| // SPDX-License-Identifier: GPL-2.0 |
| // Carsten Haitzler <carsten.haitzler@arm.com>, 2021 |
| |
| // define this for gettid() |
| #define _GNU_SOURCE |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <string.h> |
| #include <pthread.h> |
| #include <sys/syscall.h> |
| #ifndef SYS_gettid |
| // gettid is 178 on arm64 |
| # define SYS_gettid 178 |
| #endif |
| #define gettid() syscall(SYS_gettid) |
| |
| struct args { |
| unsigned int loops; |
| pthread_t th; |
| void *ret; |
| }; |
| |
| static void *thrfn(void *arg) |
| { |
| struct args *a = arg; |
| int i = 0, len = a->loops; |
| |
| if (getenv("SHOW_TID")) { |
| unsigned long long tid = gettid(); |
| |
| printf("%llu\n", tid); |
| } |
| asm volatile( |
| "loop:\n" |
| "add %[i], %[i], #1\n" |
| "cmp %[i], %[len]\n" |
| "blt loop\n" |
| : /* out */ |
| : /* in */ [i] "r" (i), [len] "r" (len) |
| : /* clobber */ |
| ); |
| return (void *)(long)i; |
| } |
| |
| static pthread_t new_thr(void *(*fn) (void *arg), void *arg) |
| { |
| pthread_t t; |
| pthread_attr_t attr; |
| |
| pthread_attr_init(&attr); |
| pthread_create(&t, &attr, fn, arg); |
| return t; |
| } |
| |
| int main(int argc, char **argv) |
| { |
| unsigned int i, len, thr; |
| pthread_t threads[256]; |
| struct args args[256]; |
| |
| if (argc < 3) { |
| printf("ERR: %s [numthreads] [numloops (millions)]\n", argv[0]); |
| exit(1); |
| } |
| |
| thr = atoi(argv[1]); |
| if ((thr < 1) || (thr > 256)) { |
| printf("ERR: threads 1-256\n"); |
| exit(1); |
| } |
| len = atoi(argv[2]); |
| if ((len < 1) || (len > 4000)) { |
| printf("ERR: max loops 4000 (millions)\n"); |
| exit(1); |
| } |
| len *= 1000000; |
| for (i = 0; i < thr; i++) { |
| args[i].loops = len; |
| args[i].th = new_thr(thrfn, &(args[i])); |
| } |
| for (i = 0; i < thr; i++) |
| pthread_join(args[i].th, &(args[i].ret)); |
| return 0; |
| } |