Quelle  scx_qmap.c   Sprache: C

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
 * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
 * Copyright (c) 2022 David Vernet <dvernet@meta.com>
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <inttypes.h>
#include <signal.h>
#include <libgen.h>
#include <bpf/bpf.h>
#include <scx/common.h>
#include "scx_qmap.bpf.skel.h"

const char help_fmt[] =
"A simple five-level FIFO queue sched_ext scheduler.\n"
"\n"
"See the top-level comment in .bpf.c for more details.\n"
"\n"
"Usage: %s [-s SLICE_US] [-e COUNT] [-t COUNT] [-T COUNT] [-l COUNT] [-b COUNT]\n"
" [-P] [-d PID] [-D LEN] [-p] [-v]\n"
"\n"
" -s SLICE_US Override slice duration\n"
" -e COUNT Trigger scx_bpf_error() after COUNT enqueues\n"
" -t COUNT Stall every COUNT'th user thread\n"
" -T COUNT Stall every COUNT'th kernel thread\n"
" -l COUNT Trigger dispatch infinite looping after COUNT dispatches\n"
" -b COUNT Dispatch upto COUNT tasks together\n"
" -P Print out DSQ content to trace_pipe every second, use with -b\n"
" -H Boost nice -20 tasks in SHARED_DSQ, use with -b\n"
" -d PID Disallow a process from switching into SCHED_EXT (-1 for self)\n"
" -D LEN Set scx_exit_info.dump buffer length\n"
" -S Suppress qmap-specific debug dump\n"
" -p Switch only tasks on SCHED_EXT policy instead of all\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;
}

int main(int argc, char **argv)
{
 struct scx_qmap *skel;
 struct bpf_link *link;
 int opt;

 libbpf_set_print(libbpf_print_fn);
 signal(SIGINT, sigint_handler);
 signal(SIGTERM, sigint_handler);

 skel = SCX_OPS_OPEN(qmap_ops, scx_qmap);

 skel->rodata->slice_ns = __COMPAT_ENUM_OR_ZERO("scx_public_consts", "SCX_SLICE_DFL");

 while ((opt = getopt(argc, argv, "s:e:t:T:l:b:PHd:D:Spvh")) != -1) {
  switch (opt) {
  case 's':
   skel->rodata->slice_ns = strtoull(optarg, NULL, 0) * 1000;
   break;
  case 'e':
   skel->bss->test_error_cnt = strtoul(optarg, NULL, 0);
   break;
  case 't':
   skel->rodata->stall_user_nth = strtoul(optarg, NULL, 0);
   break;
  case 'T':
   skel->rodata->stall_kernel_nth = strtoul(optarg, NULL, 0);
   break;
  case 'l':
   skel->rodata->dsp_inf_loop_after = strtoul(optarg, NULL, 0);
   break;
  case 'b':
   skel->rodata->dsp_batch = strtoul(optarg, NULL, 0);
   break;
  case 'P':
   skel->rodata->print_shared_dsq = true;
   break;
  case 'H':
   skel->rodata->highpri_boosting = true;
   break;
  case 'd':
   skel->rodata->disallow_tgid = strtol(optarg, NULL, 0);
   if (skel->rodata->disallow_tgid < 0)
    skel->rodata->disallow_tgid = getpid();
   break;
  case 'D':
   skel->struct_ops.qmap_ops->exit_dump_len = strtoul(optarg, NULL, 0);
   break;
  case 'S':
   skel->rodata->suppress_dump = true;
   break;
  case 'p':
   skel->struct_ops.qmap_ops->flags |= SCX_OPS_SWITCH_PARTIAL;
   break;
  case 'v':
   verbose = true;
   break;
  default:
   fprintf(stderr, help_fmt, basename(argv[0]));
   return opt != 'h';
  }
 }

 SCX_OPS_LOAD(skel, qmap_ops, scx_qmap, uei);
 link = SCX_OPS_ATTACH(skel, qmap_ops, scx_qmap);

 while (!exit_req && !UEI_EXITED(skel, uei)) {
  long nr_enqueued = skel->bss->nr_enqueued;
  long nr_dispatched = skel->bss->nr_dispatched;

  printf("stats : enq=%lu dsp=%lu delta=%ld reenq=%"PRIu64" deq=%"PRIu64" core=%"PRIu64" enq_ddsp=%"PRIu64"\n",
         nr_enqueued, nr_dispatched, nr_enqueued - nr_dispatched,
         skel->bss->nr_reenqueued, skel->bss->nr_dequeued,
         skel->bss->nr_core_sched_execed,
         skel->bss->nr_ddsp_from_enq);
  printf(" exp_local=%"PRIu64" exp_remote=%"PRIu64" exp_timer=%"PRIu64" exp_lost=%"PRIu64"\n",
         skel->bss->nr_expedited_local,
         skel->bss->nr_expedited_remote,
         skel->bss->nr_expedited_from_timer,
         skel->bss->nr_expedited_lost);
  if (__COMPAT_has_ksym("scx_bpf_cpuperf_cur"))
   printf("cpuperf: cur min/avg/max=%u/%u/%u target min/avg/max=%u/%u/%u\n",
          skel->bss->cpuperf_min,
          skel->bss->cpuperf_avg,
          skel->bss->cpuperf_max,
          skel->bss->cpuperf_target_min,
          skel->bss->cpuperf_target_avg,
          skel->bss->cpuperf_target_max);
  fflush(stdout);
  sleep(1);
 }

 bpf_link__destroy(link);
 UEI_REPORT(skel, uei);
 scx_qmap__destroy(skel);
 /*
 * scx_qmap implements ops.cpu_on/offline() and doesn't need to restart
 * on CPU hotplug events.
 */
 return 0;
}