io_uring/alloc_cache.h

   1 #ifndef IOU_ALLOC_CACHE_H
   2 #define IOU_ALLOC_CACHE_H
   3
   4 /*
   5  * Don't allow the cache to grow beyond this size.
   6  */
   7 #define IO_ALLOC_CACHE_MAX      512
   8
   9 struct io_cache_entry {
  10         struct io_wq_work_node node;
  11 };
  12
  13 static inline bool io_alloc_cache_put(struct io_alloc_cache *cache,
  14                                       struct io_cache_entry *entry)
  15 {
  16         if (cache->nr_cached < cache->max_cached) {
  17                 cache->nr_cached++;
  18                 wq_stack_add_head(&entry->node, &cache->list);
  19                 /* KASAN poisons object */
  20                 kasan_slab_free_mempool(entry);
  21                 return true;
  22         }
  23         return false;
  24 }
  25
  26 static inline bool io_alloc_cache_empty(struct io_alloc_cache *cache)
  27 {
  28         return !cache->list.next;
  29 }
  30
  31 static inline struct io_cache_entry *io_alloc_cache_get(struct io_alloc_cache *cache)
  32 {
  33         if (cache->list.next) {
  34                 struct io_cache_entry *entry;
  35
  36                 entry = container_of(cache->list.next, struct io_cache_entry, node);
  37                 kasan_unpoison_range(entry, cache->elem_size);
  38                 cache->list.next = cache->list.next->next;
  39                 cache->nr_cached--;
  40                 return entry;
  41         }
  42
  43         return NULL;
  44 }
  45
  46 static inline void io_alloc_cache_init(struct io_alloc_cache *cache,
  47                                        unsigned max_nr, size_t size)
  48 {
  49         cache->list.next = NULL;
  50         cache->nr_cached = 0;
  51         cache->max_cached = max_nr;
  52         cache->elem_size = size;
  53 }
  54
  55 static inline void io_alloc_cache_free(struct io_alloc_cache *cache,
  56                                         void (*free)(struct io_cache_entry *))
  57 {
  58         while (1) {
  59                 struct io_cache_entry *entry = io_alloc_cache_get(cache);
  60
  61                 if (!entry)
  62                         break;
  63                 free(entry);
  64         }
  65         cache->nr_cached = 0;
  66 }
  67 #endif