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 */
33 struct 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 */
72 static 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
114 static 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 */
129 static 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 */
149 static void __exit appldata_mem_exit(void)
150 {
151 appldata_unregister_ops(&ops);
152 kfree(ops.data);
153 }
154
155
156 module_init(appldata_mem_init);
157 module_exit(appldata_mem_exit);
158
159 MODULE_LICENSE("GPL");
160 MODULE_AUTHOR("Gerald Schaefer");
161 MODULE_DESCRIPTION("Linux-VM Monitor Stream, MEMORY statistics");
162
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