diff options
Diffstat (limited to 'arch/x86/kernel/setup_percpu.c')
| -rw-r--r-- | arch/x86/kernel/setup_percpu.c | 364 |
1 files changed, 45 insertions, 319 deletions
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index 07d81916f212..d559af913e1f 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -55,6 +55,7 @@ EXPORT_SYMBOL(__per_cpu_offset); #define PERCPU_FIRST_CHUNK_RESERVE 0 #endif +#ifdef CONFIG_X86_32 /** * pcpu_need_numa - determine percpu allocation needs to consider NUMA * @@ -83,6 +84,7 @@ static bool __init pcpu_need_numa(void) #endif return false; } +#endif /** * pcpu_alloc_bootmem - NUMA friendly alloc_bootmem wrapper for percpu @@ -124,308 +126,35 @@ static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size, } /* - * Large page remap allocator - * - * This allocator uses PMD page as unit. A PMD page is allocated for - * each cpu and each is remapped into vmalloc area using PMD mapping. - * As PMD page is quite large, only part of it is used for the first - * chunk. Unused part is returned to the bootmem allocator. - * - * So, the PMD pages are mapped twice - once to the physical mapping - * and to the vmalloc area for the first percpu chunk. The double - * mapping does add one more PMD TLB entry pressure but still is much - * better than only using 4k mappings while still being NUMA friendly. + * Helpers for first chunk memory allocation */ -#ifdef CONFIG_NEED_MULTIPLE_NODES -struct pcpul_ent { - unsigned int cpu; - void *ptr; -}; - -static size_t pcpul_size; -static struct pcpul_ent *pcpul_map; -static struct vm_struct pcpul_vm; - -static struct page * __init pcpul_get_page(unsigned int cpu, int pageno) +static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align) { - size_t off = (size_t)pageno << PAGE_SHIFT; - - if (off >= pcpul_size) - return NULL; - - return virt_to_page(pcpul_map[cpu].ptr + off); + return pcpu_alloc_bootmem(cpu, size, align); } -static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen) +static void __init pcpu_fc_free(void *ptr, size_t size) { - size_t map_size, dyn_size; - unsigned int cpu; - int i, j; - ssize_t ret; - - if (!chosen) { - size_t vm_size = VMALLOC_END - VMALLOC_START; - size_t tot_size = nr_cpu_ids * PMD_SIZE; - - /* on non-NUMA, embedding is better */ - if (!pcpu_need_numa()) - return -EINVAL; - - /* don't consume more than 20% of vmalloc area */ - if (tot_size > vm_size / 5) { - pr_info("PERCPU: too large chunk size %zuMB for " - "large page remap\n", tot_size >> 20); - return -EINVAL; - } - } - - /* need PSE */ - if (!cpu_has_pse) { - pr_warning("PERCPU: lpage allocator requires PSE\n"); - return -EINVAL; - } - - /* - * Currently supports only single page. Supporting multiple - * pages won't be too difficult if it ever becomes necessary. - */ - pcpul_size = PFN_ALIGN(static_size + PERCPU_MODULE_RESERVE + - PERCPU_DYNAMIC_RESERVE); - if (pcpul_size > PMD_SIZE) { - pr_warning("PERCPU: static data is larger than large page, " - "can't use large page\n"); - return -EINVAL; - } - dyn_size = pcpul_size - static_size - PERCPU_FIRST_CHUNK_RESERVE; - - /* allocate pointer array and alloc large pages */ - map_size = PFN_ALIGN(nr_cpu_ids * sizeof(pcpul_map[0])); - pcpul_map = alloc_bootmem(map_size); - - for_each_possible_cpu(cpu) { - pcpul_map[cpu].cpu = cpu; - pcpul_map[cpu].ptr = pcpu_alloc_bootmem(cpu, PMD_SIZE, - PMD_SIZE); - if (!pcpul_map[cpu].ptr) { - pr_warning("PERCPU: failed to allocate large page " - "for cpu%u\n", cpu); - goto enomem; - } - - /* - * Only use pcpul_size bytes and give back the rest. - * - * Ingo: The 2MB up-rounding bootmem is needed to make - * sure the partial 2MB page is still fully RAM - it's - * not well-specified to have a PAT-incompatible area - * (unmapped RAM, device memory, etc.) in that hole. - */ - free_bootmem(__pa(pcpul_map[cpu].ptr + pcpul_size), - PMD_SIZE - pcpul_size); - - memcpy(pcpul_map[cpu].ptr, __per_cpu_load, static_size); - } - - /* allocate address and map */ - pcpul_vm.flags = VM_ALLOC; - pcpul_vm.size = nr_cpu_ids * PMD_SIZE; - vm_area_register_early(&pcpul_vm, PMD_SIZE); - - for_each_possible_cpu(cpu) { - pmd_t *pmd, pmd_v; - - pmd = populate_extra_pmd((unsigned long)pcpul_vm.addr + - cpu * PMD_SIZE); - pmd_v = pfn_pmd(page_to_pfn(virt_to_page(pcpul_map[cpu].ptr)), - PAGE_KERNEL_LARGE); - set_pmd(pmd, pmd_v); - } - - /* we're ready, commit */ - pr_info("PERCPU: Remapped at %p with large pages, static data " - "%zu bytes\n", pcpul_vm.addr, static_size); - - ret = pcpu_setup_first_chunk(pcpul_get_page, static_size, - PERCPU_FIRST_CHUNK_RESERVE, dyn_size, - PMD_SIZE, pcpul_vm.addr, NULL); - - /* sort pcpul_map array for pcpu_lpage_remapped() */ - for (i = 0; i < nr_cpu_ids - 1; i++) - for (j = i + 1; j < nr_cpu_ids; j++) - if (pcpul_map[i].ptr > pcpul_map[j].ptr) { - struct pcpul_ent tmp = pcpul_map[i]; - pcpul_map[i] = pcpul_map[j]; - pcpul_map[j] = tmp; - } - - return ret; - -enomem: - for_each_possible_cpu(cpu) - if (pcpul_map[cpu].ptr) - free_bootmem(__pa(pcpul_map[cpu].ptr), pcpul_size); - free_bootmem(__pa(pcpul_map), map_size); - return -ENOMEM; + free_bootmem(__pa(ptr), size); } -/** - * pcpu_lpage_remapped - determine whether a kaddr is in pcpul recycled area - * @kaddr: the kernel address in question - * - * Determine whether @kaddr falls in the pcpul recycled area. This is - * used by pageattr to detect VM aliases and break up the pcpu PMD - * mapping such that the same physical page is not mapped under - * different attributes. - * - * The recycled area is always at the tail of a partially used PMD - * page. - * - * RETURNS: - * Address of corresponding remapped pcpu address if match is found; - * otherwise, NULL. - */ -void *pcpu_lpage_remapped(void *kaddr) +static int __init pcpu_cpu_distance(unsigned int from, unsigned int to) { - void *pmd_addr = (void *)((unsigned long)kaddr & PMD_MASK); - unsigned long offset = (unsigned long)kaddr & ~PMD_MASK; - int left = 0, right = nr_cpu_ids - 1; - int pos; - - /* pcpul in use at all? */ - if (!pcpul_map) - return NULL; - - /* okay, perform binary search */ - while (left <= right) { - pos = (left + right) / 2; - - if (pcpul_map[pos].ptr < pmd_addr) - left = pos + 1; - else if (pcpul_map[pos].ptr > pmd_addr) - right = pos - 1; - else { - /* it shouldn't be in the area for the first chunk */ - WARN_ON(offset < pcpul_size); - - return pcpul_vm.addr + - pcpul_map[pos].cpu * PMD_SIZE + offset; - } - } - - return NULL; -} +#ifdef CONFIG_NEED_MULTIPLE_NODES + if (early_cpu_to_node(from) == early_cpu_to_node(to)) + return LOCAL_DISTANCE; + else + return REMOTE_DISTANCE; #else -static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen) -{ - return -EINVAL; -} + return LOCAL_DISTANCE; #endif - -/* - * Embedding allocator - * - * The first chunk is sized to just contain the static area plus - * module and dynamic reserves and embedded into linear physical - * mapping so that it can use PMD mapping without additional TLB - * pressure. - */ -static ssize_t __init setup_pcpu_embed(size_t static_size, bool chosen) -{ - size_t reserve = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE; - - /* - * If large page isn't supported, there's no benefit in doing - * this. Also, embedding allocation doesn't play well with - * NUMA. - */ - if (!chosen && (!cpu_has_pse || pcpu_need_numa())) - return -EINVAL; - - return pcpu_embed_first_chunk(static_size, PERCPU_FIRST_CHUNK_RESERVE, - reserve - PERCPU_FIRST_CHUNK_RESERVE, -1); } -/* - * 4k page allocator - * - * This is the basic allocator. Static percpu area is allocated - * page-by-page and most of initialization is done by the generic - * setup function. - */ -static struct page **pcpu4k_pages __initdata; -static int pcpu4k_nr_static_pages __initdata; - -static struct page * __init pcpu4k_get_page(unsigned int cpu, int pageno) -{ - if (pageno < pcpu4k_nr_static_pages) - return pcpu4k_pages[cpu * pcpu4k_nr_static_pages + pageno]; - return NULL; -} - -static void __init pcpu4k_populate_pte(unsigned long addr) +static void __init pcpup_populate_pte(unsigned long addr) { populate_extra_pte(addr); } -static ssize_t __init setup_pcpu_4k(size_t static_size) -{ - size_t pages_size; - unsigned int cpu; - int i, j; - ssize_t ret; - - pcpu4k_nr_static_pages = PFN_UP(static_size); - - /* unaligned