diff options
| -rw-r--r-- | mm/slab.c | 26 |
1 files changed, 15 insertions, 11 deletions
diff --git a/mm/slab.c b/mm/slab.c index 75127a6f1fd..a9ff4f7f986 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -3076,20 +3076,24 @@ ssize_t slabinfo_write(struct file *file, const char __user *buffer, } #endif +/** + * ksize - get the actual amount of memory allocated for a given object + * @objp: Pointer to the object + * + * kmalloc may internally round up allocations and return more memory + * than requested. ksize() can be used to determine the actual amount of + * memory allocated. The caller may use this additional memory, even though + * a smaller amount of memory was initially specified with the kmalloc call. + * The caller must guarantee that objp points to a valid object previously + * allocated with either kmalloc() or kmem_cache_alloc(). The object + * must not be freed during the duration of the call. + */ unsigned int ksize(const void *objp) { - kmem_cache_t *c; - unsigned long flags; - unsigned int size = 0; - - if (likely(objp != NULL)) { - local_irq_save(flags); - c = GET_PAGE_CACHE(virt_to_page(objp)); - size = kmem_cache_size(c); - local_irq_restore(flags); - } + if (unlikely(objp == NULL)) + return 0; - return size; + return obj_reallen(GET_PAGE_CACHE(virt_to_page(objp))); } |