From 155dd720d06a219ddf5a56b473cb3325441fc879 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 13 Mar 2009 14:49:53 +1030 Subject: [PATCH] cpumask: convert struct cpuinfo_x86's llc_shared_map to cpumask_var_t Impact: reduce kernel memory usage when CONFIG_CPUMASK_OFFSTACK=y Signed-off-by: Rusty Russell --- arch/x86/include/asm/processor.h | 2 +- arch/x86/kernel/smpboot.c | 33 +++++++++++++++++++++++++------- 2 files changed, 27 insertions(+), 8 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 76139506c3e4..d794d9483c56 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -94,7 +94,7 @@ struct cpuinfo_x86 { unsigned long loops_per_jiffy; #ifdef CONFIG_SMP /* cpus sharing the last level cache: */ - cpumask_t llc_shared_map; + cpumask_var_t llc_shared_map; #endif /* cpuid returned max cores value: */ u16 x86_max_cores; diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 5a58a45ac1e3..d6427aa56966 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -329,6 +329,23 @@ notrace static void __cpuinit start_secondary(void *unused) cpu_idle(); } +#ifdef CONFIG_CPUMASK_OFFSTACK +/* In this case, llc_shared_map is a pointer to a cpumask. */ +static inline void copy_cpuinfo_x86(struct cpuinfo_x86 *dst, + const struct cpuinfo_x86 *src) +{ + struct cpumask *llc = dst->llc_shared_map; + *dst = *src; + dst->llc_shared_map = llc; +} +#else +static inline void copy_cpuinfo_x86(struct cpuinfo_x86 *dst, + const struct cpuinfo_x86 *src) +{ + *dst = *src; +} +#endif /* CONFIG_CPUMASK_OFFSTACK */ + /* * The bootstrap kernel entry code has set these up. Save them for * a given CPU @@ -338,7 +355,7 @@ void __cpuinit smp_store_cpu_info(int id) { struct cpuinfo_x86 *c = &cpu_data(id); - *c = boot_cpu_data; + copy_cpuinfo_x86(c, &boot_cpu_data); c->cpu_index = id; if (id != 0) identify_secondary_cpu(c); @@ -362,15 +379,15 @@ void __cpuinit set_cpu_sibling_map(int cpu) cpumask_set_cpu(cpu, cpu_sibling_mask(i)); cpumask_set_cpu(i, cpu_core_mask(cpu)); cpumask_set_cpu(cpu, cpu_core_mask(i)); - cpumask_set_cpu(i, &c->llc_shared_map); - cpumask_set_cpu(cpu, &o->llc_shared_map); + cpumask_set_cpu(i, c->llc_shared_map); + cpumask_set_cpu(cpu, o->llc_shared_map); } } } else { cpumask_set_cpu(cpu, cpu_sibling_mask(cpu)); } - cpumask_set_cpu(cpu, &c->llc_shared_map); + cpumask_set_cpu(cpu, c->llc_shared_map); if (current_cpu_data.x86_max_cores == 1) { cpumask_copy(cpu_core_mask(cpu), cpu_sibling_mask(cpu)); @@ -381,8 +398,8 @@ void __cpuinit set_cpu_sibling_map(int cpu) for_each_cpu(i, cpu_sibling_setup_mask) { if (per_cpu(cpu_llc_id, cpu) != BAD_APICID && per_cpu(cpu_llc_id, cpu) == per_cpu(cpu_llc_id, i)) { - cpumask_set_cpu(i, &c->llc_shared_map); - cpumask_set_cpu(cpu, &cpu_data(i).llc_shared_map); + cpumask_set_cpu(i, c->llc_shared_map); + cpumask_set_cpu(cpu, cpu_data(i).llc_shared_map); } if (c->phys_proc_id == cpu_data(i).phys_proc_id) { cpumask_set_cpu(i, cpu_core_mask(cpu)); @@ -420,7 +437,7 @@ const struct cpumask *cpu_coregroup_mask(int cpu) if (sched_mc_power_savings || sched_smt_power_savings) return cpu_core_mask(cpu); else - return &c->llc_shared_map; + return c->llc_shared_map; } static void impress_friends(void) @@ -1039,8 +1056,10 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus) for_each_possible_cpu(i) { alloc_cpumask_var(&per_cpu(cpu_sibling_map, i), GFP_KERNEL); alloc_cpumask_var(&per_cpu(cpu_core_map, i), GFP_KERNEL); + alloc_cpumask_var(&cpu_data(i).llc_shared_map, GFP_KERNEL); cpumask_clear(per_cpu(cpu_core_map, i)); cpumask_clear(per_cpu(cpu_sibling_map, i)); + cpumask_clear(cpu_data(i).llc_shared_map); } set_cpu_sibling_map(0); -- 2.30.2