diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig | 7 | ||||
| -rw-r--r-- | lib/cpumask.c | 54 |
2 files changed, 58 insertions, 3 deletions
diff --git a/lib/Kconfig b/lib/Kconfig index fd4118e097f..2ba43c4a5b0 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -159,4 +159,11 @@ config CHECK_SIGNATURE config HAVE_LMB boolean +config CPUMASK_OFFSTACK + bool "Force CPU masks off stack" if DEBUG_PER_CPU_MAPS + help + Use dynamic allocation for cpumask_var_t, instead of putting + them on the stack. This is a bit more expensive, but avoids + stack overflow. + endmenu diff --git a/lib/cpumask.c b/lib/cpumask.c index 8d03f22c6ce..a24edf137f4 100644 --- a/lib/cpumask.c +++ b/lib/cpumask.c @@ -76,15 +76,28 @@ int cpumask_any_but(const struct cpumask *mask, unsigned int cpu) /* These are not inline because of header tangles. */ #ifdef CONFIG_CPUMASK_OFFSTACK -bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) +/** + * 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) { if (likely(slab_is_available())) - *mask = kmalloc(cpumask_size(), flags); + *mask = kmalloc_node(cpumask_size(), flags, node); else { #ifdef CONFIG_DEBUG_PER_CPU_MAPS printk(KERN_ERR "=> alloc_cpumask_var: kmalloc not available!\n"); - dump_stack(); #endif *mask = NULL; } @@ -96,19 +109,54 @@ bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags) #endif return *mask != NULL; } +EXPORT_SYMBOL(alloc_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_node_id()); +} EXPORT_SYMBOL(alloc_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 returning a constant 1 (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 = alloc_bootmem(cpumask_size()); } +/** + * 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) { free_bootmem((unsigned long)mask, cpumask_size()); |