linux/tools/testing/selftests/rcutorture/bin/cpus2use.sh
Paul E. McKenney 996a042e0a torture: Remove no-mpstat error message
The cpus2use.sh script complains if the mpstat command is not available,
and instead uses all available CPUs.  Unfortunately, this complaint
goes to stdout, where it confuses invokers who expect a single number.
This commit removes this error message in order to avoid this confusion.
The tendency of late has been to give rcutorture a full system, so this
should not cause issues.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2021-03-22 08:29:17 -07:00

40 lines
829 B
Bash
Executable File

#!/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 $TORTURE_ALLOTED_CPUS
exit 0
fi
ncpus=`grep '^processor' /proc/cpuinfo | wc -l`
if mpstat -V > /dev/null 2>&1
then
idlecpus=`mpstat | tail -1 | \
awk -v ncpus=$ncpus '{ print ncpus * ($7 + $NF) / 100 }'`
else
# No mpstat command, so use all available CPUs.
idlecpus=$ncpus
fi
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;
}'