// RUN: %libomp-compile // RUN: %libomp-run // RUN: env KMP_AFFINITY=none %libomp-run // REQUIRES: linux // Check if forked child process resets affinity properly by restricting // child's affinity to a subset of the parent and then checking it after // a parallel region #define _GNU_SOURCE #include "libomp_test_affinity.h" #include #include #include #include #include #include // Set the affinity mask of the calling thread to a proper subset of the // original affinity mask, specifically, one processor less. void set_subset_affinity(affinity_mask_t *mask) { int cpu; affinity_mask_t *original_mask = affinity_mask_alloc(); affinity_mask_copy(original_mask, mask); // Find first processor to clear for subset mask for (cpu = 0; cpu <= AFFINITY_MAX_CPUS; ++cpu) { if (affinity_mask_isset(original_mask, cpu)) { affinity_mask_clr(mask, cpu); break; } } affinity_mask_free(original_mask); set_thread_affinity(mask); } int main(int argc, char **argv) { char buf[1024] = {0}; char *other_buf; size_t n; int child_exit_status, exit_status; affinity_mask_t *mask = affinity_mask_alloc(); get_thread_affinity(mask); n = affinity_mask_snprintf(buf, sizeof(buf), mask); printf("Orignal Mask: %s\n", buf); if (affinity_mask_count(mask) == 1) { printf("Only one processor in affinity mask, skipping test.\n"); exit(EXIT_SUCCESS); } #pragma omp parallel { #pragma omp single printf("Hello! Thread %d executed single region in parent process\n", omp_get_thread_num()); } pid_t pid = fork(); if (pid < 0) { perror("fork()"); exit(EXIT_FAILURE); } if (pid == 0) { // Let child set a new initial mask set_subset_affinity(mask); #pragma omp parallel { #pragma omp single printf("Hello! Thread %d executed single region in child process\n", omp_get_thread_num()); } affinity_mask_t *new_mask = affinity_mask_alloc(); get_thread_affinity(new_mask); if (!affinity_mask_equal(mask, new_mask)) { affinity_mask_snprintf(buf, sizeof(buf), mask); fprintf(stderr, "Original Mask = %s\n", buf); affinity_mask_snprintf(buf, sizeof(buf), new_mask); fprintf(stderr, "New Mask = %s\n", buf); affinity_mask_free(new_mask); fprintf(stderr, "Child affinity mask did not reset properly\n"); exit(EXIT_FAILURE); } affinity_mask_free(new_mask); exit_status = EXIT_SUCCESS; } else { pid_t child_pid = pid; pid = wait(&child_exit_status); if (pid == -1) { perror("wait()"); exit(EXIT_FAILURE); } if (WIFEXITED(child_exit_status)) { exit_status = WEXITSTATUS(child_exit_status); } else { exit_status = EXIT_FAILURE; } } affinity_mask_free(mask); return exit_status; }