CPU. + * This means we skip cpu_to_node[] initialisation for NUMA + * emulation and faking node case (when running a kernel compiled + * for NUMA on a non NUMA box), which is OK as cpu_to_node[] + * is already initialized in a round robin manner at numa_init_array, + * prior to this call, and this initialization is good enough + * for the fake NUMA cases. + */ +void __init init_cpu_to_node(void) +{ + int i; + for (i = 0; i < NR_CPUS; i++) { + u8 apicid = x86_cpu_to_apicid[i]; + if (apicid == BAD_APICID) + continue; + if (apicid_to_node[apicid] == NUMA_NO_NODE) + continue; + cpu_to_node[i] = apicid_to_node[apicid]; + } +} + EXPORT_SYMBOL(cpu_to_node); EXPORT_SYMBOL(node_to_cpumask); EXPORT_SYMBOL(memnode_shift); diff --git a/include/asm-x86_64/numa.h b/include/asm-x86_64/numa.h index d51e56fdc3d..34e434ce326 100644 --- a/include/asm-x86_64/numa.h +++ b/include/asm-x86_64/numa.h @@ -20,6 +20,11 @@ extern int numa_off; extern void numa_set_node(int cpu, int node); extern unsigned char apicid_to_node[256]; +#ifdef CONFIG_NUMA +extern void __init init_cpu_to_node(void); +#else +#define init_cpu_to_node() do {} while (0) +#endif #define NUMA_NO_NODE 0xff -- 2.11.4.GIT