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 <stdlib.h> 9 #include <unistd.h> 10 #include <inttypes.h> 11 #include <signal.h> 12 #include <libgen.h> 13 #include <bpf/bpf.h> 14 #include <scx/common.h> 15 #include "scx_qmap.bpf.skel.h" 16 17 const char help_fmt[] = 18 "A simple five-level FIFO queue sched_ext scheduler.\n" 19 "\n" 20 "See the top-level comment in .bpf.c for more details.\n" 21 "\n" 22 "Usage: %s [-s SLICE_US] [-e COUNT] [-t COUNT] [-T COUNT] [-l COUNT] [-b COUNT]\n" 23 " [-d PID] [-D LEN] [-p] [-v]\n" 24 "\n" 25 " -s SLICE_US Override slice duration\n" 26 " -e COUNT Trigger scx_bpf_error() after COUNT enqueues\n" 27 " -t COUNT Stall every COUNT'th user thread\n" 28 " -T COUNT Stall every COUNT'th kernel thread\n" 29 " -l COUNT Trigger dispatch infinite looping after COUNT dispatches\n" 30 " -b COUNT Dispatch upto COUNT tasks together\n" 31 " -d PID Disallow a process from switching into SCHED_EXT (-1 for self)\n" 32 " -D LEN Set scx_exit_info.dump buffer length\n" 33 " -S Suppress qmap-specific debug dump\n" 34 " -p Switch only tasks on SCHED_EXT policy intead of all\n" 35 " -v Print libbpf debug messages\n" 36 " -h Display this help and exit\n"; 37 38 static bool verbose; 39 static volatile int exit_req; 40 41 static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args) 42 { 43 if (level == LIBBPF_DEBUG && !verbose) 44 return 0; 45 return vfprintf(stderr, format, args); 46 } 47 48 static void sigint_handler(int dummy) 49 { 50 exit_req = 1; 51 } 52 53 int main(int argc, char **argv) 54 { 55 struct scx_qmap *skel; 56 struct bpf_link *link; 57 int opt; 58 59 libbpf_set_print(libbpf_print_fn); 60 signal(SIGINT, sigint_handler); 61 signal(SIGTERM, sigint_handler); 62 63 skel = SCX_OPS_OPEN(qmap_ops, scx_qmap); 64 65 while ((opt = getopt(argc, argv, "s:e:t:T:l:b:d:D:Spvh")) != -1) { 66 switch (opt) { 67 case 's': 68 skel->rodata->slice_ns = strtoull(optarg, NULL, 0) * 1000; 69 break; 70 case 'e': 71 skel->bss->test_error_cnt = strtoul(optarg, NULL, 0); 72 break; 73 case 't': 74 skel->rodata->stall_user_nth = strtoul(optarg, NULL, 0); 75 break; 76 case 'T': 77 skel->rodata->stall_kernel_nth = strtoul(optarg, NULL, 0); 78 break; 79 case 'l': 80 skel->rodata->dsp_inf_loop_after = strtoul(optarg, NULL, 0); 81 break; 82 case 'b': 83 skel->rodata->dsp_batch = strtoul(optarg, NULL, 0); 84 break; 85 case 'd': 86 skel->rodata->disallow_tgid = strtol(optarg, NULL, 0); 87 if (skel->rodata->disallow_tgid < 0) 88 skel->rodata->disallow_tgid = getpid(); 89 break; 90 case 'D': 91 skel->struct_ops.qmap_ops->exit_dump_len = strtoul(optarg, NULL, 0); 92 break; 93 case 'S': 94 skel->rodata->suppress_dump = true; 95 break; 96 case 'p': 97 skel->struct_ops.qmap_ops->flags |= SCX_OPS_SWITCH_PARTIAL; 98 break; 99 case 'v': 100 verbose = true; 101 break; 102 default: 103 fprintf(stderr, help_fmt, basename(argv[0])); 104 return opt != 'h'; 105 } 106 } 107 108 SCX_OPS_LOAD(skel, qmap_ops, scx_qmap, uei); 109 link = SCX_OPS_ATTACH(skel, qmap_ops, scx_qmap); 110 111 while (!exit_req && !UEI_EXITED(skel, uei)) { 112 long nr_enqueued = skel->bss->nr_enqueued; 113 long nr_dispatched = skel->bss->nr_dispatched; 114 115 printf("stats : enq=%lu dsp=%lu delta=%ld reenq=%"PRIu64" deq=%"PRIu64"\n", 116 nr_enqueued, nr_dispatched, nr_enqueued - nr_dispatched, 117 skel->bss->nr_reenqueued, skel->bss->nr_dequeued); 118 fflush(stdout); 119 sleep(1); 120 } 121 122 bpf_link__destroy(link); 123 UEI_REPORT(skel, uei); 124 scx_qmap__destroy(skel); 125 /* 126 * scx_qmap implements ops.cpu_on/offline() and doesn't need to restart 127 * on CPU hotplug events. 128 */ 129 return 0; 130 } 131