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 <linux/slab.h>
17 #include <asm/io.h>
18 
19 #include "appldata.h"
20 
21 
22 #define P2K(x) ((x) << (PAGE_SHIFT - 10))	/* Converts #Pages to KB */
23 
24 /*
25  * Memory data
26  *
27  * This is accessed as binary data by z/VM. If changes to it can't be avoided,
28  * the structure version (product ID, see appldata_base.c) needs to be changed
29  * as well and all documentation and z/VM applications using it must be
30  * updated.
31  *
32  * The record layout is documented in the Linux for zSeries Device Drivers
33  * book:
34  * http://oss.software.ibm.com/developerworks/opensource/linux390/index.shtml
35  */
36 struct appldata_mem_data {
37 	u64 timestamp;
38 	u32 sync_count_1;       /* after VM collected the record data, */
39 	u32 sync_count_2;	/* sync_count_1 and sync_count_2 should be the
40 				   same. If not, the record has been updated on
41 				   the Linux side while VM was collecting the
42 				   (possibly corrupt) data */
43 
44 	u64 pgpgin;		/* data read from disk  */
45 	u64 pgpgout;		/* data written to disk */
46 	u64 pswpin;		/* pages swapped in  */
47 	u64 pswpout;		/* pages swapped out */
48 
49 	u64 sharedram;		/* sharedram is currently set to 0 */
50 
51 	u64 totalram;		/* total main memory size */
52 	u64 freeram;		/* free main memory size  */
53 	u64 totalhigh;		/* total high memory size */
54 	u64 freehigh;		/* free high memory size  */
55 
56 	u64 bufferram;		/* memory reserved for buffers, free cache */
57 	u64 cached;		/* size of (used) cache, w/o buffers */
58 	u64 totalswap;		/* total swap space size */
59 	u64 freeswap;		/* free swap space */
60 
61 // New in 2.6 -->
62 	u64 pgalloc;		/* page allocations */
63 	u64 pgfault;		/* page faults (major+minor) */
64 	u64 pgmajfault;		/* page faults (major only) */
65 // <-- New in 2.6
66 
67 } __packed;
68 
69 
70 /*
71  * appldata_get_mem_data()
72  *
73  * gather memory data
74  */
75 static void appldata_get_mem_data(void *data)
76 {
77 	/*
78 	 * don't put large structures on the stack, we are
79 	 * serialized through the appldata_ops_mutex and can use static
80 	 */
81 	static struct sysinfo val;
82 	unsigned long ev[NR_VM_EVENT_ITEMS];
83 	struct appldata_mem_data *mem_data;
84 
85 	mem_data = data;
86 	mem_data->sync_count_1++;
87 
88 	all_vm_events(ev);
89 	mem_data->pgpgin     = ev[PGPGIN] >> 1;
90 	mem_data->pgpgout    = ev[PGPGOUT] >> 1;
91 	mem_data->pswpin     = ev[PSWPIN];
92 	mem_data->pswpout    = ev[PSWPOUT];
93 	mem_data->pgalloc    = ev[PGALLOC_NORMAL];
94 	mem_data->pgalloc    += ev[PGALLOC_DMA];
95 	mem_data->pgfault    = ev[PGFAULT];
96 	mem_data->pgmajfault = ev[PGMAJFAULT];
97 
98 	si_meminfo(&val);
99 	mem_data->sharedram = val.sharedram;
100 	mem_data->totalram  = P2K(val.totalram);
101 	mem_data->freeram   = P2K(val.freeram);
102 	mem_data->totalhigh = P2K(val.totalhigh);
103 	mem_data->freehigh  = P2K(val.freehigh);
104 	mem_data->bufferram = P2K(val.bufferram);
105 	mem_data->cached    = P2K(global_page_state(NR_FILE_PAGES)
106 				- val.bufferram);
107 
108 	si_swapinfo(&val);
109 	mem_data->totalswap = P2K(val.totalswap);
110 	mem_data->freeswap  = P2K(val.freeswap);
111 
112 	mem_data->timestamp = get_tod_clock();
113 	mem_data->sync_count_2++;
114 }
115 
116 
117 static struct appldata_ops ops = {
118 	.name      = "mem",
119 	.record_nr = APPLDATA_RECORD_MEM_ID,
120 	.size	   = sizeof(struct appldata_mem_data),
121 	.callback  = &appldata_get_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  */
132 static int __init appldata_mem_init(void)
133 {
134 	int ret;
135 
136 	ops.data = kzalloc(sizeof(struct appldata_mem_data), GFP_KERNEL);
137 	if (!ops.data)
138 		return -ENOMEM;
139 
140 	ret = appldata_register_ops(&ops);
141 	if (ret)
142 		kfree(ops.data);
143 
144 	return ret;
145 }
146 
147 /*
148  * appldata_mem_exit()
149  *
150  * unregister ops
151  */
152 static void __exit appldata_mem_exit(void)
153 {
154 	appldata_unregister_ops(&ops);
155 	kfree(ops.data);
156 }
157 
158 
159 module_init(appldata_mem_init);
160 module_exit(appldata_mem_exit);
161 
162 MODULE_LICENSE("GPL");
163 MODULE_AUTHOR("Gerald Schaefer");
164 MODULE_DESCRIPTION("Linux-VM Monitor Stream, MEMORY statistics");
165