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

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