diff options
Diffstat (limited to 'mm/percpu.c')
| -rw-r--r-- | mm/percpu.c | 339 |
1 files changed, 172 insertions, 167 deletions
diff --git a/mm/percpu.c b/mm/percpu.c index 3316e3aac7ee..2b9c4b2a2fc0 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1231,6 +1231,178 @@ void free_percpu(void *ptr) } EXPORT_SYMBOL_GPL(free_percpu); +static inline size_t pcpu_calc_fc_sizes(size_t static_size, + size_t reserved_size, + ssize_t *dyn_sizep) +{ + size_t size_sum; + + size_sum = PFN_ALIGN(static_size + reserved_size + + (*dyn_sizep >= 0 ? *dyn_sizep : 0)); + if (*dyn_sizep != 0) + *dyn_sizep = size_sum - static_size - reserved_size; + + return size_sum; +} + +#ifdef CONFIG_NEED_PER_CPU_LPAGE_FIRST_CHUNK +/** + * pcpu_lpage_build_unit_map - build unit_map for large page remapping + * @reserved_size: the size of reserved percpu area in bytes + * @dyn_sizep: in/out parameter for dynamic size, -1 for auto + * @unit_sizep: out parameter for unit size + * @unit_map: unit_map to be filled + * @cpu_distance_fn: callback to determine distance between cpus + * + * This function builds cpu -> unit map and determine other parameters + * considering needed percpu size, large page size and distances + * between CPUs in NUMA. + * + * CPUs which are of LOCAL_DISTANCE both ways are grouped together and + * may share units in the same large page. The returned configuration + * is guaranteed to have CPUs on different nodes on different large + * pages and >=75% usage of allocated virtual address space. + * + * RETURNS: + * On success, fills in @unit_map, sets *@dyn_sizep, *@unit_sizep and + * returns the number of units to be allocated. -errno on failure. + */ +int __init pcpu_lpage_build_unit_map(size_t reserved_size, ssize_t *dyn_sizep, + size_t *unit_sizep, size_t lpage_size, + int *unit_map, + pcpu_fc_cpu_distance_fn_t cpu_distance_fn) +{ + static int group_map[NR_CPUS] __initdata; + static int group_cnt[NR_CPUS] __initdata; + const size_t static_size = __per_cpu_end - __per_cpu_start; + int group_cnt_max = 0; + size_t size_sum, min_unit_size, alloc_size; + int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ + int last_allocs; + unsigned int cpu, tcpu; + int group, unit; + + /* + * Determine min_unit_size, alloc_size and max_upa such that + * alloc_size is multiple of lpage_size and is the smallest + * which can accomodate 4k aligned segments which are equal to + * or larger than min_unit_size. + */ + size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, dyn_sizep); + min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); + + alloc_size = roundup(min_unit_size, lpage_size); + upa = alloc_size / min_unit_size; + while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) + upa--; + max_upa = upa; + + /* group cpus according to their proximity */ + for_each_possible_cpu(cpu) { + group = 0; + next_group: + for_each_possible_cpu(tcpu) { + if (cpu == tcpu) + break; + if (group_map[tcpu] == group && + (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || + cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { + group++; + goto next_group; + } + } + group_map[cpu] = group; + group_cnt[group]++; + group_cnt_max = max(group_cnt_max, group_cnt[group]); + } + + /* + * Expand unit size until address space usage goes over 75% + * and then as much as possible without using more address + * space. + */ + last_allocs = INT_MAX; + for (upa = max_upa; upa; upa--) { + int allocs = 0, wasted = 0; + + if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) + continue; + + for (group = 0; group_cnt[group]; group++) { + int this_allocs = DIV_ROUND_UP(group_cnt[group], upa); + allocs += this_allocs; + wasted += this_allocs * upa - group_cnt[group]; + } + + /* + * Don't accept if wastage is over 25%. The + * greater-than