tools/testing/selftests/rcutorture/bin/cpus2use.sh

   1 #!/bin/bash
   2 #
   3 # Get an estimate of how CPU-hoggy to be.
   4 #
   5 # Usage: cpus2use.sh
   6 #
   7 # This program is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation; either version 2 of the License, or
  10 # (at your option) any later version.
  11 #
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program; if not, you can access it online at
  19 # http://www.gnu.org/licenses/gpl-2.0.html.
  20 #
  21 # Copyright (C) IBM Corporation, 2013
  22 #
  23 # Authors: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
  24
  25 ncpus=`grep '^processor' /proc/cpuinfo | wc -l`
  26 idlecpus=`mpstat | tail -1 | \
  27         awk -v ncpus=$ncpus '{ print ncpus * ($7 + $NF) / 100 }'`
  28 awk -v ncpus=$ncpus -v idlecpus=$idlecpus < /dev/null '
  29 BEGIN {
  30         cpus2use = idlecpus;
  31         if (cpus2use < 1)
  32                 cpus2use = 1;
  33         if (cpus2use < ncpus / 10)
  34                 cpus2use = ncpus / 10;
  35         if (cpus2use == int(cpus2use))
  36                 cpus2use = int(cpus2use)
  37         else
  38                 cpus2use = int(cpus2use) + 1
  39         print cpus2use;
  40 }'
  41