From 3461b0af025251bbc6b3d56c821c6ac2de6f7209 Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Mon, 12 May 2008 21:21:13 +0200 Subject: x86: remove static boot_cpu_pda array v2 * Remove the boot_cpu_pda array and pointer table from the data section. Allocate the pointer table and array during init. do_boot_cpu() will reallocate the pda in node local memory and if the cpu is being brought up before the bootmem array is released (after_bootmem = 0), then it will free the initial pda. This will happen for all cpus present at system startup. This removes 512k + 32k bytes from the data section. 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/kernel/head64.c | 26 +++++++++++++++-- arch/x86/kernel/setup.c | 73 ++++++++++++++++++++++++++++++++++++----------- arch/x86/kernel/setup64.c | 8 ++++-- arch/x86/kernel/smpboot.c | 59 +++++++++++++++++++++++++++++--------- 4 files changed, 131 insertions(+), 35 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index e25c57b8aa8..0ab59edd706 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -25,6 +25,24 @@ #include #include +/* boot cpu pda */ +static struct x8664_pda _boot_cpu_pda __read_mostly; + +#ifdef CONFIG_SMP +#ifdef CONFIG_DEBUG_PER_CPU_MAPS +/* + * We install an empty cpu_pda pointer table to trap references before + * the actual cpu_pda pointer table is created in setup_cpu_pda_map(). + */ +static struct x8664_pda *__cpu_pda[NR_CPUS] __initdata; +#else +static struct x8664_pda *__cpu_pda[1] __read_mostly; +#endif + +#else /* !CONFIG_SMP (NR_CPUS will be 1) */ +static struct x8664_pda *__cpu_pda[NR_CPUS] __read_mostly; +#endif + static void __init zap_identity_mappings(void) { pgd_t *pgd = pgd_offset_k(0UL); @@ -156,10 +174,12 @@ void __init x86_64_start_kernel(char * real_mode_data) early_printk("Kernel alive\n"); - for (i = 0; i < NR_CPUS; i++) - cpu_pda(i) = &boot_cpu_pda[i]; - + _cpu_pda = __cpu_pda; + cpu_pda(0) = &_boot_cpu_pda; pda_init(0); + + early_printk("Kernel really alive\n"); + copy_bootdata(__va(real_mode_data)); reserve_early(__pa_symbol(&_text), __pa_symbol(&_end), "TEXT DATA BSS"); diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 913af838c3c..dd12c1c84a8 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -101,6 +101,50 @@ static inline void setup_cpumask_of_cpu(void) { } */ unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; EXPORT_SYMBOL(__per_cpu_offset); +static inline void setup_cpu_pda_map(void) { } + +#elif !defined(CONFIG_SMP) +static inline void setup_cpu_pda_map(void) { } + +#else /* CONFIG_SMP && CONFIG_X86_64 */ + +/* + * Allocate cpu_pda pointer table and array via alloc_bootmem. + */ +static void __init setup_cpu_pda_map(void) +{ + char *pda; + struct x8664_pda **new_cpu_pda; + unsigned long size; + int cpu; + + size = roundup(sizeof(struct x8664_pda), cache_line_size()); + + /* allocate cpu_pda array and pointer table */ + { + unsigned long tsize = nr_cpu_ids * sizeof(void *); + unsigned long asize = size * (nr_cpu_ids - 1); + + tsize = roundup(tsize, cache_line_size()); + new_cpu_pda = alloc_bootmem(tsize + asize); + pda = (char *)new_cpu_pda + tsize; + } + + /* initialize pointer table to static pda's */ + for_each_possible_cpu(cpu) { + if (cpu == 0) { + /* leave boot cpu pda in place */ + new_cpu_pda[0] = cpu_pda(0); + continue; + } + new_cpu_pda[cpu] = (struct x8664_pda *)pda; + new_cpu_pda[cpu]->in_bootmem = 1; + pda += size; + } + + /* point to new pointer table */ + _cpu_pda = new_cpu_pda; +} #endif /* @@ -110,46 +154,43 @@ EXPORT_SYMBOL(__per_cpu_offset); */ void __init setup_per_cpu_areas(void) { - int i, highest_cpu = 0; - unsigned long size; + ssize_t size = PERCPU_ENOUGH_ROOM; + char *ptr; + int cpu; #ifdef CONFIG_HOTPLUG_CPU prefill_possible_map(); +#else + nr_cpu_ids = num_processors; #endif + /* Setup cpu_pda map */ + setup_cpu_pda_map(); + /* Copy section for each CPU (we discard the original) */ size = PERCPU_ENOUGH_ROOM; printk(KERN_INFO "PERCPU: Allocating %lu bytes of per cpu data\n", size); - for_each_possible_cpu(i) { - char *ptr; + for_each_possible_cpu(cpu) { #ifndef CONFIG_NEED_MULTIPLE_NODES ptr = alloc_bootmem_pages(size); #else - int