linux-brain/tools/testing/selftests/rcutorture/bin/cpus2use.sh
Paul E. McKenney 7225c07772 torture: Make --cpus override idleness calculations
Currently, rcutorture will use relatively few CPUs to build the kernel
on a busy system, which is often as it should be.  However, if the user
has used the --cpus argument to dedicate a specified number of CPUs to
this torture test, it would be good if the kernel build also made use
of them.  This commit therefore changes the cpus2use.sh script to use
--cpus when specified and to do the idleness calculations otherwise.

Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
2019-05-28 09:06:09 -07:00

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#!/bin/bash
# SPDX-License-Identifier: GPL-2.0+
#
# Get an estimate of how CPU-hoggy to be.
#
# Usage: cpus2use.sh
#
# Copyright (C) IBM Corporation, 2013
#
# Authors: Paul E. McKenney <paulmck@linux.ibm.com>
if test -n "$TORTURE_ALLOTED_CPUS"
then
echo $TORTURE_ALLOTED_CPUS
exit 0
fi
ncpus=`grep '^processor' /proc/cpuinfo | wc -l`
idlecpus=`mpstat | tail -1 | \
awk -v ncpus=$ncpus '{ print ncpus * ($7 + $NF) / 100 }'`
awk -v ncpus=$ncpus -v idlecpus=$idlecpus < /dev/null '
BEGIN {
cpus2use = idlecpus;
if (cpus2use < 1)
cpus2use = 1;
if (cpus2use < ncpus / 10)
cpus2use = ncpus / 10;
if (cpus2use == int(cpus2use))
cpus2use = int(cpus2use)
else
cpus2use = int(cpus2use) + 1
print cpus2use;
}'