Linux Kernel  3.7.1
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appldata_os.c
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1 /*
2  * Data gathering module for Linux-VM Monitor Stream, Stage 1.
3  * Collects misc. OS related data (CPU utilization, running processes).
4  *
5  * Copyright IBM Corp. 2003, 2006
6  *
7  * Author: Gerald Schaefer <[email protected]>
8  */
9 
10 #define KMSG_COMPONENT "appldata"
11 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
12 
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/errno.h>
17 #include <linux/kernel_stat.h>
18 #include <linux/netdevice.h>
19 #include <linux/sched.h>
20 #include <asm/appldata.h>
21 #include <asm/smp.h>
22 
23 #include "appldata.h"
24 
25 
26 #define LOAD_INT(x) ((x) >> FSHIFT)
27 #define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
28 
29 /*
30  * OS data
31  *
32  * This is accessed as binary data by z/VM. If changes to it can't be avoided,
33  * the structure version (product ID, see appldata_base.c) needs to be changed
34  * as well and all documentation and z/VM applications using it must be
35  * updated.
36  *
37  * The record layout is documented in the Linux for zSeries Device Drivers
38  * book:
39  * http://oss.software.ibm.com/developerworks/opensource/linux390/index.shtml
40  */
42  u32 per_cpu_user; /* timer ticks spent in user mode */
43  u32 per_cpu_nice; /* ... spent with modified priority */
44  u32 per_cpu_system; /* ... spent in kernel mode */
45  u32 per_cpu_idle; /* ... spent in idle mode */
46 
47  /* New in 2.6 */
48  u32 per_cpu_irq; /* ... spent in interrupts */
49  u32 per_cpu_softirq; /* ... spent in softirqs */
50  u32 per_cpu_iowait; /* ... spent while waiting for I/O */
51 
52  /* New in modification level 01 */
53  u32 per_cpu_steal; /* ... stolen by hypervisor */
54  u32 cpu_id; /* number of this CPU */
55 } __attribute__((packed));
56 
59  u32 sync_count_1; /* after VM collected the record data, */
60  u32 sync_count_2; /* sync_count_1 and sync_count_2 should be the
61  same. If not, the record has been updated on
62  the Linux side while VM was collecting the
63  (possibly corrupt) data */
64 
65  u32 nr_cpus; /* number of (virtual) CPUs */
66  u32 per_cpu_size; /* size of the per-cpu data struct */
67  u32 cpu_offset; /* offset of the first per-cpu data struct */
68 
69  u32 nr_running; /* number of runnable threads */
70  u32 nr_threads; /* number of threads */
71  u32 avenrun[3]; /* average nr. of running processes during */
72  /* the last 1, 5 and 15 minutes */
73 
74  /* New in 2.6 */
75  u32 nr_iowait; /* number of blocked threads
76  (waiting for I/O) */
77 
78  /* per cpu data */
80 } __attribute__((packed));
81 
83 
84 static struct appldata_ops ops = {
85  .name = "os",
86  .record_nr = APPLDATA_RECORD_OS_ID,
87  .owner = THIS_MODULE,
88  .mod_lvl = {0xF0, 0xF1}, /* EBCDIC "01" */
89 };
90 
91 
92 /*
93  * appldata_get_os_data()
94  *
95  * gather OS data
96  */
97 static void appldata_get_os_data(void *data)
98 {
99  int i, j, rc;
100  struct appldata_os_data *os_data;
101  unsigned int new_size;
103  os_data = data;
104  os_data->sync_count_1++;
105 
106  os_data->nr_threads = nr_threads;
107  os_data->nr_running = nr_running();
108  os_data->nr_iowait = nr_iowait();
109  os_data->avenrun[0] = avenrun[0] + (FIXED_1/200);
110  os_data->avenrun[1] = avenrun[1] + (FIXED_1/200);
111  os_data->avenrun[2] = avenrun[2] + (FIXED_1/200);
112 
113  j = 0;
115  os_data->os_cpu[j].per_cpu_user =
117  os_data->os_cpu[j].per_cpu_nice =
119  os_data->os_cpu[j].per_cpu_system =
121  os_data->os_cpu[j].per_cpu_idle =
123  os_data->os_cpu[j].per_cpu_irq =
125  os_data->os_cpu[j].per_cpu_softirq =
127  os_data->os_cpu[j].per_cpu_iowait =
129  os_data->os_cpu[j].per_cpu_steal =
131  os_data->os_cpu[j].cpu_id = i;
132  j++;
133  }
134 
135  os_data->nr_cpus = j;
136 
137  new_size = sizeof(struct appldata_os_data) +
138  (os_data->nr_cpus * sizeof(struct appldata_os_per_cpu));
139  if (ops.size != new_size) {
140  if (ops.active) {
143  (unsigned long) ops.data, new_size,
144  ops.mod_lvl);
145  if (rc != 0)
146  pr_err("Starting a new OS data collection "
147  "failed with rc=%d\n", rc);
148 
151  (unsigned long) ops.data, ops.size,
152  ops.mod_lvl);
153  if (rc != 0)
154  pr_err("Stopping a faulty OS data "
155  "collection failed with rc=%d\n", rc);
156  }
157  ops.size = new_size;
158  }
159  os_data->timestamp = get_clock();
160  os_data->sync_count_2++;
161 }
162 
163 
164 /*
165  * appldata_os_init()
166  *
167  * init data, register ops
168  */
169 static int __init appldata_os_init(void)
170 {
171  int rc, max_size;
172 
173  max_size = sizeof(struct appldata_os_data) +
174  (NR_CPUS * sizeof(struct appldata_os_per_cpu));
175  if (max_size > APPLDATA_MAX_REC_SIZE) {
176  pr_err("Maximum OS record size %i exceeds the maximum "
177  "record size %i\n", max_size, APPLDATA_MAX_REC_SIZE);
178  rc = -ENOMEM;
179  goto out;
180  }
181 
182  appldata_os_data = kzalloc(max_size, GFP_KERNEL | GFP_DMA);
183  if (appldata_os_data == NULL) {
184  rc = -ENOMEM;
185  goto out;
186  }
187 
188  appldata_os_data->per_cpu_size = sizeof(struct appldata_os_per_cpu);
189  appldata_os_data->cpu_offset = offsetof(struct appldata_os_data,
190  os_cpu);
191 
192  ops.data = appldata_os_data;
193  ops.callback = &appldata_get_os_data;
194  rc = appldata_register_ops(&ops);
195  if (rc != 0)
196  kfree(appldata_os_data);
197 out:
198  return rc;
199 }
200 
201 /*
202  * appldata_os_exit()
203  *
204  * unregister ops
205  */
206 static void __exit appldata_os_exit(void)
207 {
209  kfree(appldata_os_data);
210 }
211 
212 
213 module_init(appldata_os_init);
214 module_exit(appldata_os_exit);
215 
216 MODULE_LICENSE("GPL");
217 MODULE_AUTHOR("Gerald Schaefer");
218 MODULE_DESCRIPTION("Linux-VM Monitor Stream, OS statistics");