xref: /freebsd/sys/compat/linuxkpi/common/include/linux/shrinker.h (revision 6be3386466ab79a84b48429ae66244f21526d3df)
1 /*-
2  * Copyright (c) 2020 Emmanuel Vadot <manu@FreeBSD.org>
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  * $FreeBSD$
26  */
27 
28 #ifndef __LINUX_SHRINKER_H__
29 #define	__LINUX_SHRINKER_H__
30 
31 #include <sys/queue.h>
32 
33 struct shrink_control {
34 	unsigned long	nr_to_scan;
35 	unsigned long	nr_scanned;
36 };
37 
38 struct shrinker {
39 	unsigned long		(*count_objects)(struct shrinker *, struct shrink_control *);
40 	unsigned long		(*scan_objects)(struct shrinker *, struct shrink_control *);
41 	int			seeks;
42 	long			batch;
43 	TAILQ_ENTRY(shrinker)	next;
44 };
45 
46 #define	SHRINK_STOP	(~0UL)
47 
48 #define	DEFAULT_SEEKS	2
49 
50 int	linuxkpi_register_shrinker(struct shrinker *s);
51 void	linuxkpi_unregister_shrinker(struct shrinker *s);
52 
53 #define	register_shrinker(s)	linuxkpi_register_shrinker(s)
54 #define	unregister_shrinker(s)	linuxkpi_unregister_shrinker(s)
55 
56 #endif	/* __LINUX_SHRINKER_H__ */
57