X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=sidebyside;f=mm%2Fslab.c;h=a9ff4f7f9860b2f1f37891fe4fe8c50a5caa637d;hb=3b30bbd963ac2606b0377b39c9d148d6eeef7dce;hp=ae6cca04de4bc7cdbf0d3586ae3af12f12dd0808;hpb=0abf40c1ac3f25d264c019e1cfe155d590defb87;p=linux-2.6 diff --git a/mm/slab.c b/mm/slab.c index ae6cca04de..a9ff4f7f98 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -189,6 +189,7 @@ * is less than 512 (PAGE_SIZE<<3), but greater than 256. */ +typedef unsigned int kmem_bufctl_t; #define BUFCTL_END (((kmem_bufctl_t)(~0U))-0) #define BUFCTL_FREE (((kmem_bufctl_t)(~0U))-1) #define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-2) @@ -2165,7 +2166,9 @@ static inline void *__cache_alloc(kmem_cache_t *cachep, unsigned int __nocast fl objp = cache_alloc_refill(cachep, flags); } local_irq_restore(save_flags); - objp = cache_alloc_debugcheck_after(cachep, flags, objp, __builtin_return_address(0)); + objp = cache_alloc_debugcheck_after(cachep, flags, objp, + __builtin_return_address(0)); + prefetchw(objp); return objp; } @@ -3073,20 +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))); }