1/*
2 * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 *
28 */
29/*-
30 * Copyright (c) 1999,2000,2001 Jonathan Lemon <jlemon@FreeBSD.org>
31 * All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 *    notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 *    notice, this list of conditions and the following disclaimer in the
40 *    documentation and/or other materials provided with the distribution.
41 *
42 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
43 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
44 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
45 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
46 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
47 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
48 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
49 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
50 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
51 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * SUCH DAMAGE.
53 */
54
55#include <sys/kern_event.h>
56#include <sys/kern_memorystatus.h>
57
58#include <kern/sched_prim.h>
59#include <kern/task.h>
60#include <kern/thread.h>
61#include <libkern/libkern.h>
62#include <sys/sysctl.h>
63
64extern unsigned int    vm_page_free_count;
65extern unsigned int    vm_page_active_count;
66extern unsigned int    vm_page_inactive_count;
67extern unsigned int    vm_page_purgeable_count;
68extern unsigned int    vm_page_wire_count;
69
70static void kern_memorystatus_thread(void);
71
72int kern_memorystatus_wakeup = 0;
73int kern_memorystatus_level = 0;
74int kern_memorystatus_last_level = 0;
75unsigned int kern_memorystatus_kev_failure_count = 0;
76
77SYSCTL_INT(_kern, OID_AUTO, memorystatus_level, CTLFLAG_RD, &kern_memorystatus_level, 0, "");
78SYSCTL_UINT(_kern, OID_AUTO, memorystatus_kev_failure_count, CTLFLAG_RD, &kern_memorystatus_kev_failure_count, 0, "");
79
80__private_extern__ void
81kern_memorystatus_init(void)
82{
83	(void)kernel_thread(kernel_task, kern_memorystatus_thread);
84}
85
86static void
87kern_memorystatus_thread(void)
88{
89	struct kev_msg ev_msg;
90	struct {
91		uint32_t free_pages;
92		uint32_t active_pages;
93		uint32_t inactive_pages;
94		uint32_t purgeable_pages;
95		uint32_t wired_pages;
96	} data;
97	int ret;
98
99	while(1) {
100
101		kern_memorystatus_last_level = kern_memorystatus_level;
102
103		ev_msg.vendor_code    = KEV_VENDOR_APPLE;
104		ev_msg.kev_class      = KEV_SYSTEM_CLASS;
105		ev_msg.kev_subclass   = KEV_MEMORYSTATUS_SUBCLASS;
106
107		/* pass the memory status level in the event code (as percent used) */
108		ev_msg.event_code     = 100 - kern_memorystatus_last_level;
109
110		ev_msg.dv[0].data_length = sizeof data;
111		ev_msg.dv[0].data_ptr = &data;
112		ev_msg.dv[1].data_length = 0;
113
114		data.free_pages = vm_page_free_count;
115		data.active_pages = vm_page_active_count;
116		data.inactive_pages = vm_page_inactive_count;
117		data.purgeable_pages = vm_page_purgeable_count;
118		data.wired_pages = vm_page_wire_count;
119
120		ret = kev_post_msg(&ev_msg);
121		if (ret) {
122			kern_memorystatus_kev_failure_count++;
123			printf("%s: kev_post_msg() failed, err %d\n", __func__, ret);
124		}
125
126		if (kern_memorystatus_level >= kern_memorystatus_last_level + 5 ||
127		    kern_memorystatus_level <= kern_memorystatus_last_level - 5)
128			continue;
129
130		assert_wait(&kern_memorystatus_wakeup, THREAD_UNINT);
131		(void)thread_block((thread_continue_t)kern_memorystatus_thread);
132	}
133}
134