appldata_os.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Data gathering module for Linux-VM Monitor Stream, Stage 1.
  4 * Collects misc. OS related data (CPU utilization, running processes).
  5 *
  6 * Copyright IBM Corp. 2003, 2006
  7 *
  8 * Author: Gerald Schaefer <gerald.schaefer@de.ibm.com>
  9 */
 10
 11#define pr_fmt(fmt) "appldata: " 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 <linux/sched/loadavg.h>
 21#include <linux/sched/stat.h>
 22#include <asm/appldata.h>
 23#include <asm/smp.h>
 24
 25#include "appldata.h"
 26
 27/*
 28 * OS data
 29 *
 30 * This is accessed as binary data by z/VM. If changes to it can't be avoided,
 31 * the structure version (product ID, see appldata_base.c) needs to be changed
 32 * as well and all documentation and z/VM applications using it must be
 33 * updated.
 34 */
 35struct appldata_os_per_cpu {
 36	u32 per_cpu_user;	/* timer ticks spent in user mode   */
 37	u32 per_cpu_nice;	/* ... spent with modified priority */
 38	u32 per_cpu_system;	/* ... spent in kernel mode         */
 39	u32 per_cpu_idle;	/* ... spent in idle mode           */
 40
 41	/* New in 2.6 */
 42	u32 per_cpu_irq;	/* ... spent in interrupts          */
 43	u32 per_cpu_softirq;	/* ... spent in softirqs            */
 44	u32 per_cpu_iowait;	/* ... spent while waiting for I/O  */
 45
 46	/* New in modification level 01 */
 47	u32 per_cpu_steal;	/* ... stolen by hypervisor	    */
 48	u32 cpu_id;		/* number of this CPU		    */
 49} __attribute__((packed));
 50
 51struct appldata_os_data {
 52	u64 timestamp;
 53	u32 sync_count_1;	/* after VM collected the record data, */
 54	u32 sync_count_2;	/* sync_count_1 and sync_count_2 should be the
 55				   same. If not, the record has been updated on
 56				   the Linux side while VM was collecting the
 57				   (possibly corrupt) data */
 58
 59	u32 nr_cpus;		/* number of (virtual) CPUs        */
 60	u32 per_cpu_size;	/* size of the per-cpu data struct */
 61	u32 cpu_offset;		/* offset of the first per-cpu data struct */
 62
 63	u32 nr_running;		/* number of runnable threads      */
 64	u32 nr_threads;		/* number of threads               */
 65	u32 avenrun[3];		/* average nr. of running processes during */
 66				/* the last 1, 5 and 15 minutes */
 67
 68	/* New in 2.6 */
 69	u32 nr_iowait;		/* number of blocked threads
 70				   (waiting for I/O)               */
 71
 72	/* per cpu data */
 73	struct appldata_os_per_cpu os_cpu[];
 74} __attribute__((packed));
 75
 76static struct appldata_os_data *appldata_os_data;
 77
 78static struct appldata_ops ops = {
 79	.name	   = "os",
 80	.record_nr = APPLDATA_RECORD_OS_ID,
 81	.owner	   = THIS_MODULE,
 82	.mod_lvl   = {0xF0, 0xF1},		/* EBCDIC "01" */
 83};
 84
 85
 86/*
 87 * appldata_get_os_data()
 88 *
 89 * gather OS data
 90 */
 91static void appldata_get_os_data(void *data)
 92{
 93	int i, j, rc;
 94	struct appldata_os_data *os_data;
 95	unsigned int new_size;
 96
 97	os_data = data;
 98	os_data->sync_count_1++;
 99
100	os_data->nr_threads = nr_threads;
101	os_data->nr_running = nr_running();
102	os_data->nr_iowait  = nr_iowait();
103	os_data->avenrun[0] = avenrun[0] + (FIXED_1/200);
104	os_data->avenrun[1] = avenrun[1] + (FIXED_1/200);
105	os_data->avenrun[2] = avenrun[2] + (FIXED_1/200);
106
107	j = 0;
108	for_each_online_cpu(i) {
109		os_data->os_cpu[j].per_cpu_user =
110			nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_USER]);
111		os_data->os_cpu[j].per_cpu_nice =
112			nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_NICE]);
113		os_data->os_cpu[j].per_cpu_system =
114			nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM]);
115		os_data->os_cpu[j].per_cpu_idle =
116			nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_IDLE]);
117		os_data->os_cpu[j].per_cpu_irq =
118			nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_IRQ]);
119		os_data->os_cpu[j].per_cpu_softirq =
120			nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ]);
121		os_data->os_cpu[j].per_cpu_iowait =
122			nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_IOWAIT]);
123		os_data->os_cpu[j].per_cpu_steal =
124			nsecs_to_jiffies(kcpustat_cpu(i).cpustat[CPUTIME_STEAL]);
125		os_data->os_cpu[j].cpu_id = i;
126		j++;
127	}
128
129	os_data->nr_cpus = j;
130
131	new_size = struct_size(os_data, os_cpu, os_data->nr_cpus);
132	if (ops.size != new_size) {
133		if (ops.active) {
134			rc = appldata_diag(APPLDATA_RECORD_OS_ID,
135					   APPLDATA_START_INTERVAL_REC,
136					   (unsigned long) ops.data, new_size,
137					   ops.mod_lvl);
138			if (rc != 0)
139				pr_err("Starting a new OS data collection "
140				       "failed with rc=%d\n", rc);
141
142			rc = appldata_diag(APPLDATA_RECORD_OS_ID,
143					   APPLDATA_STOP_REC,
144					   (unsigned long) ops.data, ops.size,
145					   ops.mod_lvl);
146			if (rc != 0)
147				pr_err("Stopping a faulty OS data "
148				       "collection failed with rc=%d\n", rc);
149		}
150		ops.size = new_size;
151	}
152	os_data->timestamp = get_tod_clock();
153	os_data->sync_count_2++;
154}
155
156
157/*
158 * appldata_os_init()
159 *
160 * init data, register ops
161 */
162static int __init appldata_os_init(void)
163{
164	int rc, max_size;
165
166	max_size = struct_size(appldata_os_data, os_cpu, num_possible_cpus());
167	if (max_size > APPLDATA_MAX_REC_SIZE) {
168		pr_err("Maximum OS record size %i exceeds the maximum "
169		       "record size %i\n", max_size, APPLDATA_MAX_REC_SIZE);
170		rc = -ENOMEM;
171		goto out;
172	}
173
174	appldata_os_data = kzalloc(max_size, GFP_KERNEL | GFP_DMA);
175	if (appldata_os_data == NULL) {
176		rc = -ENOMEM;
177		goto out;
178	}
179
180	appldata_os_data->per_cpu_size = sizeof(struct appldata_os_per_cpu);
181	appldata_os_data->cpu_offset   = offsetof(struct appldata_os_data,
182							os_cpu);
183
184	ops.data = appldata_os_data;
185	ops.callback  = &appldata_get_os_data;
186	rc = appldata_register_ops(&ops);
187	if (rc != 0)
188		kfree(appldata_os_data);
189out:
190	return rc;
191}
192
193/*
194 * appldata_os_exit()
195 *
196 * unregister ops
197 */
198static void __exit appldata_os_exit(void)
199{
200	appldata_unregister_ops(&ops);
201	kfree(appldata_os_data);
202}
203
204
205module_init(appldata_os_init);
206module_exit(appldata_os_exit);
207
208MODULE_LICENSE("GPL");
209MODULE_AUTHOR("Gerald Schaefer");
210MODULE_DESCRIPTION("Linux-VM Monitor Stream, OS statistics");