The attached patch significantly shrinks boot memory allocation on ia64. It does this by not allocating per_cpu areas for cpus that can never exist. In the case where acpi does not have any numa node description of the cpus, I defaulted to assigning the first 4 to node 0. For the !CONFIG_ACPI I used for_each_possible_cpu(). Signed-off-by: Robin Holt <holt@xxxxxxx> --- I tested all the different config options. allyesconfig fails with or without this patch so that was the one exception. Otherwise, allnoconfig, allmodconfig, deconfig, and configs/* all compiled. Additionally, I booted the sn2- and defconfig both on altix and the defconfig on a zx2000 with 2 cpus. I would like it if somebody with access to a simulator could build and boot this. That is a different code path which I have no means of checking. Version 3: I reworked this patch to use a cpumask to track the cpus we have seen. It still initializes the .nid to NUMA_NO_NODE (-1). The introcution of a bitmask makes the scans much cleaner. This patch could be using the cpu_possible_map instead of our own. I was reluctant to do that, but there is nothing that prevents it. Does anybody have an opinion? Version 2 fixed a port bug. It also introduces NUMA_NO_NODE for ia64. This is a direct copy from x86. One comment I have received is the hard-coded 4 described above should probably be 8 or 16 to handle larger non-NUMA machines. I originally set it to 4 because my recollection was that, at most, you could have four processors per FSB, but maybe that is just an SGI limitation. How should this be set? Should I be using a PAL call? processor model? Limit by current FSB spec and adjust as new processors come along? Using a patched SuSE SLES10 kernel with both the mca patch that Jack/Russ submitted a couple days ago and the attached. On a 2 cpu, 6GB system, NR_CPUS=4096: Before the patch: Memory: 5687728k/6234784k available (5777k code, 579632k reserved, 10450k data, 672k init) After both patches: Memory: 6211984k/6235040k available (5552k code, 55376k reserved, 10418k data, 656k init) 90% savings on reserved. On a 1 cpu, 1GB system, NR_CPUS=4096 before 572,464K, after 37,456k for a 93% savings. Index: per_cpu/arch/ia64/kernel/setup.c =================================================================== --- per_cpu.orig/arch/ia64/kernel/setup.c 2008-02-08 15:05:45.564741552 -0600 +++ per_cpu/arch/ia64/kernel/setup.c 2008-02-08 16:38:18.763202424 -0600 @@ -45,6 +45,7 @@ #include <linux/cpufreq.h> #include <linux/kexec.h> #include <linux/crash_dump.h> +#include <linux/numa.h> #include <asm/ia32.h> #include <asm/machvec.h> @@ -494,9 +495,11 @@ setup_arch (char **cmdline_p) # ifdef CONFIG_ACPI_NUMA acpi_numa_init(); # endif + per_cpu_scan_finalize(4, additional_cpus); #else # ifdef CONFIG_SMP smp_build_cpu_map(); /* happens, e.g., with the Ski simulator */ + per_cpu_scan_finalize(num_possible_cpus(), additional_cpus); # endif #endif /* CONFIG_APCI_BOOT */ Index: per_cpu/arch/ia64/mm/discontig.c =================================================================== --- per_cpu.orig/arch/ia64/mm/discontig.c 2008-02-08 15:05:45.600746284 -0600 +++ per_cpu/arch/ia64/mm/discontig.c 2008-02-08 15:06:51.653423733 -0600 @@ -104,7 +104,7 @@ static int __meminit early_nr_cpus_node( { int cpu, n = 0; - for (cpu = 0; cpu < NR_CPUS; cpu++) + for_each_possible_early_cpu(cpu) if (node == node_cpuid[cpu].nid) n++; @@ -142,7 +142,7 @@ static void *per_cpu_node_setup(void *cp #ifdef CONFIG_SMP int cpu; - for (cpu = 0; cpu < NR_CPUS; cpu++) { + for_each_possible_early_cpu(cpu) { if (node == node_cpuid[cpu].nid) { memcpy(__va(cpu_data), __phys_per_cpu_start, __per_cpu_end - __per_cpu_start); @@ -345,7 +345,7 @@ static void __init initialize_pernode_da #ifdef CONFIG_SMP /* Set the node_data pointer for each per-cpu struct */ - for (cpu = 0; cpu < NR_CPUS; cpu++) { + for_each_possible_early_cpu(cpu) { node = node_cpuid[cpu].nid; per_cpu(cpu_info, cpu).node_data = mem_data[node].node_data; } @@ -493,13 +493,9 @@ void __cpuinit *per_cpu_init(void) int cpu; static int first_time = 1; - - if (smp_processor_id() != 0) - return __per_cpu_start + __per_cpu_offset[smp_processor_id()]; - if (first_time) { first_time = 0; - for (cpu = 0; cpu < NR_CPUS; cpu++) + for_each_possible_early_cpu(cpu) per_cpu(local_per_cpu_offset, cpu) = __per_cpu_offset[cpu]; } Index: