diff options
| -rw-r--r-- | arch/x86/kernel/setup_percpu.c | 4 | ||||
| -rw-r--r-- | include/linux/percpu.h | 7 | ||||
| -rw-r--r-- | mm/percpu.c | 113 |
3 files changed, 93 insertions, 31 deletions
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c index 9becc5d..67f6314 100644 --- a/arch/x86/kernel/setup_percpu.c +++ b/arch/x86/kernel/setup_percpu.c @@ -234,7 +234,9 @@ static int __init setup_pcpu_embed(bool chosen) return -EINVAL; return pcpu_embed_first_chunk(PERCPU_FIRST_CHUNK_RESERVE, - reserve - PERCPU_FIRST_CHUNK_RESERVE); + reserve - PERCPU_FIRST_CHUNK_RESERVE, + PAGE_SIZE, NULL, pcpu_fc_alloc, + pcpu_fc_free); } /* diff --git a/include/linux/percpu.h b/include/linux/percpu.h index a7ec840..2535993 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -110,8 +110,11 @@ extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, void *base_addr); #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK -extern int __init pcpu_embed_first_chunk(size_t reserved_size, - ssize_t dyn_size); +extern int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size, + size_t atom_size, + pcpu_fc_cpu_distance_fn_t cpu_distance_fn, + pcpu_fc_alloc_fn_t alloc_fn, + pcpu_fc_free_fn_t free_fn); #endif #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK diff --git a/mm/percpu.c b/mm/percpu.c index cc9c4c6..c2826d0 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1747,15 +1747,25 @@ early_param("percpu_alloc", percpu_alloc_setup); * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem * @reserved_size: the size of reserved percpu area in bytes * @dyn_size: free size for dynamic allocation in bytes, -1 for auto + * @atom_size: allocation atom size + * @cpu_distance_fn: callback to determine distance between cpus, optional + * @alloc_fn: function to allocate percpu page + * @free_fn: funtion to free percpu page * * This is a helper to ease setting up embedded first percpu chunk and * can be called where pcpu_setup_first_chunk() is expected. * * If this function is used to setup the first chunk, it is allocated - * as a contiguous area using bootmem allocator and used as-is without - * being mapped into vmalloc area. This enables the first chunk to - * piggy back on the linear physical mapping which often uses larger - * page size. + * by calling @alloc_fn and used as-is without being mapped into + * vmalloc area. Allocations are always whole multiples of @atom_size + * aligned to @atom_size. + * + * This enables the first chunk to piggy back on the linear physical + * mapping which often uses larger page size. Please note that this + * can result in very sparse cpu->unit mapping on NUMA machines thus + * requiring large vmalloc address space. Don't use this allocator if + * vmalloc space is not orders of magnitude larger than distances + * between node memory addresses (ie. 32bit NUMA machines). * * When @dyn_size is positive, dynamic area might be larger than * specified to fill page alignment. When @dyn_size is auto, @@ -1763,53 +1773,88 @@ early_param("percpu_alloc", percpu_alloc_setup); * and reserved areas. * * If the needed size is smaller than the minimum or specified unit - * size, the leftover is returned to the bootmem allocator. + * size, the leftover is returned using @free_fn. * * RETURNS: * 0 on success, -errno on failure. */ -int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size) +int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size, + size_t atom_size, + pcpu_fc_cpu_distance_fn_t cpu_distance_fn, + pcpu_fc_alloc_fn_t alloc_fn, + pcpu_fc_free_fn_t free_fn) { + void *base = (void *)ULONG_MAX; + void **areas = NULL; struct pcpu_alloc_info *ai; - size_t size_sum, chunk_size; - void *base; - int unit; - int rc; + size_t size_sum, areas_size; + int group, i, rc; - ai = pcpu_build_alloc_info(reserved_size, dyn_size, PAGE_SIZE, NULL); + ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, + cpu_distance_fn); if (IS_ERR(ai)) return PTR_ERR(ai); - BUG_ON(ai->nr_groups != 1); - BUG_ON(ai->groups[0].nr_units != num_possible_cpus()); size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; - chunk_size = ai->unit_size * num_possible_cpus(); + areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *)); - base = __alloc_bootmem_nopanic(chunk_size, PAGE_SIZE, - __pa(MAX_DMA_ADDRESS)); - if (!base) { - pr_warning("PERCPU: failed to allocate %zu bytes for " - "embedding\n", chunk_size); + areas = alloc_bootmem_nopanic(areas_size); + if (!areas) { rc = -ENOMEM; - goto out_free_ai; + goto out_free; } - /* return the leftover and copy */ - for (unit = 0; unit < num_possible_cpus(); unit++) { - void *ptr = base + unit * ai->unit_size; + /* allocate, copy and determine base address */ + for (group = 0; group < ai->nr_groups; group++) { + struct pcpu_group_info *gi = &ai->groups[group]; + unsigned int cpu = NR_CPUS; + void *ptr; + + for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++) + cpu = gi->cpu_map[i]; + BUG_ON(cpu == NR_CPUS); + + /* allocate space for the whole group */ + ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size); + if (!ptr) { + rc = -ENOMEM; + goto out_free_areas; + } + areas[group] = ptr; - free_bootmem(__pa(ptr + size_sum), ai->unit_size - size_sum); - memcpy(ptr, __per_cpu_load, ai->static_size); + base = min(ptr, base); + + for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) { + if (gi->cpu_map[i] == NR_CPUS) { + /* unused unit, free whole */ + free_fn(ptr, ai->unit_size); + continue; + } + /* copy and return the unused part */ + memcpy(ptr, __per_cpu_load, ai->static_size); + free_fn(ptr + size_sum, ai->unit_size - size_sum); + } } - /* we're ready, commit */ + /* base address is now known, determine group base offsets */ + for (group = 0; group < ai->nr_groups; group++) + ai->groups[group].base_offset = areas[group] - base; + pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n", PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size, ai->dyn_size, ai->unit_size); rc = pcpu_setup_first_chunk(ai, base); -out_free_ai: + goto out_free; + +out_free_areas: + for (group = 0; group < ai->nr_groups; group++) + free_fn(areas[group], + ai->groups[group].nr_units * ai->unit_size); +out_free: pcpu_free_alloc_info(ai); + if (areas) + free_bootmem(__pa(areas), areas_size); return rc; } #endif /* CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK || @@ -2177,6 +2222,17 @@ void *pcpu_lpage_remapped(void *kaddr) unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; EXPORT_SYMBOL(__per_cpu_offset); +static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size, + size_t align) +{ + return __alloc_bootmem_nopanic(size, align, __pa(MAX_DMA_ADDRESS)); +} + +static void __init pcpu_dfl_fc_free(void *ptr, size_t size) +{ + free_bootmem(__pa(ptr), size); +} + void __init setup_per_cpu_areas(void) { unsigned long delta; @@ -2188,7 +2244,8 @@ void __init setup_per_cpu_areas(void) * what the legacy allocator did. */ rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, - PERCPU_DYNAMIC_RESERVE); + PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, + pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); if (rc < 0) panic("Failed to initialized percpu areas."); |
