LXR linux/include/linux/swap

   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
  13struct 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
  24void disable_swap_slots_cache_lock(void);
  25void reenable_swap_slots_cache_unlock(void);
  26int enable_swap_slots_cache(void);
  27int free_swap_slot(swp_entry_t entry);
  28
  29extern bool swap_slot_cache_enabled;
  30
  31#endif /* _LINUX_SWAP_SLOTS_H */
  32