node = early_cpu_to_node(i); + int node = early_cpu_to_node(cpu); if (!node_online(node) || !NODE_DATA(node)) { ptr = alloc_bootmem_pages(size); printk(KERN_INFO "cpu %d has no node %d or node-local memory\n", - i, node); + cpu, node); } else ptr = alloc_bootmem_pages_node(NODE_DATA(node), size); #endif - if (!ptr) - panic("Cannot allocate cpu data for CPU %d\n", i); -#ifdef CONFIG_X86_64 - cpu_pda(i)->data_offset = ptr - __per_cpu_start; -#else - __per_cpu_offset[i] = ptr - __per_cpu_start; -#endif + per_cpu_offset(cpu) = ptr - __per_cpu_start; memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start); - highest_cpu = i; } - nr_cpu_ids = highest_cpu + 1; printk(KERN_DEBUG "NR_CPUS: %d, nr_cpu_ids: %d, nr_node_ids %d\n", NR_CPUS, nr_cpu_ids, nr_node_ids); @@ -199,7 +240,7 @@ void __cpuinit numa_set_node(int cpu, int node) { int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map); - if (node != NUMA_NO_NODE) + if (cpu_pda(cpu) && node != NUMA_NO_NODE) cpu_pda(cpu)->nodenumber = node; if (cpu_to_node_map) diff --git a/arch/x86/kernel/setup64.c b/arch/x86/kernel/setup64.c index aee0e820077..631ea6cc01d 100644 --- a/arch/x86/kernel/setup64.c +++ b/arch/x86/kernel/setup64.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -34,9 +35,8 @@ struct boot_params boot_params; cpumask_t cpu_initialized __cpuinitdata = CPU_MASK_NONE; -struct x8664_pda *_cpu_pda[NR_CPUS] __read_mostly; +struct x8664_pda **_cpu_pda __read_mostly; EXPORT_SYMBOL(_cpu_pda); -struct x8664_pda boot_cpu_pda[NR_CPUS] __cacheline_aligned; struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table }; @@ -114,8 +114,10 @@ void pda_init(int cpu) __get_free_pages(GFP_ATOMIC, IRQSTACK_ORDER); if (!pda->irqstackptr) panic("cannot allocate irqstack for cpu %d", cpu); - } + if (pda->nodenumber == 0 && cpu_to_node(cpu) != NUMA_NO_NODE) + pda->nodenumber = cpu_to_node(cpu); + } pda->irqstackptr += IRQSTACKSIZE-64; } diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 036604d3dae..bf083348745 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -816,6 +816,43 @@ static void __cpuinit do_fork_idle(struct work_struct *work) complete(&c_idle->done); } +/* + * Allocate node local memory for the AP pda. + * + * Must be called after the _cpu_pda pointer table is initialized. + */ +static int __cpuinit get_local_pda(int cpu) +{ + struct x8664_pda *oldpda, *newpda; + unsigned long size = sizeof(struct x8664_pda); + int node = cpu_to_node(cpu); + + if (cpu_pda(cpu) && !cpu_pda(cpu)->in_bootmem) + return 0; + + oldpda = cpu_pda(cpu); + newpda = kmalloc_node(size, GFP_ATOMIC, node); + if (!newpda) { + printk(KERN_ERR "Could not allocate node local PDA " + "for CPU %d on node %d\n", cpu, node); + + if (oldpda) + return 0; /* have a usable pda */ + else + return -1; + } + + if (oldpda) { + memcpy(newpda, oldpda, size); + if (!after_bootmem) + free_bootmem((unsigned long)oldpda, size); + } + + newpda->in_bootmem = 0; + cpu_pda(cpu) = newpda; + return 0; +} + static int __cpuinit do_boot_cpu(int apicid, int cpu) /* * NOTE - on most systems this is a PHYSICAL apic ID, but on multiquad @@ -841,19 +878,11 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu) } /* Allocate node local memory for AP pdas */ - if (cpu_pda(cpu) == &boot_cpu_pda[cpu]) { - struct x8664_pda *newpda, *pda; - int node = cpu_to_node(cpu); - pda = cpu_pda(cpu); - newpda = kmalloc_node(sizeof(struct x8664_pda), GFP_ATOMIC, - node); - if (newpda) { - memcpy(newpda, pda, sizeof(struct x8664_pda)); - cpu_pda(cpu) = newpda; - } else - printk(KERN_ERR - "Could not allocate node local PDA for CPU %d on node %d\n", - cpu, node); + if (cpu > 0) { + boot_error = get_local_pda(cpu); + if (boot_error) + goto restore_state; + /* if can't get pda memory, can't start cpu */ } #endif @@ -972,6 +1001,8 @@ do_rest: } } +restore_state: + if (boot_error) { /* Try to put things back the way they were before ... */ unmap_cpu_to_logical_apicid(cpu); @@ -1347,6 +1378,8 @@ __init void prefill_possible_map(void) for (i = 0; i < possible; i++) cpu_set(i, cpu_possible_map); + + nr_cpu_ids = possible; } static void __ref remove_cpu_from_maps(int cpu) -- cgit v1.2.3