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Linux kernel mirror (for testing)
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_ZSWAP_H
3#define _LINUX_ZSWAP_H
4
5#include <linux/types.h>
6#include <linux/mm_types.h>
7
8struct lruvec;
9
10extern atomic_t zswap_stored_pages;
11
12#ifdef CONFIG_ZSWAP
13
14struct zswap_lruvec_state {
15 /*
16 * Number of pages in zswap that should be protected from the shrinker.
17 * This number is an estimate of the following counts:
18 *
19 * a) Recent page faults.
20 * b) Recent insertion to the zswap LRU. This includes new zswap stores,
21 * as well as recent zswap LRU rotations.
22 *
23 * These pages are likely to be warm, and might incur IO if the are written
24 * to swap.
25 */
26 atomic_long_t nr_zswap_protected;
27};
28
29unsigned long zswap_total_pages(void);
30bool zswap_store(struct folio *folio);
31bool zswap_load(struct folio *folio);
32void zswap_invalidate(swp_entry_t swp);
33int zswap_swapon(int type, unsigned long nr_pages);
34void zswap_swapoff(int type);
35void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg);
36void zswap_lruvec_state_init(struct lruvec *lruvec);
37void zswap_folio_swapin(struct folio *folio);
38bool zswap_is_enabled(void);
39bool zswap_never_enabled(void);
40#else
41
42struct zswap_lruvec_state {};
43
44static inline bool zswap_store(struct folio *folio)
45{
46 return false;
47}
48
49static inline bool zswap_load(struct folio *folio)
50{
51 return false;
52}
53
54static inline void zswap_invalidate(swp_entry_t swp) {}
55static inline int zswap_swapon(int type, unsigned long nr_pages)
56{
57 return 0;
58}
59static inline void zswap_swapoff(int type) {}
60static inline void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg) {}
61static inline void zswap_lruvec_state_init(struct lruvec *lruvec) {}
62static inline void zswap_folio_swapin(struct folio *folio) {}
63
64static inline bool zswap_is_enabled(void)
65{
66 return false;
67}
68
69static inline bool zswap_never_enabled(void)
70{
71 return true;
72}
73
74#endif
75
76#endif /* _LINUX_ZSWAP_H */