comparison ensures upa==1 always + * passes the following check. + */ + if (wasted > num_possible_cpus() / 3) + continue; + + /* and then don't consume more memory */ + if (allocs > last_allocs) + break; + last_allocs = allocs; + best_upa = upa; + } + *unit_sizep = alloc_size / best_upa; + + /* assign units to cpus accordingly */ + unit = 0; + for (group = 0; group_cnt[group]; group++) { + for_each_possible_cpu(cpu) + if (group_map[cpu] == group) + unit_map[cpu] = unit++; + unit = roundup(unit, best_upa); + } + + return unit; /* unit contains aligned number of units */ +} + +static bool __init pcpul_unit_to_cpu(int unit, const int *unit_map, + unsigned int *cpup); + +static void __init pcpul_lpage_dump_cfg(const char *lvl, size_t static_size, + size_t reserved_size, size_t dyn_size, + size_t unit_size, size_t lpage_size, + const int *unit_map, int nr_units) +{ + int width = 1, v = nr_units; + char empty_str[] = "--------"; + int upl, lpl; /* units per lpage, lpage per line */ + unsigned int cpu; + int lpage, unit; + + while (v /= 10) + width++; + empty_str[min_t(int, width, sizeof(empty_str) - 1)] = '\0'; + + upl = max_t(int, lpage_size / unit_size, 1); + lpl = rounddown_pow_of_two(max_t(int, 60 / (upl * (width + 1) + 2), 1)); + + printk("%spcpu-lpage: sta/res/dyn=%zu/%zu/%zu unit=%zu lpage=%zu", lvl, + static_size, reserved_size, dyn_size, unit_size, lpage_size); + + for (lpage = 0, unit = 0; unit < nr_units; unit++) { + if (!(unit % upl)) { + if (!(lpage++ % lpl)) { + printk("\n"); + printk("%spcpu-lpage: ", lvl); + } else + printk("| "); + } + if (pcpul_unit_to_cpu(unit, unit_map, &cpu)) + printk("%0*d ", width, cpu); + else + printk("%s ", empty_str); + } + printk("\n"); +} +#endif + /** * pcpu_setup_first_chunk - initialize the first percpu chunk * @static_size: the size of static percpu area in bytes @@ -1441,20 +1613,6 @@ static int __init percpu_alloc_setup(char *str) } early_param("percpu_alloc", percpu_alloc_setup); -static inline size_t pcpu_calc_fc_sizes(size_t static_size, - size_t reserved_size, - ssize_t *dyn_sizep) -{ - size_t size_sum; - - size_sum = PFN_ALIGN(static_size + reserved_size + - (*dyn_sizep >= 0 ? *dyn_sizep : 0)); - if (*dyn_sizep != 0) - *dyn_sizep = size_sum - static_size - reserved_size; - - return size_sum; -} - #if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \ !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) /** @@ -1637,122 +1795,6 @@ out_free_ar: #endif /* CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK */ #ifdef CONFIG_NEED_PER_CPU_LPAGE_FIRST_CHUNK -/** - * pcpu_lpage_build_unit_map - build unit_map for large page remapping - * @reserved_size: the size of reserved percpu area in bytes - * @dyn_sizep: in/out parameter for dynamic size, -1 for auto - * @unit_sizep: out parameter for unit size - * @unit_map: unit_map to be filled - * @cpu_distance_fn: callback to determine distance between cpus - * - * This function builds cpu -> unit map and determine other parameters - * considering needed percpu size, large page size and distances - * between CPUs in NUMA. - * - * CPUs which are of LOCAL_DISTANCE both ways are grouped together and - * may share units in the same large page. The returned configuration - * is guaranteed to have CPUs on different nodes on different large - * pages and >=75% usage of allocated virtual address space. - * - * RETURNS: - * On success, fills in @unit_map, sets *@dyn_sizep, *@unit_sizep and - * returns the number of units to be allocated. -errno on failure. - */ -int __init pcpu_lpage_build_unit_map(size_t reserved_size, ssize_t *dyn_sizep, - size_t *unit_sizep, size_t lpage_size, - int *unit_map, - pcpu_fc_cpu_distance_fn_t cpu_distance_fn) -{ - static int group_map[NR_CPUS] __initdata; - static int