| // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) |
| // Copyright (c) 2020 Wenbo Zhang |
| // |
| // Based on runqlen(8) from BCC by Brendan Gregg. |
| // 11-Sep-2020 Wenbo Zhang Created this. |
| #include <argp.h> |
| #include <signal.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <time.h> |
| #include <linux/perf_event.h> |
| #include <asm/unistd.h> |
| #include <bpf/libbpf.h> |
| #include <bpf/bpf.h> |
| #include "runqlen.h" |
| #include "runqlen.skel.h" |
| #include "btf_helpers.h" |
| #include "trace_helpers.h" |
| |
| #define max(x, y) ({ \ |
| typeof(x) _max1 = (x); \ |
| typeof(y) _max2 = (y); \ |
| (void) (&_max1 == &_max2); \ |
| _max1 > _max2 ? _max1 : _max2; }) |
| |
| struct env { |
| bool per_cpu; |
| bool runqocc; |
| bool timestamp; |
| bool host; |
| time_t interval; |
| int freq; |
| int times; |
| bool verbose; |
| } env = { |
| .interval = 99999999, |
| .times = 99999999, |
| .freq = 99, |
| }; |
| |
| static volatile bool exiting; |
| |
| const char *argp_program_version = "runqlen 0.1"; |
| const char *argp_program_bug_address = |
| "https://github.com/iovisor/bcc/tree/master/libbpf-tools"; |
| const char argp_program_doc[] = |
| "Summarize scheduler run queue length as a histogram.\n" |
| "\n" |
| "USAGE: runqlen [--help] [-C] [-O] [-T] [-f FREQUENCY] [interval] [count]\n" |
| "\n" |
| "EXAMPLES:\n" |
| " runqlen # summarize run queue length as a histogram\n" |
| " runqlen 1 10 # print 1 second summaries, 10 times\n" |
| " runqlen -T 1 # 1s summaries and timestamps\n" |
| " runqlen -O # report run queue occupancy\n" |
| " runqlen -C # show each CPU separately\n" |
| " runqlen -H # show nr_running from host's rq instead of cfs_rq\n" |
| " runqlen -f 199 # sample at 199HZ\n"; |
| |
| static const struct argp_option opts[] = { |
| { "cpus", 'C', NULL, 0, "Print output for each CPU separately" }, |
| { "frequency", 'f', "FREQUENCY", 0, "Sample with a certain frequency" }, |
| { "runqocc", 'O', NULL, 0, "Report run queue occupancy" }, |
| { "timestamp", 'T', NULL, 0, "Include timestamp on output" }, |
| { "verbose", 'v', NULL, 0, "Verbose debug output" }, |
| { "host", 'H', NULL, 0, "Report nr_running from host's rq" }, |
| { NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" }, |
| {}, |
| }; |
| |
| static error_t parse_arg(int key, char *arg, struct argp_state *state) |
| { |
| static int pos_args; |
| |
| switch (key) { |
| case 'h': |
| argp_state_help(state, stderr, ARGP_HELP_STD_HELP); |
| break; |
| case 'v': |
| env.verbose = true; |
| break; |
| case 'C': |
| env.per_cpu = true; |
| break; |
| case 'O': |
| env.runqocc = true; |
| break; |
| case 'T': |
| env.timestamp = true; |
| break; |
| case 'H': |
| env.host = true; |
| break; |
| case 'f': |
| errno = 0; |
| env.freq = strtol(arg, NULL, 10); |
| if (errno || env.freq <= 0) { |
| fprintf(stderr, "Invalid freq (in hz): %s\n", arg); |
| argp_usage(state); |
| } |
| break; |
| case ARGP_KEY_ARG: |
| errno = 0; |
| if (pos_args == 0) { |
| env.interval = strtol(arg, NULL, 10); |
| if (errno) { |
| fprintf(stderr, "invalid internal\n"); |
| argp_usage(state); |
| } |
| } else if (pos_args == 1) { |
| env.times = strtol(arg, NULL, 10); |
| if (errno) { |
| fprintf(stderr, "invalid times\n"); |
| argp_usage(state); |
| } |
| } else { |
| fprintf(stderr, |
| "unrecognized positional argument: %s\n", arg); |
| argp_usage(state); |
| } |
| pos_args++; |
| break; |
| default: |
| return ARGP_ERR_UNKNOWN; |
| } |
| return 0; |
| } |
| |
| static int nr_cpus; |
| |
| static int open_and_attach_perf_event(int freq, struct bpf_program *prog, |
| struct bpf_link *links[]) |
| { |
| struct perf_event_attr attr = { |
| .type = PERF_TYPE_SOFTWARE, |
| .freq = 1, |
| .sample_period = freq, |
| .config = PERF_COUNT_SW_CPU_CLOCK, |
| }; |
| int i, fd; |
| |
| for (i = 0; i < nr_cpus; i++) { |
| fd = syscall(__NR_perf_event_open, &attr, -1, i, -1, 0); |
| if (fd < 0) { |
| /* Ignore CPU that is offline */ |
