LXR linux/tools/perf/arch/x86/util/group.c

   1// SPDX-License-Identifier: GPL-2.0
   2#include <stdio.h>
   3#include "api/fs/fs.h"
   4#include "util/group.h"
   5
   6/*
   7 * Check whether we can use a group for top down.
   8 * Without a group may get bad results due to multiplexing.
   9 */
  10bool arch_topdown_check_group(bool *warn)
  11{
  12        int n;
  13
  14        if (sysctl__read_int("kernel/nmi_watchdog", &n) < 0)
  15                return false;
  16        if (n > 0) {
  17                *warn = true;
  18                return false;
  19        }
  20        return true;
  21}
  22
  23void arch_topdown_group_warn(void)
  24{
  25        fprintf(stderr,
  26                "nmi_watchdog enabled with topdown. May give wrong results.\n"
  27                "Disable with echo 0 > /proc/sys/kernel/nmi_watchdog\n");
  28}
  29