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  */
  10 bool 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
  23 void 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 }