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Diffstat (limited to 'tools/sched_ext/scx_flatcg.c')
| -rw-r--r-- | tools/sched_ext/scx_flatcg.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/tools/sched_ext/scx_flatcg.c b/tools/sched_ext/scx_flatcg.c new file mode 100644 index 000000000000..5d24ca9c29d9 --- /dev/null +++ b/tools/sched_ext/scx_flatcg.c @@ -0,0 +1,233 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2023 Meta Platforms, Inc. and affiliates. + * Copyright (c) 2023 Tejun Heo <tj@kernel.org> + * Copyright (c) 2023 David Vernet <dvernet@meta.com> + */ +#include <stdio.h> +#include <signal.h> +#include <unistd.h> +#include <libgen.h> +#include <limits.h> +#include <inttypes.h> +#include <fcntl.h> +#include <time.h> +#include <bpf/bpf.h> +#include <scx/common.h> +#include "scx_flatcg.h" +#include "scx_flatcg.bpf.skel.h" + +#ifndef FILEID_KERNFS +#define FILEID_KERNFS 0xfe +#endif + +const char help_fmt[] = +"A flattened cgroup hierarchy sched_ext scheduler.\n" +"\n" +"See the top-level comment in .bpf.c for more details.\n" +"\n" +"Usage: %s [-s SLICE_US] [-i INTERVAL] [-f] [-v]\n" +"\n" +" -s SLICE_US Override slice duration\n" +" -i INTERVAL Report interval\n" +" -f Use FIFO scheduling instead of weighted vtime scheduling\n" +" -v Print libbpf debug messages\n" +" -h Display this help and exit\n"; + +static bool verbose; +static volatile int exit_req; + +static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args) +{ + if (level == LIBBPF_DEBUG && !verbose) + return 0; + return vfprintf(stderr, format, args); +} + +static void sigint_handler(int dummy) +{ + exit_req = 1; +} + +static float read_cpu_util(__u64 *last_sum, __u64 *last_idle) +{ + FILE *fp; + char buf[4096]; + char *line, *cur = NULL, *tok; + __u64 sum = 0, idle = 0; + __u64 delta_sum, delta_idle; + int idx; + + fp = fopen("/proc/stat", "r"); + if (!fp) { + perror("fopen(\"/proc/stat\")"); + return 0.0; + } + + if (!fgets(buf, sizeof(buf), fp)) { + perror("fgets(\"/proc/stat\")"); + fclose(fp); + return 0.0; + } + fclose(fp); + + line = buf; + for (idx = 0; (tok = strtok_r(line, " \n", &cur)); idx++) { + char *endp = NULL; + __u64 v; + + if (idx == 0) { + line = NULL; + continue; + } + v = strtoull(tok, &endp, 0); + if (!endp || *endp != '\0') { + fprintf(stderr, "failed to parse %dth field of /proc/stat (\"%s\")\n", + idx, tok); + continue; + } + sum += v; + if (idx == 4) + idle = v; + } + + delta_sum = sum - *last_sum; + delta_idle = idle - *last_idle; + *last_sum = sum; + *last_idle = idle; + + return delta_sum ? (float)(delta_sum - delta_idle) / delta_sum : 0.0; +} + +static void fcg_read_stats(struct scx_flatcg *skel, __u64 *stats) +{ + __u64 cnts[FCG_NR_STATS][skel->rodata->nr_cpus]; + __u32 idx; + + memset(stats, 0, sizeof(stats[0]) * FCG_NR_STATS); + + for (idx = 0; idx < FCG_NR_STATS; idx++) { + int ret, cpu; + + ret = bpf_map_lookup_elem(bpf_map__fd(skel->maps.stats), + &idx, cnts[idx]); + if (ret < 0) + continue; + for (cpu = 0; cpu < skel->rodata->nr_cpus; cpu++) + stats[idx] += cnts[idx][cpu]; + } +} + +int