| if (errno == ENODEV) |
| continue; |
| fprintf(stderr, "failed to init perf sampling: %s\n", |
| strerror(errno)); |
| return -1; |
| } |
| links[i] = bpf_program__attach_perf_event(prog, fd); |
| if (!links[i]) { |
| fprintf(stderr, "failed to attach perf event on cpu: %d\n", i); |
| close(fd); |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args) |
| { |
| if (level == LIBBPF_DEBUG && !env.verbose) |
| return 0; |
| return vfprintf(stderr, format, args); |
| } |
| |
| static void sig_handler(int sig) |
| { |
| exiting = true; |
| } |
| |
| static struct hist zero; |
| |
| static void print_runq_occupancy(struct runqlen_bpf__bss *bss) |
| { |
| struct hist hist; |
| int slot, i = 0; |
| float runqocc; |
| |
| do { |
| __u64 samples, idle = 0, queued = 0; |
| |
| hist = bss->hists[i]; |
| bss->hists[i] = zero; |
| for (slot = 0; slot < MAX_SLOTS; slot++) { |
| __u64 val = hist.slots[slot]; |
| |
| if (slot == 0) |
| idle += val; |
| else |
| queued += val; |
| } |
| samples = idle + queued; |
| runqocc = queued * 1.0 / max(1ULL, samples); |
| if (env.per_cpu) |
| printf("runqocc, CPU %-3d %6.2f%%\n", i, |
| 100 * runqocc); |
| else |
| printf("runqocc: %0.2f%%\n", 100 * runqocc); |
| } while (env.per_cpu && ++i < nr_cpus); |
| } |
| |
| static void print_linear_hists(struct runqlen_bpf__bss *bss) |
| { |
| struct hist hist; |
| int i = 0; |
| |
| do { |
| hist = bss->hists[i]; |
| bss->hists[i] = zero; |
| if (env.per_cpu) |
| printf("cpu = %d\n", i); |
| print_linear_hist(hist.slots, MAX_SLOTS, 0, 1, "runqlen"); |
| } while (env.per_cpu && ++i < nr_cpus); |
| } |
| |
| int main(int argc, char **argv) |
| { |
| LIBBPF_OPTS(bpf_object_open_opts, open_opts); |
| static const struct argp argp = { |
| .options = opts, |
| .parser = parse_arg, |
| .doc = argp_program_doc, |
| }; |
| struct bpf_link *links[MAX_CPU_NR] = {}; |
| struct runqlen_bpf *obj; |
| struct tm *tm; |
| char ts[32]; |
| int err, i; |
| time_t t; |
| |
| err = argp_parse(&argp, argc, argv, 0, NULL, NULL); |
| if (err) |
| return err; |
| |
| libbpf_set_print(libbpf_print_fn); |
| |
| nr_cpus = libbpf_num_possible_cpus(); |
| if (nr_cpus < 0) { |
| printf("failed to get # of possible cpus: '%s'!\n", |
| strerror(-nr_cpus)); |
| return 1; |
| } |
| if (nr_cpus > MAX_CPU_NR) { |
| fprintf(stderr, "the number of cpu cores is too big, please " |
| "increase MAX_CPU_NR's value and recompile"); |
| return 1; |
| } |
| |
| err = ensure_core_btf(&open_opts); |
| if (err) { |
| fprintf(stderr, "failed to fetch necessary BTF for CO-RE: %s\n", strerror(-err)); |
| return 1; |
| } |
| |
| obj = runqlen_bpf__open_opts(&open_opts); |
| if (!obj) { |
| fprintf(stderr, "failed to open BPF object\n"); |
| return 1; |
| } |
| |
| /* initialize global data (filtering options) */ |
| obj->rodata->targ_per_cpu = env.per_cpu; |
| obj->rodata->targ_host = env.host; |
| |
| err = runqlen_bpf__load(obj); |
| if (err) { |
| fprintf(stderr, "failed to load BPF object: %d\n", err); |
| goto cleanup; |
| } |
| |
| if (!obj->bss) { |
| fprintf(stderr, "Memory-mapping BPF maps is supported starting from Linux 5.7, please upgrade.\n"); |
| goto cleanup; |
| } |
| |
| err = open_and_attach_perf_event(env.freq, obj->progs.do_sample, links); |
| if (err) |
| goto cleanup; |
| |
| printf("Sampling run queue length... Hit Ctrl-C to end.\n"); |
| |
| signal(SIGINT, sig_handler); |
| |
| while (1) { |
| sleep(env.interval); |
| printf("\n"); |
| |
| if (env.timestamp) { |
| time(&t); |
| tm = localtime(&t); |
| strftime(ts, sizeof(ts), "%H:%M:%S", tm); |
| printf("%-8s\n", ts); |
| } |
| |
| if (env.runqocc) |
| print_runq_occupancy(obj->bss); |
| else |
| print_linear_hists(obj->bss); |
| |
| if (exiting || --env.times == 0) |
| break; |
| } |
| |
| cleanup: |
| for (i = 0; i < nr_cpus; i++) |
| bpf_link__destroy(links[i]); |
| runqlen_bpf__destroy(obj); |
| cleanup_core_btf(&open_opts); |
| |
| return err != 0; |
| } |