1/******************************************************************************/
2/*                                                                            */
3/* Copyright (c) International Business Machines  Corp., 2007                 */
4/*                                                                            */
5/* This program is free software;  you can redistribute it and/or modify      */
6/* it under the terms of the GNU General Public License as published by       */
7/* the Free Software Foundation; either version 2 of the License, or          */
8/* (at your option) any later version.                                        */
9/*                                                                            */
10/* This program is distributed in the hope that it will be useful,            */
11/* but WITHOUT ANY WARRANTY;  without even the implied warranty of            */
12/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See                  */
13/* the GNU General Public License for more details.                           */
14/*                                                                            */
15/* You should have received a copy of the GNU General Public License          */
16/* along with this program;  if not, write to the Free Software               */
17/* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA    */
18/*                                                                            */
19/******************************************************************************/
20
21/******************************************************************************/
22/*                                                                            */
23/* File:        cpuctl_test01.c                                               */
24/*                                                                            */
25/* Description: This is a c program that tests the cpucontroller fairness of  */
26/*              scheduling the tasks according to their group shares. This    */
27/*              testcase tests the ability of the cpu controller to provide   */
28/*              fairness for share values (absolute).                         */
29/*                                                                            */
30/* Total Tests: 3                                                             */
31/*                                                                            */
32/* Test 01:     Tests if fairness persists among different runs               */
33/* Test 02:     Tests fairness with respect to absolute share values          */
34/* Test 03:     Granularity test with respect to shares values                */
35/*                                                                            */
36/* Test Name:   cpu_controller_test01                                         */
37/*                                                                            */
38/* Test Assertion                                                             */
39/*              Please refer to the file cpuctl_testplan.txt                  */
40/*                                                                            */
41/* Author:      Sudhir Kumar skumar@linux.vnet.ibm.com                        */
42/*                                                                            */
43/* History:                                                                   */
44/* Created-     20/12/2007 -Sudhir Kumar <skumar@linux.vnet.ibm.com>          */
45/*                                                                            */
46/******************************************************************************/
47
48#include <unistd.h>
49#include <math.h>
50#include <signal.h>
51#include <stdio.h>
52#include <stdlib.h>
53#include <string.h>
54#include <sys/resource.h>
55#include <sys/syscall.h>
56#include <sys/time.h>
57#include <sys/types.h>
58#include <sys/stat.h>
59#include <fcntl.h>
60#include <time.h>
61#include <unistd.h>
62
63#include "../libcontrollers/libcontrollers.h"
64#include "test.h"		/* LTP harness APIs */
65
66#define TIME_INTERVAL	30	/* Time interval in seconds */
67#define NUM_INTERVALS	3	/* How many iterations of TIME_INTERVAL */
68#define NUM_SETS	4	/* How many share values (with same ratio) */
69#define MULTIPLIER   	10	/* decides the rate at which share value gets multiplied */
70#define GRANULARITY    5	/* % value by which shares of a group changes */
71char *TCID = "cpuctl_test01";
72int TST_TOTAL = 1;
73pid_t scriptpid;
74char path[] = "/dev/cpuctl";
75extern void cleanup()
76{
77	kill(scriptpid, SIGUSR1);	/* Inform the shell to do cleanup */
78	tst_exit();		/* Report exit status */
79}
80
81volatile int timer_expired = 0;
82
83int main(int argc, char *argv[])
84{
85
86	int num_cpus;
87	int test_num;
88	int len;		/* Total time = TIME_INTERVAL *num_cpus in the machine */
89	char mygroup[FILENAME_MAX], mytaskfile[FILENAME_MAX];
90	char mysharesfile[FILENAME_MAX], ch;
91	pid_t pid;
92	gid_t my_group_num;	/* A number attached with a group */
93	int fd;			/* A descriptor to open a fifo for synchronized start */
94	int first_counter = 0;	/* To take n number of readings */
95	int second_counter = 0;	/* To track number of times the base value of shares has been changed */
96	double total_cpu_time,	/* Accumulated cpu time */
97	 delta_cpu_time,	/* Time the task could run on cpu(s) (in an interval) */
98	 prev_cpu_time = 0;
99	double exp_cpu_time;	/* Expected time in % as obtained by shares calculation */
100	struct rusage cpu_usage;
101	time_t current_time, prev_time, delta_time;
102	unsigned long int myshares = 2, baseshares = 1000;	/* Simply the base value to start with */
103	unsigned int fmyshares, num_tasks;	/* f-> from file. num_tasks is tasks in this group */
104	struct sigaction newaction, oldaction;
105
106	my_group_num = -1;
107	num_cpus = 0;
108	test_num = 0;
109
110	/* Signal handling for alarm */
111	sigemptyset(&newaction.sa_mask);
112	newaction.sa_handler = signal_handler_alarm;
113	newaction.sa_flags = 0;
114	sigaction(SIGALRM, &newaction, &oldaction);
115
116	/* Check if all parameters passed are correct */
117	if ((argc < 5) || ((my_group_num = atoi(argv[1])) <= 0)
118	    || ((scriptpid = atoi(argv[3])) <= 0)
119	    || ((num_cpus = atoi(argv[4])) <= 0)
120	    || (test_num = atoi(argv[5])) <= 0) {
121		tst_brkm(TBROK, cleanup, "Invalid input parameters\n");
122	}
123
124	if (test_num == 1)	/* Test 01 & Test 02 */
125		myshares *= my_group_num;
126	else if (test_num == 3)	/* Test 03 */
127		myshares = baseshares;
128	else {
129		tst_brkm(TBROK, cleanup,
130			 "Wrong Test number passed. Exiting Test...\n");
131	}
132
133	sprintf(mygroup, "%s", argv[2]);
134	sprintf(mytaskfile, "%s", mygroup);
135	sprintf(mysharesfile, "%s", mygroup);
136	strcat(mytaskfile, "/tasks");
137	strcat(mysharesfile, "/cpu.shares");
138	pid = getpid();
139	write_to_file(mytaskfile, "a", pid);	/* Assign the task to it's group */
140	write_to_file(mysharesfile, "w", myshares);
141
142	fd = open("./myfifo", 0);
143	if (fd == -1) {
144		tst_brkm(TBROK, cleanup,
145			 "Could not open fifo for synchronization");
146	}
147
148	fprintf(stdout, "\ntask-%d SHARES=%lu\n", my_group_num, myshares);
149	read(fd, &ch, 1);	/* To block all tasks here and fire them up at the same time */
150
151	/*
152	 * We now calculate the expected % cpu time of this task by getting
153	 * it's group's shares, the total shares of all the groups and the
154	 * number of tasks in this group.
