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https://github.com/cirosantilli/linux-kernel-module-cheat.git
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0d5c7f5c4c
And pass niters as a thread argument to all threading implementations... otherwise every loop has to do a memory load from the global!
50 lines
1.1 KiB
C
50 lines
1.1 KiB
C
/* https://cirosantilli.com/linux-kernel-module-cheat#atomic-c */
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#if __STDC_VERSION__ >= 201112L && !defined(__STDC_NO_THREADS__)
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#include <stdatomic.h>
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#include <stdio.h>
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#include <threads.h>
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#include <string.h>
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#include <stdlib.h>
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atomic_int acnt;
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int cnt;
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int my_thread_main(void *thr_data) {
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size_t niters = *(size_t *)thr_data;
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for (size_t i = 0; i < niters; ++i) {
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++cnt;
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++acnt;
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}
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return 0;
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}
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#endif
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int main(int argc, char **argv) {
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#if __STDC_VERSION__ >= 201112L && !defined(__STDC_NO_THREADS__)
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size_t niters, nthreads;
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thrd_t *threads;
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if (argc > 1) {
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nthreads = strtoull(argv[1], NULL, 0);
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} else {
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nthreads = 2;
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}
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if (argc > 2) {
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niters = strtoull(argv[2], NULL, 0);
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} else {
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niters = 10;
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}
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threads = malloc(sizeof(thrd_t) * nthreads);
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for(size_t i = 0; i < nthreads; ++i)
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thrd_create(threads + i, my_thread_main, &niters);
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for(size_t i = 0; i < nthreads; ++i)
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thrd_join(threads[i], NULL);
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free(threads);
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printf("atomic %u\n", acnt);
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printf("non-atomic %u\n", cnt);
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#else
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(void)argc;
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(void)argv;
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#endif
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}
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