1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Data gathering module for Linux-VM Monitor Stream, Stage 1.
4 * Collects data related to memory management.
5 *
6 * Copyright IBM Corp. 2003, 2006
7 *
8 * Author: Gerald Schaefer <gerald.schaefer@de.ibm.com>
9 */
10
11#include <linux/module.h>
12#include <linux/init.h>
13#include <linux/errno.h>
14#include <linux/kernel_stat.h>
15#include <linux/pagemap.h>
16#include <linux/swap.h>
17#include <linux/slab.h>
18#include <linux/io.h>
19
20#include "appldata.h"
21
22
23#define P2K(x) ((x) << (PAGE_SHIFT - 10))	/* Converts #Pages to KB */
24
25/*
26 * Memory data
27 *
28 * This is accessed as binary data by z/VM. If changes to it can't be avoided,
29 * the structure version (product ID, see appldata_base.c) needs to be changed
30 * as well and all documentation and z/VM applications using it must be
31 * updated.
32 */
33struct appldata_mem_data {
34	u64 timestamp;
35	u32 sync_count_1;       /* after VM collected the record data, */
36	u32 sync_count_2;	/* sync_count_1 and sync_count_2 should be the
37				   same. If not, the record has been updated on
38				   the Linux side while VM was collecting the
39				   (possibly corrupt) data */
40
41	u64 pgpgin;		/* data read from disk  */
42	u64 pgpgout;		/* data written to disk */
43	u64 pswpin;		/* pages swapped in  */
44	u64 pswpout;		/* pages swapped out */
45
46	u64 sharedram;		/* sharedram is currently set to 0 */
47
48	u64 totalram;		/* total main memory size */
49	u64 freeram;		/* free main memory size  */
50	u64 totalhigh;		/* total high memory size */
51	u64 freehigh;		/* free high memory size  */
52
53	u64 bufferram;		/* memory reserved for buffers, free cache */
54	u64 cached;		/* size of (used) cache, w/o buffers */
55	u64 totalswap;		/* total swap space size */
56	u64 freeswap;		/* free swap space */
57
58// New in 2.6 -->
59	u64 pgalloc;		/* page allocations */
60	u64 pgfault;		/* page faults (major+minor) */
61	u64 pgmajfault;		/* page faults (major only) */
62// <-- New in 2.6
63
64} __packed;
65
66
67/*
68 * appldata_get_mem_data()
69 *
70 * gather memory data
71 */
72static void appldata_get_mem_data(void *data)
73{
74	/*
75	 * don't put large structures on the stack, we are
76	 * serialized through the appldata_ops_mutex and can use static
77	 */
78	static struct sysinfo val;
79	unsigned long ev[NR_VM_EVENT_ITEMS];
80	struct appldata_mem_data *mem_data;
81
82	mem_data = data;
83	mem_data->sync_count_1++;
84
85	all_vm_events(ev);
86	mem_data->pgpgin     = ev[PGPGIN] >> 1;
87	mem_data->pgpgout    = ev[PGPGOUT] >> 1;
88	mem_data->pswpin     = ev[PSWPIN];
89	mem_data->pswpout    = ev[PSWPOUT];
90	mem_data->pgalloc    = ev[PGALLOC_NORMAL];
91	mem_data->pgalloc    += ev[PGALLOC_DMA];
92	mem_data->pgfault    = ev[PGFAULT];
93	mem_data->pgmajfault = ev[PGMAJFAULT];
94
95	si_meminfo(&val);
96	mem_data->sharedram = val.sharedram;
97	mem_data->totalram  = P2K(val.totalram);
98	mem_data->freeram   = P2K(val.freeram);
99	mem_data->totalhigh = P2K(val.totalhigh);
100	mem_data->freehigh  = P2K(val.freehigh);
101	mem_data->bufferram = P2K(val.bufferram);
102	mem_data->cached    = P2K(global_node_page_state(NR_FILE_PAGES)
103				- val.bufferram);
104
105	si_swapinfo(&val);
106	mem_data->totalswap = P2K(val.totalswap);
107	mem_data->freeswap  = P2K(val.freeswap);
108
109	mem_data->timestamp = get_tod_clock();
110	mem_data->sync_count_2++;
111}
112
113
114static struct appldata_ops ops = {
115	.name      = "mem",
116	.record_nr = APPLDATA_RECORD_MEM_ID,
117	.size	   = sizeof(struct appldata_mem_data),
118	.callback  = &appldata_get_mem_data,
119	.owner     = THIS_MODULE,
120	.mod_lvl   = {0xF0, 0xF0},		/* EBCDIC "00" */
121};
122
123
124/*
125 * appldata_mem_init()
126 *
127 * init_data, register ops
128 */
129static int __init appldata_mem_init(void)
130{
131	int ret;
132
133	ops.data = kzalloc(sizeof(struct appldata_mem_data), GFP_KERNEL);
134	if (!ops.data)
135		return -ENOMEM;
136
137	ret = appldata_register_ops(&ops);
138	if (ret)
139		kfree(ops.data);
140
141	return ret;
142}
143
144/*
145 * appldata_mem_exit()
146 *
147 * unregister ops
148 */
149static void __exit appldata_mem_exit(void)
150{
151	appldata_unregister_ops(&ops);
152	kfree(ops.data);
153}
154
155
156module_init(appldata_mem_init);
157module_exit(appldata_mem_exit);
158
159MODULE_LICENSE("GPL");
160MODULE_AUTHOR("Gerald Schaefer");
161MODULE_DESCRIPTION("Linux-VM Monitor Stream, MEMORY statistics");
162