include/linux/swap_slots.h

   1 #ifndef _LINUX_SWAP_SLOTS_H
   2 #define _LINUX_SWAP_SLOTS_H
   3
   4 #include <linux/swap.h>
   5 #include <linux/spinlock.h>
   6 #include <linux/mutex.h>
   7
   8 #define SWAP_SLOTS_CACHE_SIZE                   SWAP_BATCH
   9 #define THRESHOLD_ACTIVATE_SWAP_SLOTS_CACHE     (5*SWAP_SLOTS_CACHE_SIZE)
  10 #define THRESHOLD_DEACTIVATE_SWAP_SLOTS_CACHE   (2*SWAP_SLOTS_CACHE_SIZE)
  11
  12 struct swap_slots_cache {
  13         bool            lock_initialized;
  14         struct mutex    alloc_lock; /* protects slots, nr, cur */
  15         swp_entry_t     *slots;
  16         int             nr;
  17         int             cur;
  18         spinlock_t      free_lock;  /* protects slots_ret, n_ret */
  19         swp_entry_t     *slots_ret;
  20         int             n_ret;
  21 };
  22
  23 void disable_swap_slots_cache_lock(void);
  24 void reenable_swap_slots_cache_unlock(void);
  25 int enable_swap_slots_cache(void);
  26 int free_swap_slot(swp_entry_t entry);
  27
  28 extern bool swap_slot_cache_enabled;
  29
  30 #endif /* _LINUX_SWAP_SLOTS_H */