main(int argc, char **argv) +{ + struct scx_flatcg *skel; + struct bpf_link *link; + struct timespec intv_ts = { .tv_sec = 2, .tv_nsec = 0 }; + bool dump_cgrps = false; + __u64 last_cpu_sum = 0, last_cpu_idle = 0; + __u64 last_stats[FCG_NR_STATS] = {}; + unsigned long seq = 0; + __s32 opt; + __u64 ecode; + + libbpf_set_print(libbpf_print_fn); + signal(SIGINT, sigint_handler); + signal(SIGTERM, sigint_handler); +restart: + skel = SCX_OPS_OPEN(flatcg_ops, scx_flatcg); + + skel->rodata->nr_cpus = libbpf_num_possible_cpus(); + + while ((opt = getopt(argc, argv, "s:i:dfvh")) != -1) { + double v; + + switch (opt) { + case 's': + v = strtod(optarg, NULL); + skel->rodata->cgrp_slice_ns = v * 1000; + break; + case 'i': + v = strtod(optarg, NULL); + intv_ts.tv_sec = v; + intv_ts.tv_nsec = (v - (float)intv_ts.tv_sec) * 1000000000; + break; + case 'd': + dump_cgrps = true; + break; + case 'f': + skel->rodata->fifo_sched = true; + break; + case 'v': + verbose = true; + break; + case 'h': + default: + fprintf(stderr, help_fmt, basename(argv[0])); + return opt != 'h'; + } + } + + printf("slice=%.1lfms intv=%.1lfs dump_cgrps=%d", + (double)skel->rodata->cgrp_slice_ns / 1000000.0, + (double)intv_ts.tv_sec + (double)intv_ts.tv_nsec / 1000000000.0, + dump_cgrps); + + SCX_OPS_LOAD(skel, flatcg_ops, scx_flatcg, uei); + link = SCX_OPS_ATTACH(skel, flatcg_ops, scx_flatcg); + + while (!exit_req && !UEI_EXITED(skel, uei)) { + __u64 acc_stats[FCG_NR_STATS]; + __u64 stats[FCG_NR_STATS]; + float cpu_util; + int i; + + cpu_util = read_cpu_util(&last_cpu_sum, &last_cpu_idle); + + fcg_read_stats(skel, acc_stats); + for (i = 0; i < FCG_NR_STATS; i++) + stats[i] = acc_stats[i] - last_stats[i]; + + memcpy(last_stats, acc_stats, sizeof(acc_stats)); + + printf("\n[SEQ %6lu cpu=%5.1lf hweight_gen=%" PRIu64 "]\n", + seq++, cpu_util * 100.0, skel->data->hweight_gen); + printf(" act:%6llu deact:%6llu global:%6llu local:%6llu\n", + stats[FCG_STAT_ACT], + stats[FCG_STAT_DEACT], + stats[FCG_STAT_GLOBAL], + stats[FCG_STAT_LOCAL]); + printf("HWT cache:%6llu update:%6llu skip:%6llu race:%6llu\n", + stats[FCG_STAT_HWT_CACHE], + stats[FCG_STAT_HWT_UPDATES], + stats[FCG_STAT_HWT_SKIP], + stats[FCG_STAT_HWT_RACE]); + printf("ENQ skip:%6llu race:%6llu\n", + stats[FCG_STAT_ENQ_SKIP], + stats[FCG_STAT_ENQ_RACE]); + printf("CNS keep:%6llu expire:%6llu empty:%6llu gone:%6llu\n", + stats[FCG_STAT_CNS_KEEP], + stats[FCG_STAT_CNS_EXPIRE], + stats[FCG_STAT_CNS_EMPTY], + stats[FCG_STAT_CNS_GONE]); + printf("PNC next:%6llu empty:%6llu nocgrp:%6llu gone:%6llu race:%6llu fail:%6llu\n", + stats[FCG_STAT_PNC_NEXT], + stats[FCG_STAT_PNC_EMPTY], + stats[FCG_STAT_PNC_NO_CGRP], + stats[FCG_STAT_PNC_GONE], + stats[FCG_STAT_PNC_RACE], + stats[FCG_STAT_PNC_FAIL]); + printf("BAD remove:%6llu\n", + acc_stats[FCG_STAT_BAD_REMOVAL]); + fflush(stdout); + + nanosleep(&intv_ts, NULL); + } + + bpf_link__destroy(link); + ecode = UEI_REPORT(skel, uei); + scx_flatcg__destroy(skel); + + if (UEI_ECODE_RESTART(ecode)) + goto restart; + return 0; +} |