Re: [PATCH][V2] selftests: cpu-hotplug: fix case where CPUs offline > CPUs present

[Colin Ian King]

ping?

On 10/01/2019 12:38, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> 
> The cpu-hotplug test assumes that we can offline the maximum CPU as
> described by /sys/devices/system/cpu/offline.  However, in the case
> where the number of CPUs exceeds like kernel configuration then
> the offline count can be greater than the present count and we end
> up trying to test the offlining of a CPU that is not available to
> offline.  Fix this by testing the maximum present CPU instead.
> 
> Also, the test currently offlines the CPU and does not online it,
> so fix this by onlining the CPU after the test.
> 
> Fixes: d89dffa976bc ("fault-injection: add selftests for cpu and memory hotplug")
> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> 
> ---
> 
> V2: remove some debug and an empty line
> 
> ---
>  .../selftests/cpu-hotplug/cpu-on-off-test.sh        | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh b/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh
> index bab13dd025a6..0d26b5e3f966 100755
> --- a/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh
> +++ b/tools/testing/selftests/cpu-hotplug/cpu-on-off-test.sh
> @@ -37,6 +37,10 @@ prerequisite()
>  		exit $ksft_skip
>  	fi
>  
> +	present_cpus=`cat $SYSFS/devices/system/cpu/present`
> +	present_max=${present_cpus##*-}
> +	echo "present_cpus = $present_cpus present_max = $present_max"
> +
>  	echo -e "\t Cpus in online state: $online_cpus"
>  
>  	offline_cpus=`cat $SYSFS/devices/system/cpu/offline`
> @@ -151,6 +155,8 @@ online_cpus=0
>  online_max=0
>  offline_cpus=0
>  offline_max=0
> +present_cpus=0
> +present_max=0
>  
>  while getopts e:ahp: opt; do
>  	case $opt in
> @@ -190,9 +196,10 @@ if [ $allcpus -eq 0 ]; then
>  	online_cpu_expect_success $online_max
>  
>  	if [[ $offline_cpus -gt 0 ]]; then
> -		echo -e "\t offline to online to offline: cpu $offline_max"
> -		online_cpu_expect_success $offline_max
> -		offline_cpu_expect_success $offline_max
> +		echo -e "\t offline to online to offline: cpu $present_max"
> +		online_cpu_expect_success $present_max
> +		offline_cpu_expect_success $present_max
> +		online_cpu $present_max
>  	fi
>  	exit 0
>  else
>