155	 */
156	FLAG = 0;
157	total_shares = 0;
158	shares_pointer = &total_shares;
159	len = strlen(path);
160	if (!strncpy(fullpath, path, len))
161		tst_brkm(TBROK, cleanup, "Could not copy directory path %s ",
162			 path);
163
164	if (scan_shares_files(shares_pointer) != 0)
165		tst_brkm(TBROK, cleanup,
166			 "From function scan_shares_files in %s ", fullpath);
167
168	/* return val: -1 in case of function error, else 2 is min share value */
169	if ((fmyshares = read_shares_file(mysharesfile)) < 2)
170		tst_brkm(TBROK, cleanup, "in reading shares files  %s ",
171			 mysharesfile);
172
173	if ((read_file(mytaskfile, GET_TASKS, &num_tasks)) < 0)
174		tst_brkm(TBROK, cleanup, "in reading tasks files  %s ",
175			 mytaskfile);
176
177	exp_cpu_time = (double)(fmyshares * 100) / (total_shares * num_tasks);
178
179	prev_time = time(NULL);	/* Note down the time */
180
181	while (1) {
182		/* Need to run some cpu intensive task, which also frequently checks the timer value */
183		double f = 274.345, mytime;	/*just a float number to take sqrt */
184		alarm(TIME_INTERVAL);
185		timer_expired = 0;
186		while (!timer_expired)	/* Let the task run on cpu for TIME_INTERVAL */
187			f = sqrt(f * f);	/* Time of this operation should not be high otherwise we can
188						 * exceed the TIME_INTERVAL to measure cpu usage
189						 */
190		current_time = time(NULL);
191		delta_time = current_time - prev_time;	/* Duration in case its not exact TIME_INTERVAL */
192
193		getrusage(0, &cpu_usage);
194		total_cpu_time = (cpu_usage.ru_utime.tv_sec + cpu_usage.ru_utime.tv_usec * 1e-6 +	/*user */
195				  cpu_usage.ru_stime.tv_sec + cpu_usage.ru_stime.tv_usec * 1e-6);	/*sys */
196		delta_cpu_time = total_cpu_time - prev_cpu_time;
197
198		prev_cpu_time = total_cpu_time;
199		prev_time = current_time;
200
201		/* calculate % cpu time each task gets */
202		if (delta_time > TIME_INTERVAL)
203			mytime =
204			    (delta_cpu_time * 100) / (delta_time * num_cpus);
205		else
206			mytime =
207			    (delta_cpu_time * 100) / (TIME_INTERVAL * num_cpus);
208
209		fprintf(stdout, "task-%d:CPU TIME{calc:-%6.2f(s)i.e. %6.2f(%%) exp:-%6.2f(%%)}\
210with %lu(shares) in %lu (s) INTERVAL\n", my_group_num, delta_cpu_time, mytime,
211			exp_cpu_time, myshares, delta_time);
212		first_counter++;
213
214		if (first_counter >= NUM_INTERVALS) {	/* Take n sets of readings for each shares value */
215			first_counter = 0;
216			second_counter++;
217			if (second_counter >= NUM_SETS)
218				exit(0);	/* This task is done with its job */
219
220			/* Change share values depending on the test_num */
221			if (test_num == 1) {
222				/* Keep same ratio but change values */
223				myshares = MULTIPLIER * myshares;
224			} else {
225				/* Increase for odd task and decrease for even task */
226				if (my_group_num % 2)
227					myshares +=
228					    baseshares * GRANULARITY / 100;
229				else
230					myshares -=
231					    baseshares * GRANULARITY / 100;
232			}
233			write_to_file(mysharesfile, "w", myshares);
234			if (test_num == 3) {
235				/*
236				 * Read the shares file and again calculate the cpu fraction
237				 * No need to read tasks file as we do not migrate tasks
238				 * No need to scan all shares file as total shares are const
239				 */
240				if ((fmyshares =
241				     read_shares_file(mysharesfile)) < 2)
242					tst_brkm(TBROK, cleanup,
243						 "in reading shares files  %s ",
244						 mysharesfile);
245				exp_cpu_time =
246				    (double)(fmyshares * 100) / (total_shares *
247								 num_tasks);
248			}
249
250			fprintf(stdout, "\ntask-%d SHARES=%lu\n", my_group_num,
251				myshares);
252		}		/* end if */
253	}			/* end while */
254}				/* end main */
255