From: Tejun Heo Date: Fri, 3 Jul 2009 23:10:59 +0000 (+0900) Subject: x86,percpu: generalize 4k first chunk allocator X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d4b95f80399471e4bce5e992700ff7f06ef91f6a;p=linux-beck.git x86,percpu: generalize 4k first chunk allocator Generalize and move x86 setup_pcpu_4k() into pcpu_4k_first_chunk(). setup_pcpu_4k() now is a simple wrapper around the generalized version. Other than taking size parameters and using arch supplied callbacks to allocate/free memory, pcpu_4k_first_chunk() is identical to the original implementation. This simplifies arch code and will help converting more archs to dynamic percpu allocator. While at it, s/pcpu_populate_pte_fn_t/pcpu_fc_populate_pte_fn_t/ for consistency. [ Impact: code reorganization and generalization ] Signed-off-by: Tejun Heo Cc: Ingo Molnar --- diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index 14728206fb52..ab896b31e80b 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -123,6 +123,19 @@ static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size, #endif } +/* + * Helpers for first chunk memory allocation + */ +static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size) +{ + return pcpu_alloc_bootmem(cpu, size, size); +} + +static void __init pcpu_fc_free(void *ptr, size_t size) +{ + free_bootmem(__pa(ptr), size); +} + /* * Large page remap allocator * @@ -346,22 +359,11 @@ static ssize_t __init setup_pcpu_embed(size_t static_size, bool chosen) } /* - * 4k page allocator + * 4k 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. + * Boring fallback 4k allocator. This allocator puts more pressure on + * PTE TLBs but other than that behaves nicely on both UMA and NUMA. */ -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) { populate_extra_pte(addr); @@ -369,51 +371,9 @@ static void __init pcpu4k_populate_pte(unsigned long 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 * num_possible_cpus() - * 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; + return pcpu_4k_first_chunk(static_size, PERCPU_FIRST_CHUNK_RESERVE, + pcpu_fc_alloc, pcpu_fc_free, + pcpu4k_populate_pte); } /* for explicit first chunk allocator selection */ diff --git a/include/linux/percpu.h b/include/linux/percpu.h index 83bff053bd1c..41b5bfab4195 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -59,18 +59,26 @@ extern void *pcpu_base_addr; typedef struct page * (*pcpu_get_page_fn_t)(unsigned int cpu, int pageno); -typedef void (*pcpu_populate_pte_fn_t)(unsigned long addr); +typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size); +typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size); +typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr); extern size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, size_t static_size, size_t reserved_size, ssize_t dyn_size, ssize_t unit_size, void *base_addr, - pcpu_populate_pte_fn_t populate_pte_fn); + pcpu_fc_populate_pte_fn_t populate_pte_fn); extern ssize_t __init pcpu_embed_first_chunk( size_t static_size, size_t reserved_size, ssize_t dyn_size); +extern ssize_t __init pcpu_4k_first_chunk( + size_t static_size, size_t reserved_size, + pcpu_fc_alloc_fn_t alloc_fn, + pcpu_fc_free_fn_t free_fn, + pcpu_fc_populate_pte_fn_t populate_pte_fn); + /* * Use this to get to a cpu's version of the per-cpu object * dynamically allocated. Non-atomic access to the current CPU's diff --git a/mm/percpu.c b/mm/percpu.c index fc6babe6e554..27b0f40a3ea8 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1037,7 +1037,7 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, size_t static_size, size_t reserved_size, ssize_t dyn_size, ssize_t unit_size, void *base_addr, - pcpu_populate_pte_fn_t populate_pte_fn) + pcpu_fc_populate_pte_fn_t populate_pte_fn) { static struct vm_struct first_vm; static int smap[2], dmap[2]; @@ -1270,6 +1270,89 @@ ssize_t __init pcpu_embed_first_chunk(size_t static_size, size_t reserved_size, pcpue_unit_size, pcpue_ptr, NULL); } +/* + * 4k page first chunk setup helper. + */ +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; +} + +/** + * pcpu_4k_first_chunk - map the first chunk using PAGE_SIZE pages + * @static_size: the size of static percpu area in bytes + * @reserved_size: the size of reserved percpu area in bytes + * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE + * @free_fn: funtion to free percpu page, always called with PAGE_SIZE + * @populate_pte_fn: function to populate pte + * + * This is a helper to ease setting up embedded first percpu chunk and + * can be called where pcpu_setup_first_chunk() is expected. + * + * This is the basic allocator. Static percpu area is allocated + * page-by-page into vmalloc area. + * + * RETURNS: + * The determined pcpu_unit_size which can be used to initialize + * percpu access on success, -errno on failure. + */ +ssize_t __init pcpu_4k_first_chunk(size_t static_size, size_t reserved_size, + pcpu_fc_alloc_fn_t alloc_fn, + pcpu_fc_free_fn_t free_fn, + pcpu_fc_populate_pte_fn_t populate_pte_fn) +{ + 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 * num_possible_cpus() * + 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 = alloc_fn(cpu, 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, + reserved_size, -1, + -1, NULL, populate_pte_fn); + goto out_free_ar; + +enomem: + while (--j >= 0) + free_fn(page_address(pcpu4k_pages[j]), PAGE_SIZE); + ret = -ENOMEM; +out_free_ar: + free_bootmem(__pa(pcpu4k_pages), pages_size); + return ret; +} + /* * Generic percpu area setup. *