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 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 } __packed;
67 
68 
69 /*
70  * appldata_get_mem_data()
71  *
72  * gather memory data
73  */
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 	.owner     = THIS_MODULE,
122 	.mod_lvl   = {0xF0, 0xF0},		/* EBCDIC "00" */
123 };
124 
125 
126 /*
127  * appldata_mem_init()
128  *
129  * init_data, register ops
130  */
131 static int __init appldata_mem_init(void)
132 {
133 	int ret;
134 
135 	ops.data = kzalloc(sizeof(struct appldata_mem_data), GFP_KERNEL);
136 	if (!ops.data)
137 		return -ENOMEM;
138 
139 	ret = appldata_register_ops(&ops);
140 	if (ret)
141 		kfree(ops.data);
142 
143 	return ret;
144 }
145 
146 /*
147  * appldata_mem_exit()
148  *
149  * unregister ops
150  */
151 static void __exit appldata_mem_exit(void)
152 {
153 	appldata_unregister_ops(&ops);
154 	kfree(ops.data);
155 }
156 
157 
158 module_init(appldata_mem_init);
159 module_exit(appldata_mem_exit);
160 
161 MODULE_LICENSE("GPL");
162 MODULE_AUTHOR("Gerald Schaefer");
163 MODULE_DESCRIPTION("Linux-VM Monitor Stream, MEMORY statistics");
164