linux-mem.h revision 4f6cc9ab5337879c4a79564b3aed4fa429d1cd12 
1/*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26/*
27 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 *
30 * Copyright (c) 2011, 2012, Intel Corporation.
31 */
32/*
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
35 *
36 * libcfs/include/libcfs/linux/linux-mem.h
37 *
38 * Basic library routines.
39 */
40
41#ifndef __LIBCFS_LINUX_CFS_MEM_H__
42#define __LIBCFS_LINUX_CFS_MEM_H__
43
44#ifndef __LIBCFS_LIBCFS_H__
45#error Do not #include this file directly. #include <linux/libcfs/libcfs.h> instead
46#endif
47
48
49#include <linux/mm.h>
50#include <linux/vmalloc.h>
51#include <linux/pagemap.h>
52#include <linux/slab.h>
53#include <linux/memcontrol.h>
54#include <linux/mm_inline.h>
55
56#define CFS_PAGE_MASK		   (~((__u64)PAGE_CACHE_SIZE-1))
57#define page_index(p)       ((p)->index)
58
59#define memory_pressure_get() (current->flags & PF_MEMALLOC)
60#define memory_pressure_set() do { current->flags |= PF_MEMALLOC; } while (0)
61#define memory_pressure_clr() do { current->flags &= ~PF_MEMALLOC; } while (0)
62
63#if BITS_PER_LONG == 32
64/* limit to lowmem on 32-bit systems */
65#define NUM_CACHEPAGES \
66	min(totalram_pages, 1UL << (30 - PAGE_CACHE_SHIFT) * 3 / 4)
67#else
68#define NUM_CACHEPAGES totalram_pages
69#endif
70
71/*
72 * In Linux there is no way to determine whether current execution context is
73 * blockable.
74 */
75#define ALLOC_ATOMIC_TRY   GFP_ATOMIC
76
77#define DECL_MMSPACE		mm_segment_t __oldfs
78#define MMSPACE_OPEN \
79	do { __oldfs = get_fs(); set_fs(get_ds());} while(0)
80#define MMSPACE_CLOSE	       set_fs(__oldfs)
81
82/*
83 * Shrinker
84 */
85
86# define SHRINKER_ARGS(sc, nr_to_scan, gfp_mask)  \
87		       struct shrinker *shrinker, \
88		       struct shrink_control *sc
89# define shrink_param(sc, var) ((sc)->var)
90
91typedef int (*shrinker_t)(SHRINKER_ARGS(sc, nr_to_scan, gfp_mask));
92
93static inline
94struct shrinker *set_shrinker(int seek, shrinker_t func)
95{
96	struct shrinker *s;
97
98	s = kmalloc(sizeof(*s), GFP_KERNEL);
99	if (s == NULL)
100		return (NULL);
101
102	s->shrink = func;
103	s->seeks = seek;
104
105	register_shrinker(s);
106
107	return s;
108}
109
110static inline
111void remove_shrinker(struct shrinker *shrinker)
112{
113	if (shrinker == NULL)
114		return;
115
116	unregister_shrinker(shrinker);
117	kfree(shrinker);
118}
119
120#endif /* __LINUX_CFS_MEM_H__ */
121