per_cpu/arch/ia64/kernel/acpi.c =================================================================== --- per_cpu.orig/arch/ia64/kernel/acpi.c 2008-02-08 15:05:45.544738923 -0600 +++ per_cpu/arch/ia64/kernel/acpi.c 2008-02-08 15:06:51.669425834 -0600 @@ -482,6 +482,7 @@ acpi_numa_processor_affinity_init(struct (pa->apic_id << 8) | (pa->local_sapic_eid); /* nid should be overridden as logical node id later */ node_cpuid[srat_num_cpus].nid = pxm; + cpu_set(srat_num_cpus, early_cpu_possible_map); srat_num_cpus++; } @@ -559,8 +560,11 @@ void __init acpi_numa_arch_fixup(void) } /* set logical node id in cpu structure */ - for (i = 0; i < srat_num_cpus; i++) + for (i = 0; i < srat_num_cpus; i++) { + if (!cpu_isset(i, early_cpu_possible_map)) + continue; node_cpuid[i].nid = pxm_to_node(node_cpuid[i].nid); + } printk(KERN_INFO "Number of logical nodes in system = %d\n", num_online_nodes()); Index: per_cpu/arch/ia64/kernel/numa.c =================================================================== --- per_cpu.orig/arch/ia64/kernel/numa.c 2008-02-08 15:05:45.560741026 -0600 +++ per_cpu/arch/ia64/kernel/numa.c 2008-02-08 15:06:51.697429512 -0600 @@ -73,7 +73,7 @@ void __init build_cpu_to_node_map(void) for(node=0; node < MAX_NUMNODES; node++) cpus_clear(node_to_cpu_mask[node]); - for(cpu = 0; cpu < NR_CPUS; ++cpu) { + for_each_possible_early_cpu(cpu) { node = -1; for (i = 0; i < NR_CPUS; ++i) if (cpu_physical_id(cpu) == node_cpuid[i].phys_id) { Index: per_cpu/include/asm-ia64/acpi.h =================================================================== --- per_cpu.orig/include/asm-ia64/acpi.h 2008-02-08 15:05:53.685808838 -0600 +++ per_cpu/include/asm-ia64/acpi.h 2008-02-08 15:06:51.721432664 -0600 @@ -115,7 +115,11 @@ extern unsigned int is_cpu_cpei_target(u extern void set_cpei_target_cpu(unsigned int cpu); extern unsigned int get_cpei_target_cpu(void); extern void prefill_possible_map(void); +#ifdef CONFIG_ACPI_HOTPLUG_CPU extern int additional_cpus; +#else +#define additional_cpus 0 +#endif #ifdef CONFIG_ACPI_NUMA #if MAX_NUMNODES > 256 Index: per_cpu/include/asm-ia64/numa.h =================================================================== --- per_cpu.orig/include/asm-ia64/numa.h 2008-02-08 15:05:53.697810415 -0600 +++ per_cpu/include/asm-ia64/numa.h 2008-02-08 16:42:09.086660888 -0600 @@ -22,6 +22,8 @@ #include <asm/mmzone.h> +#define NUMA_NO_NODE -1 + extern u16 cpu_to_node_map[NR_CPUS] __cacheline_aligned; extern cpumask_t node_to_cpu_mask[MAX_NUMNODES] __cacheline_aligned; extern pg_data_t *pgdat_list[MAX_NUMNODES]; @@ -68,6 +70,26 @@ extern int paddr_to_nid(unsigned long pa extern void map_cpu_to_node(int cpu, int nid); extern void unmap_cpu_from_node(int cpu, int nid); +extern cpumask_t early_cpu_possible_map; +#define for_each_possible_early_cpu(cpu) \ + for_each_cpu_mask((cpu), early_cpu_possible_map) + +static inline void per_cpu_scan_finalize(int min_cpus, int reserve_cpus) +{ + int low_cpu, high_cpu; + int cpu; + + low_cpu = cpus_weight(early_cpu_possible_map); + + high_cpu = max(low_cpu, min_cpus); + high_cpu = min(high_cpu + reserve_cpus, NR_CPUS); + + for (cpu = low_cpu; cpu < high_cpu; cpu++) { + cpu_set(cpu, early_cpu_possible_map); + if (node_cpuid[cpu].nid == NUMA_NO_NODE) + node_cpuid[cpu].nid = 0; + } +} #else /* !CONFIG_NUMA */ #define map_cpu_to_node(cpu, nid) do{}while(0) @@ -75,6 +97,7 @@ extern void unmap_cpu_from_node(int cpu, #define paddr_to_nid(addr) 0 +static inline void per_cpu_scan_finalize(int min_cpus, int reserve_cpus) {}; #endif /* CONFIG_NUMA */ #endif /* _ASM_IA64_NUMA_H */ Index: per_cpu/arch/ia64/mm/numa.c =================================================================== --- per_cpu.orig/arch/ia64/mm/numa.c 2008-02-08 15:05:45.604746810 -0600 +++ per_cpu/arch/ia64/mm/numa.c 2008-02-08 16:41:43.675628259 -0600 @@ -27,7 +27,10 @@ */ int num_node_memblks; struct node_memblk_s node_memblk[NR_NODE_MEMBLKS]; -struct node_cpuid_s node_cpuid[NR_CPUS]; +struct node_cpuid_s node_cpuid[NR_CPUS] = + { [0 ... NR_CPUS-1] = { .phys_id = 0, .nid = NUMA_NO_NODE } }; +cpumask_t early_cpu_possible_map = CPU_MASK_NONE; + /* * This is a matrix with "distances" between nodes, they should be * proportional to the memory access latency ratios. - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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