1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (c) 2025 Meta Platforms, Inc. and affiliates. 4 * Copyright (c) 2025 Tejun Heo <tj@kernel.org> 5 */ 6 #include <stdio.h> 7 #include <unistd.h> 8 #include <signal.h> 9 #include <assert.h> 10 #include <libgen.h> 11 #include <bpf/bpf.h> 12 #include <scx/common.h> 13 #include "scx_cpu0.bpf.skel.h" 14 15 const char help_fmt[] = 16 "A cpu0 sched_ext scheduler.\n" 17 "\n" 18 "See the top-level comment in .bpf.c for more details.\n" 19 "\n" 20 "Usage: %s [-v]\n" 21 "\n" 22 " -v Print libbpf debug messages\n" 23 " -h Display this help and exit\n"; 24 25 static bool verbose; 26 static volatile int exit_req; 27 28 static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args) 29 { 30 if (level == LIBBPF_DEBUG && !verbose) 31 return 0; 32 return vfprintf(stderr, format, args); 33 } 34 35 static void sigint_handler(int sig) 36 { 37 exit_req = 1; 38 } 39 40 static void read_stats(struct scx_cpu0 *skel, __u64 *stats) 41 { 42 int nr_cpus = libbpf_num_possible_cpus(); 43 assert(nr_cpus > 0); 44 __u64 cnts[2][nr_cpus]; 45 __u32 idx; 46 47 memset(stats, 0, sizeof(stats[0]) * 2); 48 49 for (idx = 0; idx < 2; idx++) { 50 int ret, cpu; 51 52 ret = bpf_map_lookup_elem(bpf_map__fd(skel->maps.stats), 53 &idx, cnts[idx]); 54 if (ret < 0) 55 continue; 56 for (cpu = 0; cpu < nr_cpus; cpu++) 57 stats[idx] += cnts[idx][cpu]; 58 } 59 } 60 61 int main(int argc, char **argv) 62 { 63 struct scx_cpu0 *skel; 64 struct bpf_link *link; 65 __u32 opt; 66 __u64 ecode; 67 68 libbpf_set_print(libbpf_print_fn); 69 signal(SIGINT, sigint_handler); 70 signal(SIGTERM, sigint_handler); 71 restart: 72 optind = 1; 73 skel = SCX_OPS_OPEN(cpu0_ops, scx_cpu0); 74 75 skel->rodata->nr_cpus = libbpf_num_possible_cpus(); 76 77 while ((opt = getopt(argc, argv, "vh")) != -1) { 78 switch (opt) { 79 case 'v': 80 verbose = true; 81 break; 82 default: 83 fprintf(stderr, help_fmt, basename(argv[0])); 84 return opt != 'h'; 85 } 86 } 87 88 SCX_OPS_LOAD(skel, cpu0_ops, scx_cpu0, uei); 89 link = SCX_OPS_ATTACH(skel, cpu0_ops, scx_cpu0); 90 91 while (!exit_req && !UEI_EXITED(skel, uei)) { 92 __u64 stats[2]; 93 94 read_stats(skel, stats); 95 printf("local=%llu cpu0=%llu\n", stats[0], stats[1]); 96 fflush(stdout); 97 sleep(1); 98 } 99 100 bpf_link__destroy(link); 101 ecode = UEI_REPORT(skel, uei); 102 scx_cpu0__destroy(skel); 103 104 if (UEI_ECODE_RESTART(ecode)) 105 goto restart; 106 return 0; 107 } 108