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