From 1184dc2ffe2c8fb9afb766d870850f2c3165ef25 Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Mon, 12 May 2008 21:21:12 +0200 Subject: x86: modify Kconfig to allow up to 4096 cpus * Increase the limit of NR_CPUS to 4096 and introduce a boolean called "MAXSMP" which when set (e.g. "allyesconfig"), will set NR_CPUS = 4096 and NODES_SHIFT = 9 (512). * Changed max setting for NODES_SHIFT from 15 to 9 to accurately reflect the real limit. Signed-off-by: Mike Travis Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/Kconfig | 37 ++++++++++++++++++++++++++++++++----- 1 file changed, 32 insertions(+), 5 deletions(-) (limited to 'arch/x86/Kconfig') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index bf07b6f50fa..2e325521e5e 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -561,20 +561,35 @@ config SWIOTLB config IOMMU_HELPER def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB) +config MAXSMP + bool "Configure Maximum number of SMP Processors and NUMA Nodes" + depends on X86_64 && SMP + default n + help + Configure maximum number of CPUS and NUMA Nodes for this architecture. + If unsure, say N. +if MAXSMP config NR_CPUS - int "Maximum number of CPUs (2-255)" - range 2 255 + int + default "4096" +endif + +if !MAXSMP +config NR_CPUS + int "Maximum number of CPUs (2-4096)" + range 2 4096 depends on SMP default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000 default "8" help This allows you to specify the maximum number of CPUs which this - kernel will support. The maximum supported value is 255 and the + kernel will support. The maximum supported value is 4096 and the minimum value which makes sense is 2. This is purely to save memory - each supported CPU adds approximately eight kilobytes to the kernel image. +endif config SCHED_SMT bool "SMT (Hyperthreading) scheduler support" @@ -965,13 +980,25 @@ config NUMA_EMU into virtual nodes when booted with "numa=fake=N", where N is the number of nodes. This is only useful for debugging. +if MAXSMP + +config NODES_SHIFT + int + default "9" +endif + +if !MAXSMP config NODES_SHIFT - int "Max num nodes shift(1-9)" - range 1 9 if X86_64 + int "Maximum NUMA Nodes (as a power of 2)" + range 1 9 if X86_64 default "6" if X86_64 default "4" if X86_NUMAQ default "3" depends on NEED_MULTIPLE_NODES + help + Specify the maximum number of NUMA Nodes available on the target + system. Increases memory reserved to accomodate various tables. +endif config HAVE_ARCH_BOOTMEM_NODE def_bool y -- cgit v1.2.3 From 23ca4bba3e20c6c3cb11c1bb0ab4770b724d39ac Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Mon, 12 May 2008 21:21:12 +0200 Subject: x86: cleanup early per cpu variables/accesses v4 * Introduce a new PER_CPU macro called "EARLY_PER_CPU". This is used by some per_cpu variables that are initialized and accessed before there are per_cpu areas allocated. ["Early" in respect to per_cpu variables is "earlier than the per_cpu areas have been setup".] This patchset adds these new macros: DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) EXPORT_EARLY_PER_CPU_SYMBOL(_name) DECLARE_EARLY_PER_CPU(_type, _name) early_per_cpu_ptr(_name) early_per_cpu_map(_name, _idx) early_per_cpu(_name, _cpu) The DEFINE macro defines the per_cpu variable as well as the early map and pointer. It also initializes the per_cpu variable and map elements to "_initvalue". The early_* macros provide access to the initial map (usually setup during system init) and the early pointer. This pointer is initialized to point to the early map but is then NULL'ed when the actual per_cpu areas are setup. After that the per_cpu variable is the correct access to the variable. The early_per_cpu() macro is not very efficient but does show how to access the variable if you have a function that can be called both "early" and "late". It tests the early ptr to be NULL, and if not then it's still valid. Otherwise, the per_cpu variable is used instead: #define early_per_cpu(_name, _cpu) \ (early_per_cpu_ptr(_name) ? \ early_per_cpu_ptr(_name)[_cpu] : \ per_cpu(_name, _cpu)) A better method is to actually check the pointer manually. In the case below, numa_set_node can be called both "early" and "late": void __cpuinit numa_set_node(int cpu, int node) { int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map); if (cpu_to_node_map) cpu_to_node_map[cpu] = node; else per_cpu(x86_cpu_to_node_map, cpu) = node; } * Add a flag "arch_provides_topology_pointers" that indicates pointers to topology cpumask_t maps are available. Otherwise, use the function returning the cpumask_t value. This is useful if cpumask_t set size is very large to avoid copying data on to/off of the stack. * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while the non-debug case has been optimized a bit. * Remove an unreferenced compiler warning in drivers/base/topology.c * Clean up #ifdef in setup.c For inclusion into sched-devel/latest tree. Based on: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git + sched-devel/latest .../mingo/linux-2.6-sched-devel.git Signed-off-by: Mike Travis Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/x86/Kconfig') diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 2e325521e5e..4469a0db1ae 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -121,7 +121,7 @@ config ARCH_HAS_CACHE_LINE_SIZE def_bool y config HAVE_SETUP_PER_CPU_AREA - def_bool X86_64 || (X86_SMP && !X86_VOYAGER) + def_bool X86_64_SMP || (X86_SMP && !X86_VOYAGER) config HAVE_CPUMASK_OF_CPU_MAP def_bool X86_64_SMP -- cgit v1.2.3