148 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			148 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright 2015, Cyril Bur, IBM Corp.
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|  *
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|  * This program is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU General Public License
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|  * as published by the Free Software Foundation; either version
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|  * 2 of the License, or (at your option) any later version.
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|  *
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|  * This test attempts to see if the VSX registers change across preemption.
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|  * There is no way to be sure preemption happened so this test just
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|  * uses many threads and a long wait. As such, a successful test
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|  * doesn't mean much but a failure is bad.
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|  */
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| 
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| #include <stdio.h>
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| #include <string.h>
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| #include <unistd.h>
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| #include <sys/syscall.h>
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| #include <sys/time.h>
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| #include <sys/types.h>
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| #include <sys/wait.h>
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| #include <stdlib.h>
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| #include <pthread.h>
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| 
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| #include "utils.h"
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| 
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| /* Time to wait for workers to get preempted (seconds) */
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| #define PREEMPT_TIME 20
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| /*
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|  * Factor by which to multiply number of online CPUs for total number of
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|  * worker threads
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|  */
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| #define THREAD_FACTOR 8
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| 
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| /*
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|  * Ensure there is twice the number of non-volatile VMX regs!
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|  * check_vmx() is going to use the other half as space to put the live
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|  * registers before calling vsx_memcmp()
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|  */
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| __thread vector int varray[24] = {
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| 	{1, 2, 3, 4 }, {5, 6, 7, 8 }, {9, 10,11,12},
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| 	{13,14,15,16}, {17,18,19,20}, {21,22,23,24},
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| 	{25,26,27,28}, {29,30,31,32}, {33,34,35,36},
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| 	{37,38,39,40}, {41,42,43,44}, {45,46,47,48}
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| };
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| 
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| int threads_starting;
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| int running;
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| 
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| extern long preempt_vsx(vector int *varray, int *threads_starting, int *running);
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| 
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| long vsx_memcmp(vector int *a) {
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| 	vector int zero = {0, 0, 0, 0};
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| 	int i;
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| 
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| 	FAIL_IF(a != varray);
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| 
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| 	for(i = 0; i < 12; i++) {
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| 		if (memcmp(&a[i + 12], &zero, sizeof(vector int)) == 0) {
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| 			fprintf(stderr, "Detected zero from the VSX reg %d\n", i + 12);
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| 			return 2;
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| 		}
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| 	}
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| 
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| 	if (memcmp(a, &a[12], 12 * sizeof(vector int))) {
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| 		long *p = (long *)a;
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| 		fprintf(stderr, "VSX mismatch\n");
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| 		for (i = 0; i < 24; i=i+2)
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| 			fprintf(stderr, "%d: 0x%08lx%08lx | 0x%08lx%08lx\n",
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| 					i/2 + i%2 + 20, p[i], p[i + 1], p[i + 24], p[i + 25]);
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| 		return 1;
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| 	}
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| 	return 0;
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| }
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| 
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| void *preempt_vsx_c(void *p)
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| {
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| 	int i, j;
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| 	long rc;
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| 	srand(pthread_self());
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| 	for (i = 0; i < 12; i++)
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| 		for (j = 0; j < 4; j++) {
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| 			varray[i][j] = rand();
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| 			/* Don't want zero because it hides kernel problems */
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| 			if (varray[i][j] == 0)
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| 				j--;
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| 		}
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| 	rc = preempt_vsx(varray, &threads_starting, &running);
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| 	if (rc == 2)
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| 		fprintf(stderr, "Caught zeros in VSX compares\n");
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| 	return (void *)rc;
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| }
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| 
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| int test_preempt_vsx(void)
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| {
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| 	int i, rc, threads;
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| 	pthread_t *tids;
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| 
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| 	threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR;
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| 	tids = malloc(threads * sizeof(pthread_t));
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| 	FAIL_IF(!tids);
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| 
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| 	running = true;
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| 	threads_starting = threads;
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| 	for (i = 0; i < threads; i++) {
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| 		rc = pthread_create(&tids[i], NULL, preempt_vsx_c, NULL);
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| 		FAIL_IF(rc);
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| 	}
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| 
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| 	setbuf(stdout, NULL);
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| 	/* Not really nessesary but nice to wait for every thread to start */
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| 	printf("\tWaiting for %d workers to start...", threads_starting);
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| 	while(threads_starting)
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| 		asm volatile("": : :"memory");
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| 	printf("done\n");
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| 
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| 	printf("\tWaiting for %d seconds to let some workers get preempted...", PREEMPT_TIME);
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| 	sleep(PREEMPT_TIME);
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| 	printf("done\n");
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| 
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| 	printf("\tStopping workers...");
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| 	/*
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| 	 * Working are checking this value every loop. In preempt_vsx 'cmpwi r5,0; bne 2b'.
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| 	 * r5 will have loaded the value of running.
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| 	 */
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| 	running = 0;
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| 	for (i = 0; i < threads; i++) {
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| 		void *rc_p;
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| 		pthread_join(tids[i], &rc_p);
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| 
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| 		/*
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| 		 * Harness will say the fail was here, look at why preempt_vsx
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| 		 * returned
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| 		 */
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| 		if ((long) rc_p)
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| 			printf("oops\n");
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| 		FAIL_IF((long) rc_p);
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| 	}
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| 	printf("done\n");
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| 
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| 	return 0;
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| }
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| 
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| int main(int argc, char *argv[])
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| {
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| 	return test_harness(test_preempt_vsx, "vsx_preempt");
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| }
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