diff options
Diffstat (limited to 'lib/cpumask.c')
| -rw-r--r-- | lib/cpumask.c | 215 |
1 files changed, 208 insertions, 7 deletions
diff --git a/lib/cpumask.c b/lib/cpumask.c index bb4f76d3c3e..b6513a9f289 100644 --- a/lib/cpumask.c +++ b/lib/cpumask.c @@ -1,7 +1,9 @@ +#include <linux/slab.h> #include <linux/kernel.h> #include <linux/bitops.h> #include <linux/cpumask.h> -#include <linux/module.h> +#include <linux/export.h> +#include <linux/bootmem.h> int __first_cpu(const cpumask_t *srcp) { @@ -15,14 +17,213 @@ int __next_cpu(int n, const cpumask_t *srcp) } EXPORT_SYMBOL(__next_cpu); -int __any_online_cpu(const cpumask_t *mask) +#if NR_CPUS > 64 +int __next_cpu_nr(int n, const cpumask_t *srcp) { - int cpu; + return min_t(int, nr_cpu_ids, + find_next_bit(srcp->bits, nr_cpu_ids, n+1)); +} +EXPORT_SYMBOL(__next_cpu_nr); +#endif - for_each_cpu_mask(cpu, *mask) { - if (cpu_online(cpu)) +/** + * cpumask_next_and - get the next cpu in *src1p & *src2p + * @n: the cpu prior to the place to search (ie. return will be > @n) + * @src1p: the first cpumask pointer + * @src2p: the second cpumask pointer + * + * Returns >= nr_cpu_ids if no further cpus set in both. + */ +int cpumask_next_and(int n, const struct cpumask *src1p, + const struct cpumask *src2p) +{ + while ((n = cpumask_next(n, src1p)) < nr_cpu_ids) + if (cpumask_test_cpu(n, src2p)) break; + return n; +} +EXPORT_SYMBOL(cpumask_next_and); + +/** + * cpumask_any_but - return a "random" in a cpumask, but not this one. + * @mask: the cpumask to search + * @cpu: the cpu to ignore. + * + * Often used to find any cpu but smp_processor_id() in a mask. + * Returns >= nr_cpu_ids if no cpus set. + */ +int cpumask_any_but(const struct cpumask *mask, unsigned int cpu) +{ + unsigned int i; + + cpumask_check(cpu); + for_each_cpu(i, mask) + if (i != cpu) + break; + return i; +} + +/* These are not inline because of header tangles. */ +#ifdef CONFIG_CPUMASK_OFFSTACK +/** + * alloc_cpumask_var_node - allocate a struct cpumask on a given node + * @mask: pointer to cpumask_var_t where the cpumask is returned + * @flags: GFP_ flags + * + * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is + * a nop returning a constant 1 (in <linux/cpumask.h>) + * Returns TRUE if memory allocation succeeded, FALSE otherwise. + * + * In addition, mask will be NULL if this fails. Note that gcc is + * usually smart enough to know that mask can never be NULL if + * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case + * too. + */ +bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) +{ + *mask = kmalloc_node(cpumask_size(), flags, node); + +#ifdef CONFIG_DEBUG_PER_CPU_MAPS + if (!*mask) { + printk(KERN_ERR "=> alloc_cpumask_var: failed!\n"); + dump_stack(); + } +#endif + /* FIXME: Bandaid to save us from old primitives which go to NR_CPUS. */ + if (*mask) { + unsigned char *ptr = (unsigned char *)cpumask_bits(*mask); + unsigned int tail; + tail = BITS_TO_LONGS(NR_CPUS - nr_cpumask_bits) * sizeof(long); + memset(ptr + cpumask_size() - tail, 0, tail); } - return cpu; + + return *mask != NULL; +} +EXPORT_SYMBOL(alloc_cpumask_var_node); + +bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node) +{ + return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node); +} +EXPORT_SYMBOL(zalloc_cpumask_var_node); + +/** + * alloc_cpumask_var - allocate a struct cpumask + * @mask: pointer to cpumask_var_t where the cpumask is returned + * @flags: GFP_ flags + * + * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is + * a nop returning a constant 1 (in <linux/cpumask.h>). + * + * See alloc_cpumask_var_node. + */ +bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) +{ + return alloc_cpumask_var_node(mask, flags, NUMA_NO_NODE); +} +EXPORT_SYMBOL(alloc_cpumask_var); + +bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) +{ + return alloc_cpumask_var(mask, flags | __GFP_ZERO); +} +EXPORT_SYMBOL(zalloc_cpumask_var); + +/** + * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena. + * @mask: pointer to cpumask_var_t where the cpumask is returned + * + * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is + * a nop (in <linux/cpumask.h>). + * Either returns an allocated (zero-filled) cpumask, or causes the + * system to panic. + */ +void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask) +{ + *mask = memblock_virt_alloc(cpumask_size(), 0); +} + +/** + * free_cpumask_var - frees memory allocated for a struct cpumask. + * @mask: cpumask to free + * + * This is safe on a NULL mask. + */ +void free_cpumask_var(cpumask_var_t mask) +{ + kfree(mask); +} +EXPORT_SYMBOL(free_cpumask_var); + +/** + * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var + * @mask: cpumask to free + */ +void __init free_bootmem_cpumask_var(cpumask_var_t mask) +{ + memblock_free_early(__pa(mask), cpumask_size()); +} +#endif + +/** + * cpumask_set_cpu_local_first - set i'th cpu with local numa cpu's first + * + * @i: index number + * @numa_node: local numa_node + * @dstp: cpumask with the relevant cpu bit set according to the policy + * + * This function sets the cpumask according to a numa aware policy. + * cpumask could be used as an affinity hint for the IRQ related to a + * queue. When the policy is to spread queues across cores - local cores + * first. + * + * Returns 0 on success, -ENOMEM for no memory, and -EAGAIN when failed to set + * the cpu bit and need to re-call the function. + */ +int cpumask_set_cpu_local_first(int i, int numa_node, cpumask_t *dstp) +{ + cpumask_var_t mask; + int cpu; + int ret = 0; + + if (!zalloc_cpumask_var(&mask, GFP_KERNEL)) + return -ENOMEM; + + i %= num_online_cpus(); + + if (numa_node == -1 || !cpumask_of_node(numa_node)) { + /* Use all online cpu's for non numa aware system */ + cpumask_copy(mask, cpu_online_mask); + } else { + int n; + + cpumask_and(mask, + cpumask_of_node(numa_node), cpu_online_mask); + + n = cpumask_weight(mask); + if (i >= n) { + i -= n; + + /* If index > number of local cpu's, mask out local + * cpu's + */ + cpumask_andnot(mask, cpu_online_mask, mask); + } + } + + for_each_cpu(cpu, mask) { + if (--i < 0) + goto out; + } + + ret = -EAGAIN; + +out: + free_cpumask_var(mask); + + if (!ret) + cpumask_set_cpu(cpu, dstp); + + return ret; } -EXPORT_SYMBOL(__any_online_cpu); +EXPORT_SYMBOL(cpumask_set_cpu_local_first); |