allocations can't be freed, round up to page size */ - pages_size = PFN_ALIGN(pcpu4k_nr_static_pages * nr_cpu_ids - * sizeof(pcpu4k_pages[0])); - pcpu4k_pages = alloc_bootmem(pages_size); - - /* allocate and copy */ - j = 0; - for_each_possible_cpu(cpu) - for (i = 0; i < pcpu4k_nr_static_pages; i++) { - void *ptr; - - ptr = pcpu_alloc_bootmem(cpu, PAGE_SIZE, PAGE_SIZE); - if (!ptr) { - pr_warning("PERCPU: failed to allocate " - "4k page for cpu%u\n", cpu); - goto enomem; - } - - memcpy(ptr, __per_cpu_load + i * PAGE_SIZE, PAGE_SIZE); - pcpu4k_pages[j++] = virt_to_page(ptr); - } - - /* we're ready, commit */ - pr_info("PERCPU: Allocated %d 4k pages, static data %zu bytes\n", - pcpu4k_nr_static_pages, static_size); - - ret = pcpu_setup_first_chunk(pcpu4k_get_page, static_size, - PERCPU_FIRST_CHUNK_RESERVE, -1, - -1, NULL, pcpu4k_populate_pte); - goto out_free_ar; - -enomem: - while (--j >= 0) - free_bootmem(__pa(page_address(pcpu4k_pages[j])), PAGE_SIZE); - ret = -ENOMEM; -out_free_ar: - free_bootmem(__pa(pcpu4k_pages), pages_size); - return ret; -} - -/* for explicit first chunk allocator selection */ -static char pcpu_chosen_alloc[16] __initdata; - -static int __init percpu_alloc_setup(char *str) -{ - strncpy(pcpu_chosen_alloc, str, sizeof(pcpu_chosen_alloc) - 1); - return 0; -} -early_param("percpu_alloc", percpu_alloc_setup); - static inline void setup_percpu_segment(int cpu) { #ifdef CONFIG_X86_32 @@ -441,52 +170,49 @@ static inline void setup_percpu_segment(int cpu) void __init setup_per_cpu_areas(void) { - size_t static_size = __per_cpu_end - __per_cpu_start; unsigned int cpu; unsigned long delta; - size_t pcpu_unit_size; - ssize_t ret; + int rc; pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n", NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids); /* - * Allocate percpu area. If PSE is supported, try to make use - * of large page mappings. Please read comments on top of - * each allocator for details. + * Allocate percpu area. Embedding allocator is our favorite; + * however, on NUMA configurations, it can result in very + * sparse unit mapping and vmalloc area isn't spacious enough + * on 32bit. Use page in that case. */ - ret = -EINVAL; - if (strlen(pcpu_chosen_alloc)) { - if (strcmp(pcpu_chosen_alloc, "4k")) { - if (!strcmp(pcpu_chosen_alloc, "lpage")) - ret = setup_pcpu_lpage(static_size, true); - else if (!strcmp(pcpu_chosen_alloc, "embed")) - ret = setup_pcpu_embed(static_size, true); - else - pr_warning("PERCPU: unknown allocator %s " - "specified\n", pcpu_chosen_alloc); - if (ret < 0) - pr_warning("PERCPU: %s allocator failed (%zd), " - "falling back to 4k\n", - pcpu_chosen_alloc, ret); - } - } else { - ret = setup_pcpu_lpage(static_size, false); - if (ret < 0) - ret = setup_pcpu_embed(static_size, false); +#ifdef CONFIG_X86_32 + if (pcpu_chosen_fc == PCPU_FC_AUTO && pcpu_need_numa()) + pcpu_chosen_fc = PCPU_FC_PAGE; +#endif + rc = -EINVAL; + if (pcpu_chosen_fc != PCPU_FC_PAGE) { + const size_t atom_size = cpu_has_pse ? PMD_SIZE : PAGE_SIZE; + const size_t dyn_size = PERCPU_MODULE_RESERVE + + PERCPU_DYNAMIC_RESERVE - PERCPU_FIRST_CHUNK_RESERVE; + + rc = pcpu_embed_first_chunk(PERCPU_FIRST_CHUNK_RESERVE, + dyn_size, atom_size, + pcpu_cpu_distance, + pcpu_fc_alloc, pcpu_fc_free); + if (rc < 0) + pr_warning("PERCPU: %s allocator failed (%d), " + "falling back to page size\n", + pcpu_fc_names[pcpu_chosen_fc], rc); } - if (ret < 0) - ret = setup_pcpu_4k(static_size); - if (ret < 0) - panic("cannot allocate static percpu area (%zu bytes, err=%zd)", - static_size, ret); - - pcpu_unit_size = ret; + if (rc < 0) + rc = pcpu_page_first_chunk(PERCPU_FIRST_CHUNK_RESERVE, + pcpu_fc_alloc, pcpu_fc_free, + pcpup_populate_pte); + if (rc < 0) + panic("cannot initialize percpu area (err=%d)", rc); /* alrighty, percpu areas up and running */ delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; for_each_possible_cpu(cpu) { - per_cpu_offset(cpu) = delta + cpu * pcpu_unit_size; + per_cpu_offset(cpu) = delta + pcpu_unit_offsets[cpu]; per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu); per_cpu(cpu_number, cpu) = cpu; setup_percpu_segment(cpu); |