[LTP] [PATCH] runpwtests03: use expr to calculate total_cpus for runpwtests03

[Po-Hsu Lin]

Thanks for the review,

They are both fine with me, if you want to see this to be changed into
the double parentheses form, I can send a V2 for that.

Cheers
PHLin

On Wed, Jun 26, 2019 at 10:55 AM Xiao Yang <ice_yangxiao@163.com> wrote:
>
> Hi,
>
> Sorry, I missed the fact that tst_ncpus is executable binary.
>
> It's good to me.
>
> Reviewed-by: Xiao Yang <ice_yangxiao@163.com>
>
> BTW: if you don't want to depend expr command, we can fix it by using
> total_cpus=$((total_cpus - 1)) instead.
>
> Best Regards,
> Xiao Yang
>
> On 06/26/2019 12:13 AM, Po-Hsu Lin wrote:
> > Hello!
> >
> > The $() here is for the tst_ncpus executable, which will return the
> > total cpu number.
> >
> > Thanks
> > PHLin
> >
> > On Tue, Jun 25, 2019 at 6:59 PM Xiao Yang <yangx.jy@cn.fujitsu.com> wrote:
> >> On 2019/06/25 18:03, Po-Hsu Lin wrote:
> >>> The arithmetic operation (( total_cpus-=1 )) does not work for dash,
> >>> which was symbolic linked to /bin/sh on some OS like Ubuntu.
> >>>
> >>> In such case, people will see error like:
> >>>     runpwtests03.sh: total_cpus-=1: not found
> >>>
> >>> And this further leads to access for a non-existing file and cause
> >>> false-positive result in the end:
> >>>     runpwtests03.sh: cannot create
> >>>     /sys/devices/system/cpu/cpu8/cpufreq/scaling_governor: Directory nonexistent
> >>>     runpwtests03.sh: FAIL: Unable to set governor -- powersave for cpu8
> >>>     Power_Management03 2 TFAIL: Changing governors
> >>>
> >>> Use expr instead for fix this issue.
> >>>
> >>> Signed-off-by: Po-Hsu Lin<po-hsu.lin@canonical.com>
> >>> ---
> >>>    testcases/kernel/power_management/runpwtests03.sh | 9 +++------
> >>>    1 file changed, 3 insertions(+), 6 deletions(-)
> >>>
> >>> diff --git a/testcases/kernel/power_management/runpwtests03.sh b/testcases/kernel/power_management/runpwtests03.sh
> >>> index 11197937f..3fb85d273 100755
> >>> --- a/testcases/kernel/power_management/runpwtests03.sh
> >>> +++ b/testcases/kernel/power_management/runpwtests03.sh
> >>> @@ -25,8 +25,7 @@ export TST_TOTAL=4
> >>>    . pm_include.sh
> >>>
> >>>    check_cpufreq_sysfs_files() {
> >>> -     total_cpus=$(tst_ncpus)
> >>> -     (( total_cpus-=1 ))
> >>> +     total_cpus=`expr $(tst_ncpus) - 1`
> >> Hi,
> >>
> >> It's wrong for single variable to use $(), did you mean ${tst_ncpus}?
> >>
> >> Best Regards,
> >> Xiao Yang
> >>>        RC=0
> >>>
> >>>        for cpu in $(seq 0 "${total_cpus}" )
> >>> @@ -51,8 +50,7 @@ check_cpufreq_sysfs_files() {
> >>>    change_govr() {
> >>>        available_govr=$(get_supporting_govr)
> >>>
> >>> -     total_cpus=$(tst_ncpus)
> >>> -     (( total_cpus-=1 ))
> >>> +     total_cpus=`expr $(tst_ncpus) - 1`
> >>>        RC=0
> >>>
> >>>        for cpu in $(seq 0 "${total_cpus}" )
> >>> @@ -79,8 +77,7 @@ change_freq() {
> >>>        available_govr=$(get_supporting_govr)
> >>>        RC=0
> >>>
> >>> -     total_cpus=$(tst_ncpus)
> >>> -     (( total_cpus-=1 ))
> >>> +     total_cpus=`expr $(tst_ncpus) - 1`
> >>>
> >>>        if ( echo ${available_govr} | grep -i "userspace" \
> >>>                >/dev/null 2>&1 ); then
> >>
> >>
>