1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Copyright (c) 2022 Meta Platforms, Inc. and affiliates. 4 * Copyright (c) 2022 Tejun Heo <tj@kernel.org> 5 * Copyright (c) 2022 David Vernet <dvernet@meta.com> 6 */ 7 #include <stdio.h> 8 #include <unistd.h> 9 #include <signal.h> 10 #include <libgen.h> 11 #include <bpf/bpf.h> 12 #include <scx/common.h> 13 #include "scx_simple.bpf.skel.h" 14 15 const char help_fmt[] = 16 "A simple sched_ext scheduler.\n" 17 "\n" 18 "See the top-level comment in .bpf.c for more details.\n" 19 "\n" 20 "Usage: %s [-f] [-v]\n" 21 "\n" 22 " -f Use FIFO scheduling instead of weighted vtime scheduling\n" 23 " -v Print libbpf debug messages\n" 24 " -h Display this help and exit\n"; 25 26 static bool verbose; 27 static volatile int exit_req; 28 29 static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args) 30 { 31 if (level == LIBBPF_DEBUG && !verbose) 32 return 0; 33 return vfprintf(stderr, format, args); 34 } 35 36 static void sigint_handler(int simple) 37 { 38 exit_req = 1; 39 } 40 41 static void read_stats(struct scx_simple *skel, __u64 *stats) 42 { 43 int nr_cpus = libbpf_num_possible_cpus(); 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_simple *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 skel = SCX_OPS_OPEN(simple_ops, scx_simple); 73 74 while ((opt = getopt(argc, argv, "fvh")) != -1) { 75 switch (opt) { 76 case 'f': 77 skel->rodata->fifo_sched = true; 78 break; 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, simple_ops, scx_simple, uei); 89 link = SCX_OPS_ATTACH(skel, simple_ops, scx_simple); 90 91 while (!exit_req && !UEI_EXITED(skel, uei)) { 92 __u64 stats[2]; 93 94 read_stats(skel, stats); 95 printf("local=%llu global=%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_simple__destroy(skel); 103 104 if (UEI_ECODE_RESTART(ecode)) 105 goto restart; 106 return 0; 107 } 108