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 <assert.h> 11 #include <libgen.h> 12 #include <bpf/bpf.h> 13 #include <scx/common.h> 14 #include "scx_simple.bpf.skel.h" 15 16 const char help_fmt[] = 17 "A simple sched_ext scheduler.\n" 18 "\n" 19 "See the top-level comment in .bpf.c for more details.\n" 20 "\n" 21 "Usage: %s [-f] [-v]\n" 22 "\n" 23 " -f Use FIFO scheduling instead of weighted vtime scheduling\n" 24 " -v Print libbpf debug messages\n" 25 " -h Display this help and exit\n"; 26 27 static bool verbose; 28 static volatile int exit_req; 29 30 static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args) 31 { 32 if (level == LIBBPF_DEBUG && !verbose) 33 return 0; 34 return vfprintf(stderr, format, args); 35 } 36 37 static void sigint_handler(int simple) 38 { 39 exit_req = 1; 40 } 41 42 static void read_stats(struct scx_simple *skel, __u64 *stats) 43 { 44 int nr_cpus = libbpf_num_possible_cpus(); 45 assert(nr_cpus > 0); 46 __u64 cnts[2][nr_cpus]; 47 __u32 idx; 48 49 memset(stats, 0, sizeof(stats[0]) * 2); 50 51 for (idx = 0; idx < 2; idx++) { 52 int ret, cpu; 53 54 ret = bpf_map_lookup_elem(bpf_map__fd(skel->maps.stats), 55 &idx, cnts[idx]); 56 if (ret < 0) 57 continue; 58 for (cpu = 0; cpu < nr_cpus; cpu++) 59 stats[idx] += cnts[idx][cpu]; 60 } 61 } 62 63 int main(int argc, char **argv) 64 { 65 struct scx_simple *skel; 66 struct bpf_link *link; 67 __u32 opt; 68 __u64 ecode; 69 70 libbpf_set_print(libbpf_print_fn); 71 signal(SIGINT, sigint_handler); 72 signal(SIGTERM, sigint_handler); 73 restart: 74 skel = SCX_OPS_OPEN(simple_ops, scx_simple); 75 76 while ((opt = getopt(argc, argv, "fvh")) != -1) { 77 switch (opt) { 78 case 'f': 79 skel->rodata->fifo_sched = true; 80 break; 81 case 'v': 82 verbose = true; 83 break; 84 default: 85 fprintf(stderr, help_fmt, basename(argv[0])); 86 return opt != 'h'; 87 } 88 } 89 90 SCX_OPS_LOAD(skel, simple_ops, scx_simple, uei); 91 link = SCX_OPS_ATTACH(skel, simple_ops, scx_simple); 92 93 while (!exit_req && !UEI_EXITED(skel, uei)) { 94 __u64 stats[2]; 95 96 read_stats(skel, stats); 97 printf("local=%llu global=%llu\n", stats[0], stats[1]); 98 fflush(stdout); 99 sleep(1); 100 } 101 102 bpf_link__destroy(link); 103 ecode = UEI_REPORT(skel, uei); 104 scx_simple__destroy(skel); 105 106 if (UEI_ECODE_RESTART(ecode)) 107 goto restart; 108 return 0; 109 } 110