include/linux/swap_slots.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_SWAP_SLOTS_H
   3 #define _LINUX_SWAP_SLOTS_H
   4
   5 #include <linux/swap.h>
   6 #include <linux/spinlock.h>
   7 #include <linux/mutex.h>
   8
   9 #define SWAP_SLOTS_CACHE_SIZE                   SWAP_BATCH
  10 #define THRESHOLD_ACTIVATE_SWAP_SLOTS_CACHE     (5*SWAP_SLOTS_CACHE_SIZE)
  11 #define THRESHOLD_DEACTIVATE_SWAP_SLOTS_CACHE   (2*SWAP_SLOTS_CACHE_SIZE)
  12
  13 struct swap_slots_cache {
  14         bool            lock_initialized;
  15         struct mutex    alloc_lock; /* protects slots, nr, cur */
  16         swp_entry_t     *slots;
  17         int             nr;
  18         int             cur;
  19         spinlock_t      free_lock;  /* protects slots_ret, n_ret */
  20         swp_entry_t     *slots_ret;
  21         int             n_ret;
  22 };
  23
  24 void disable_swap_slots_cache_lock(void);
  25 void reenable_swap_slots_cache_unlock(void);
  26 int enable_swap_slots_cache(void);
  27 int free_swap_slot(swp_entry_t entry);
  28
  29 extern bool swap_slot_cache_enabled;
  30
  31 #endif /* _LINUX_SWAP_SLOTS_H */