1 /* 2 * Copyright 2015, Cyril Bur, IBM Corp. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * This test attempts to see if the VMX registers change across preemption. 10 * Two things should be noted here a) The check_vmx function in asm only checks 11 * the non volatile registers as it is reused from the syscall test b) There is 12 * no way to be sure preemption happened so this test just uses many threads 13 * and a long wait. As such, a successful test doesn't mean much but a failure 14 * is bad. 15 */ 16 17 #include <stdio.h> 18 #include <unistd.h> 19 #include <sys/syscall.h> 20 #include <sys/time.h> 21 #include <sys/types.h> 22 #include <sys/wait.h> 23 #include <stdlib.h> 24 #include <pthread.h> 25 26 #include "utils.h" 27 28 /* Time to wait for workers to get preempted (seconds) */ 29 #define PREEMPT_TIME 20 30 /* 31 * Factor by which to multiply number of online CPUs for total number of 32 * worker threads 33 */ 34 #define THREAD_FACTOR 8 35 36 __thread vector int varray[] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10,11,12}, 37 {13,14,15,16},{17,18,19,20},{21,22,23,24}, 38 {25,26,27,28},{29,30,31,32},{33,34,35,36}, 39 {37,38,39,40},{41,42,43,44},{45,46,47,48}}; 40 41 int threads_starting; 42 int running; 43 44 extern void preempt_vmx(vector int *varray, int *threads_starting, int *running); 45 46 void *preempt_vmx_c(void *p) 47 { 48 int i, j; 49 srand(pthread_self()); 50 for (i = 0; i < 12; i++) 51 for (j = 0; j < 4; j++) 52 varray[i][j] = rand(); 53 54 /* Test fails if it ever returns */ 55 preempt_vmx(varray, &threads_starting, &running); 56 return p; 57 } 58 59 int test_preempt_vmx(void) 60 { 61 int i, rc, threads; 62 pthread_t *tids; 63 64 threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR; 65 tids = malloc(threads * sizeof(pthread_t)); 66 FAIL_IF(!tids); 67 68 running = true; 69 threads_starting = threads; 70 for (i = 0; i < threads; i++) { 71 rc = pthread_create(&tids[i], NULL, preempt_vmx_c, NULL); 72 FAIL_IF(rc); 73 } 74 75 setbuf(stdout, NULL); 76 /* Not really nessesary but nice to wait for every thread to start */ 77 printf("\tWaiting for all workers to start..."); 78 while(threads_starting) 79 asm volatile("": : :"memory"); 80 printf("done\n"); 81 82 printf("\tWaiting for %d seconds to let some workers get preempted...", PREEMPT_TIME); 83 sleep(PREEMPT_TIME); 84 printf("done\n"); 85 86 printf("\tStopping workers..."); 87 /* 88 * Working are checking this value every loop. In preempt_vmx 'cmpwi r5,0; bne 2b'. 89 * r5 will have loaded the value of running. 90 */ 91 running = 0; 92 for (i = 0; i < threads; i++) { 93 void *rc_p; 94 pthread_join(tids[i], &rc_p); 95 96 /* 97 * Harness will say the fail was here, look at why preempt_vmx 98 * returned 99 */ 100 if ((long) rc_p) 101 printf("oops\n"); 102 FAIL_IF((long) rc_p); 103 } 104 printf("done\n"); 105 106 return 0; 107 } 108 109 int main(int argc, char *argv[]) 110 { 111 return test_harness(test_preempt_vmx, "vmx_preempt"); 112 } 113