group_cnt[NR_CPUS] __initdata; - const size_t static_size = __per_cpu_end - __per_cpu_start; - int group_cnt_max = 0; - size_t size_sum, min_unit_size, alloc_size; - int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ - int last_allocs; - unsigned int cpu, tcpu; - int group, unit; - - /* - * Determine min_unit_size, alloc_size and max_upa such that - * alloc_size is multiple of lpage_size and is the smallest - * which can accomodate 4k aligned segments which are equal to - * or larger than min_unit_size. - */ - size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, dyn_sizep); - min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); - - alloc_size = roundup(min_unit_size, lpage_size); - upa = alloc_size / min_unit_size; - while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) - upa--; - max_upa = upa; - - /* group cpus according to their proximity */ - for_each_possible_cpu(cpu) { - group = 0; - next_group: - for_each_possible_cpu(tcpu) { - if (cpu == tcpu) - break; - if (group_map[tcpu] == group && - (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || - cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { - group++; - goto next_group; - } - } - group_map[cpu] = group; - group_cnt[group]++; - group_cnt_max = max(group_cnt_max, group_cnt[group]); - } - - /* - * Expand unit size until address space usage goes over 75% - * and then as much as possible without using more address - * space. - */ - last_allocs = INT_MAX; - for (upa = max_upa; upa; upa--) { - int allocs = 0, wasted = 0; - - if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) - continue; - - for (group = 0; group_cnt[group]; group++) { - int this_allocs = DIV_ROUND_UP(group_cnt[group], upa); - allocs += this_allocs; - wasted += this_allocs * upa - group_cnt[group]; - } - - /* - * Don't accept if wastage is over 25%. The - * greater-than comparison ensures upa==1 always - * passes the following check. - */ - if (wasted > num_possible_cpus() / 3) - continue; - - /* and then don't consume more memory */ - if (allocs > last_allocs) - break; - last_allocs = allocs; - best_upa = upa; - } - *unit_sizep = alloc_size / best_upa; - - /* assign units to cpus accordingly */ - unit = 0; - for (group = 0; group_cnt[group]; group++) { - for_each_possible_cpu(cpu) - if (group_map[cpu] == group) - unit_map[cpu] = unit++; - unit = roundup(unit, best_upa); - } - - return unit; /* unit contains aligned number of units */ -} - struct pcpul_ent { void *ptr; void *map_addr; @@ -1778,43 +1820,6 @@ static bool __init pcpul_unit_to_cpu(int unit, const int *unit_map, return false; } -static void __init pcpul_lpage_dump_cfg(const char *lvl, size_t static_size, - size_t reserved_size, size_t dyn_size, - size_t unit_size, size_t lpage_size, - const int *unit_map, int nr_units) -{ - int width = 1, v = nr_units; - char empty_str[] = "--------"; - int upl, lpl; /* units per lpage, lpage per line */ - unsigned int cpu; - int lpage, unit; - - while (v /= 10) - width++; - empty_str[min_t(int, width, sizeof(empty_str) - 1)] = '\0'; - - upl = max_t(int, lpage_size / unit_size, 1); - lpl = rounddown_pow_of_two(max_t(int, 60 / (upl * (width + 1) + 2), 1)); - - printk("%spcpu-lpage: sta/res/dyn=%zu/%zu/%zu unit=%zu lpage=%zu", lvl, - static_size, reserved_size, dyn_size, unit_size, lpage_size); - - for (lpage = 0, unit = 0; unit < nr_units; unit++) { - if (!(unit % upl)) { - if (!(lpage++ % lpl)) { - printk("\n"); - printk("%spcpu-lpage: ", lvl); - } else - printk("| "); - } - if (pcpul_unit_to_cpu(unit, unit_map, &cpu)) - printk("%0*d ", width, cpu); - else - printk("%s ", empty_str); - } - printk("\n"); -} - /** * pcpu_lpage_first_chunk - remap the first percpu chunk using large page * @reserved_size: the size of reserved percpu area in bytes |