1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright 2015, Cyril Bur, IBM Corp. 4 * 5 * This test attempts to see if the VMX registers change across preemption. 6 * Two things should be noted here a) The check_vmx function in asm only checks 7 * the non volatile registers as it is reused from the syscall test b) There is 8 * no way to be sure preemption happened so this test just uses many threads 9 * and a long wait. As such, a successful test doesn't mean much but a failure 10 * is bad. 11 */ 12 13 #include <stdio.h> 14 #include <unistd.h> 15 #include <sys/syscall.h> 16 #include <sys/time.h> 17 #include <sys/types.h> 18 #include <sys/wait.h> 19 #include <stdlib.h> 20 #include <pthread.h> 21 22 #include "utils.h" 23 24 /* Time to wait for workers to get preempted (seconds) */ 25 #define PREEMPT_TIME 20 26 /* 27 * Factor by which to multiply number of online CPUs for total number of 28 * worker threads 29 */ 30 #define THREAD_FACTOR 8 31 32 __thread vector int varray[] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10,11,12}, 33 {13,14,15,16},{17,18,19,20},{21,22,23,24}, 34 {25,26,27,28},{29,30,31,32},{33,34,35,36}, 35 {37,38,39,40},{41,42,43,44},{45,46,47,48}}; 36 37 int threads_starting; 38 int running; 39 40 extern void preempt_vmx(vector int *varray, int *threads_starting, int *running); 41 42 void *preempt_vmx_c(void *p) 43 { 44 int i, j; 45 srand(pthread_self()); 46 for (i = 0; i < 12; i++) 47 for (j = 0; j < 4; j++) 48 varray[i][j] = rand(); 49 50 /* Test fails if it ever returns */ 51 preempt_vmx(varray, &threads_starting, &running); 52 return p; 53 } 54 55 int test_preempt_vmx(void) 56 { 57 int i, rc, threads; 58 pthread_t *tids; 59 60 threads = sysconf(_SC_NPROCESSORS_ONLN) * THREAD_FACTOR; 61 tids = malloc(threads * sizeof(pthread_t)); 62 FAIL_IF(!tids); 63 64 running = true; 65 threads_starting = threads; 66 for (i = 0; i < threads; i++) { 67 rc = pthread_create(&tids[i], NULL, preempt_vmx_c, NULL); 68 FAIL_IF(rc); 69 } 70 71 setbuf(stdout, NULL); 72 /* Not really nessesary but nice to wait for every thread to start */ 73 printf("\tWaiting for all workers to start..."); 74 while(threads_starting) 75 asm volatile("": : :"memory"); 76 printf("done\n"); 77 78 printf("\tWaiting for %d seconds to let some workers get preempted...", PREEMPT_TIME); 79 sleep(PREEMPT_TIME); 80 printf("done\n"); 81 82 printf("\tStopping workers..."); 83 /* 84 * Working are checking this value every loop. In preempt_vmx 'cmpwi r5,0; bne 2b'. 85 * r5 will have loaded the value of running. 86 */ 87 running = 0; 88 for (i = 0; i < threads; i++) { 89 void *rc_p; 90 pthread_join(tids[i], &rc_p); 91 92 /* 93 * Harness will say the fail was here, look at why preempt_vmx 94 * returned 95 */ 96 if ((long) rc_p) 97 printf("oops\n"); 98 FAIL_IF((long) rc_p); 99 } 100 printf("done\n"); 101 102 return 0; 103 } 104 105 int main(int argc, char *argv[]) 106 { 107 return test_harness(test_preempt_vmx, "vmx_preempt"); 108 } 109