[LTP] [PATCH] cpuset_hotplug_test/cpuset_hotplug: Fix bug for obtaining task_cpus value in root_cpu_hotplug_test

[Samuel Zou]

Hi,

A friendly reminder for the two patchs in:

https://patchwork.ozlabs.org/project/ltp/patch/1617707717-63693-1-git-send-email-zou_wei@huawei.com/

https://patchwork.ozlabs.org/project/ltp/patch/1617701249-62196-1-git-send-email-zou_wei@huawei.com/

Can someone please review the patchs, comment, and if appropriate commit
them?

Regards,
Zou Wei

On 2021/4/6 17:27, Zou Wei wrote:
> --------------------------
> 
> 1. The method of obtaining $task_cpus from root_cpu_hotplug_test is
> incorrect, because the value of Cpus_allowed_list is related
> to /sys/devices/system/cpu/possible and
> /sys/devices/system/cpu/isolated.
> 
> 2. If isolcpus is configured in cmdline, the value of
> Cpus_allowed_list is equal to /sys/devices/system/cpu/possible minus
> /sys/devices/system/cpu/isolated. In this case, $task_cpus is inconsistent
> with $expect_task_cpus, test will be failed.
> 
> 3. Need to change the method of obtaining $task_cpu
> from /sys/devices/system/cpu/present.
> 
> 4. The description of cpu_present_mask:
>     Bitmap of CPUs currently present in the system.
>     Not all of them may be online. When physical hotplug is processed
>     by the relevant subsystem (e.g ACPI) can change and new bit either be
>     added or removed from the map depending on the event is
>     hot-add/hot-remove. There are currently no locking rules as of now.
>     Typical usage is to init topology during boot,
>     at which time hotplug is disabled.
> 
> Signed-off-by: Zou Wei <zou_wei@huawei.com>
> ---
>   .../controllers/cpuset/cpuset_hotplug_test/cpuset_hotplug_test.sh      | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/testcases/kernel/controllers/cpuset/cpuset_hotplug_test/cpuset_hotplug_test.sh b/testcases/kernel/controllers/cpuset/cpuset_hotplug_test/cpuset_hotplug_test.sh
> index 155e536..2c6993a 100755
> --- a/testcases/kernel/controllers/cpuset/cpuset_hotplug_test/cpuset_hotplug_test.sh
> +++ b/testcases/kernel/controllers/cpuset/cpuset_hotplug_test/cpuset_hotplug_test.sh
> @@ -93,8 +93,7 @@ root_cpu_hotplug_test()
>   
>   	root_cpus="`cat $CPUSET/cpuset.cpus`"
>   
> -	task_cpus="`cat /proc/$tst_pid/status | grep Cpus_allowed_list`"
> -	task_cpus="`echo $task_cpus | sed -e 's/Cpus_allowed_list: //'`"
> +	task_cpus="`cat /sys/devices/system/cpu/present`"
>   
>   	check_result "$root_cpus" "$expect_cpus"
>   	ret=$?
>