1 /*
2 * Data gathering module for Linux-VM Monitor Stream, Stage 1.
3 * Collects data related to memory management.
4 *
5 * Copyright IBM Corp. 2003, 2006
6 *
7 * Author: Gerald Schaefer <gerald.schaefer@de.ibm.com>
8 */
9
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/errno.h>
13 #include <linux/kernel_stat.h>
14 #include <linux/pagemap.h>
15 #include <linux/swap.h>
16 #include <asm/io.h>
17
18 #include "appldata.h"
19
20
21 #define P2K(x) ((x) << (PAGE_SHIFT - 10)) /* Converts #Pages to KB */
22
23 /*
24 * Memory data
25 *
26 * This is accessed as binary data by z/VM. If changes to it can't be avoided,
27 * the structure version (product ID, see appldata_base.c) needs to be changed
28 * as well and all documentation and z/VM applications using it must be
29 * updated.
30 *
31 * The record layout is documented in the Linux for zSeries Device Drivers
32 * book:
33 * http://oss.software.ibm.com/developerworks/opensource/linux390/index.shtml
34 */
35 static struct appldata_mem_data {
36 u64 timestamp;
37 u32 sync_count_1; /* after VM collected the record data, */
38 u32 sync_count_2; /* sync_count_1 and sync_count_2 should be the
39 same. If not, the record has been updated on
40 the Linux side while VM was collecting the
41 (possibly corrupt) data */
42
43 u64 pgpgin; /* data read from disk */
44 u64 pgpgout; /* data written to disk */
45 u64 pswpin; /* pages swapped in */
46 u64 pswpout; /* pages swapped out */
47
48 u64 sharedram; /* sharedram is currently set to 0 */
49
50 u64 totalram; /* total main memory size */
51 u64 freeram; /* free main memory size */
52 u64 totalhigh; /* total high memory size */
53 u64 freehigh; /* free high memory size */
54
55 u64 bufferram; /* memory reserved for buffers, free cache */
56 u64 cached; /* size of (used) cache, w/o buffers */
57 u64 totalswap; /* total swap space size */
58 u64 freeswap; /* free swap space */
59
60 // New in 2.6 -->
61 u64 pgalloc; /* page allocations */
62 u64 pgfault; /* page faults (major+minor) */
63 u64 pgmajfault; /* page faults (major only) */
64 // <-- New in 2.6
65
66 } __attribute__((packed)) appldata_mem_data;
67
68
69 /*
70 * appldata_get_mem_data()
71 *
72 * gather memory data
73 */
appldata_get_mem_data(void * data)74 static void appldata_get_mem_data(void *data)
75 {
76 /*
77 * don't put large structures on the stack, we are
78 * serialized through the appldata_ops_mutex and can use static
79 */
80 static struct sysinfo val;
81 unsigned long ev[NR_VM_EVENT_ITEMS];
82 struct appldata_mem_data *mem_data;
83
84 mem_data = data;
85 mem_data->sync_count_1++;
86
87 all_vm_events(ev);
88 mem_data->pgpgin = ev[PGPGIN] >> 1;
89 mem_data->pgpgout = ev[PGPGOUT] >> 1;
90 mem_data->pswpin = ev[PSWPIN];
91 mem_data->pswpout = ev[PSWPOUT];
92 mem_data->pgalloc = ev[PGALLOC_NORMAL];
93 mem_data->pgalloc += ev[PGALLOC_DMA];
94 mem_data->pgfault = ev[PGFAULT];
95 mem_data->pgmajfault = ev[PGMAJFAULT];
96
97 si_meminfo(&val);
98 mem_data->sharedram = val.sharedram;
99 mem_data->totalram = P2K(val.totalram);
100 mem_data->freeram = P2K(val.freeram);
101 mem_data->totalhigh = P2K(val.totalhigh);
102 mem_data->freehigh = P2K(val.freehigh);
103 mem_data->bufferram = P2K(val.bufferram);
104 mem_data->cached = P2K(global_page_state(NR_FILE_PAGES)
105 - val.bufferram);
106
107 si_swapinfo(&val);
108 mem_data->totalswap = P2K(val.totalswap);
109 mem_data->freeswap = P2K(val.freeswap);
110
111 mem_data->timestamp = get_tod_clock();
112 mem_data->sync_count_2++;
113 }
114
115
116 static struct appldata_ops ops = {
117 .name = "mem",
118 .record_nr = APPLDATA_RECORD_MEM_ID,
119 .size = sizeof(struct appldata_mem_data),
120 .callback = &appldata_get_mem_data,
121 .data = &appldata_mem_data,
122 .owner = THIS_MODULE,
123 .mod_lvl = {0xF0, 0xF0}, /* EBCDIC "00" */
124 };
125
126
127 /*
128 * appldata_mem_init()
129 *
130 * init_data, register ops
131 */
appldata_mem_init(void)132 static int __init appldata_mem_init(void)
133 {
134 return appldata_register_ops(&ops);
135 }
136
137 /*
138 * appldata_mem_exit()
139 *
140 * unregister ops
141 */
appldata_mem_exit(void)142 static void __exit appldata_mem_exit(void)
143 {
144 appldata_unregister_ops(&ops);
145 }
146
147
148 module_init(appldata_mem_init);
149 module_exit(appldata_mem_exit);
150
151 MODULE_LICENSE("GPL");
152 MODULE_AUTHOR("Gerald Schaefer");
153 MODULE_DESCRIPTION("Linux-VM Monitor Stream, MEMORY statistics");
154