Quelle perf.c Sprache: C

/************************************************************************/
/*         *      The Rocq Prover / The Rocq Development Team           */
/*  v      *         Copyright INRIA, CNRS and contributors             */
/* <O___,, * (see version control and CREDITS file for authors & dates) */
/*   \VV/  **************************************************************/
/*    //   *    This file is distributed under the terms of the         */
/*         *     GNU Lesser General Public License Version 2.1          */
/*         *     (see LICENSE file for the text of the license)         */
/************************************************************************/

#include <linux/perf_event.h>
#include <sys/syscall.h>
#include <sys/ioctl.h>
#include <unistd.h>

#include <errno.h>
#include <string.h>

#include <caml/mlvalues.h>
#include <caml/memory.h>
#include <caml/alloc.h>
#include <caml/fail.h>

static int perf_event_open(struct perf_event_attr *hw_event, pid_t pid,
                           int cpu, int group_fd, unsigned long flags) {
  return syscall(SYS_perf_event_open, hw_event, pid, cpu, group_fd, flags);
}

#define NOT_INITIALIZED (-2)

int fd = NOT_INITIALIZED;

CAMLprim value CAML_init(value unit) {
  CAMLparam1(unit);

  if (fd != NOT_INITIALIZED) {
    caml_failwith("counter already initialized");
  }

  struct perf_event_attr pe;
  memset(&pe, 0, sizeof(pe));

  pe.type = PERF_TYPE_HARDWARE;
  pe.size = sizeof(pe);
  pe.config = PERF_COUNT_HW_INSTRUCTIONS;
  pe.disabled = 1;
  pe.exclude_kernel = 1;
  pe.exclude_hv = 1;

  fd = perf_event_open(&pe, 0, -1, -1, 0);
  if (fd == -1) {
    fd = NOT_INITIALIZED;
    caml_failwith("initialisation failure");
  }

  if (ioctl(fd, PERF_EVENT_IOC_RESET , 0) == -1) {
    close(fd);
    fd = NOT_INITIALIZED;
    caml_failwith("could not initially reset counter");
  }

  if (ioctl(fd, PERF_EVENT_IOC_ENABLE, 0) == -1) {
    close(fd);
    fd = NOT_INITIALIZED;
    caml_failwith("could not initailly enable counter");
  }

  CAMLreturn(Val_unit);
}

CAMLprim value CAML_drop(value unit) {
  CAMLparam1(unit);

  if (fd == NOT_INITIALIZED) {
    caml_failwith("counter not initialized");
  }

  close(fd);
  fd = NOT_INITIALIZED;

  CAMLreturn(Val_unit);
}

CAMLprim value CAML_peek(value unit) {
  CAMLparam1(unit);

  if (fd == NOT_INITIALIZED) caml_failwith("counter not initialized");

  if (ioctl(fd, PERF_EVENT_IOC_DISABLE, 0) == -1) {
    caml_failwith("could not disable counter");
  }

  int64_t count = 0;
  size_t n = read(fd, &count, sizeof(count));

  if (n != sizeof(count)) {
    caml_failwith("could not retrieve counter");
  }

  value ret = caml_copy_int64(count);

  if (ioctl(fd, PERF_EVENT_IOC_ENABLE, 0) == -1) {
    caml_failwith("could not enable counter");
  }

  CAMLreturn(ret);
}

quality89%

¤ Dauer der Verarbeitung: 0.10 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.

Bemerkung:

Die farbliche Syntaxdarstellung ist noch experimentell.