[LTP] 答复: [PATCH] memcg_use_hierarchy_test.sh: skip setting use_hierarchy if not available

[Yang Xu <xuyang2018.jy@cn.fujitsu.com>]

Hi Hanxiao

> Hi, Yang
>
>> -----????-----
>> ??: Re: [LTP] [PATCH] memcg_use_hierarchy_test.sh: skip setting
>> use_hierarchy if not available
>>
>> Hi hanxiao
>>
>>
>>> The precondition of this case is that we can disable use_hierarchy.
>>> But some distributions such as CentOS 8 had enabled it in root cgroup
>>> and hard to disabled.
> [snip]
>> /dev/memcg/memory.use_hierarchy" \
>>> +                                    "to 0 failed"
>>> +                        fi
>>> +                fi
>> I test this patch on centos7 and testcase2 skips. On centos7(without installing
>> docker), /sys/fs/cgroup/memory/memory.use_hierarchy value is equal to 1 and I
>> still can disable value for /dev/memcg/memory.use_hierarchy.
>>
> The behavior above looks conflicting with https://www.kernel.org/doc/Documentation/cgroup-v1/memory.txt.
Yes. Centos7 behavior is different from the documentation.
>> So why not directly use /dev/memcg/memory.use_hierarchy value to judge in
>> testcase after setting 0.
> In setup_test from memcg_lib.sh, we actually did:
>     mount -t cgroup -omemory memcg /dev/memcg
> Then kernel will find a suitable cgroup root for us in cgroup1_mount.
>
> In this case, /sys/fs/cgroup/memory/ would be the good choice.
> So it's equivalent to read memory.use_hierarchy from either side.
I understand. Only a minor suggestion, please use tabs instead of spaces
at the beginning of the line.


This patch looks good to me,
Acked-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>

@Li, I think this patch is ok, Do you have some comment about it?


Best Regards
Yang Xu


> Regards, 
> - Hanxiao
>> Best Regards
>> Yang Xu
>>>   	fi
>>>
>>>   	ROD mkdir "/dev/memcg/$TEST_ID"
>>> diff --git
>>> a/testcases/kernel/controllers/memcg/functional/memcg_use_hierarchy_te
>>> st.sh
>>> b/testcases/kernel/controllers/memcg/functional/memcg_use_hierarchy_te
>>> st.sh
>>> index 4cf6b9fc2..1439b6352 100755
>>> ---
>>> a/testcases/kernel/controllers/memcg/functional/memcg_use_hierarchy_te
>>> st.sh
>>> +++ b/testcases/kernel/controllers/memcg/functional/memcg_use_hierarch
>>> +++ y_test.sh
>>> @@ -34,7 +34,9 @@ TST_TOTAL=3
>>>   # test if one of the ancestors goes over its limit, the proces will be killed
>>>   testcase_1()
>>>   {
>>> -	echo 1 > memory.use_hierarchy
>>> +        if [ "$root_memory_use_hierarchy" != "1" ]; then
>>> +                echo 1 > memory.use_hierarchy
>>> +        fi
>>>   	echo $PAGESIZE > memory.limit_in_bytes
>>>
>>>   	mkdir subgroup
>>> @@ -48,6 +50,10 @@ testcase_1()
>>>   # test Enabling will fail if the cgroup already has other cgroups
>>>   testcase_2()
>>>   {
>>> +        if [ "$root_memory_use_hierarchy" = "1" ]; then
>>> +               tst_resm TCONF "root cgroup has use_hierarchy enabled,
>> skip"
>>> +               return
>>> +        fi
>>>   	mkdir subgroup
>>>   	EXPECT_FAIL echo 1 \> memory.use_hierarchy
>>>
>>> @@ -57,7 +63,9 @@ testcase_2()
>>>   # test disabling will fail if the parent cgroup has enabled hierarchy.
>>>   testcase_3()
>>>   {
>>> -	echo 1 > memory.use_hierarchy
>>> +        if [ "$root_memory_use_hierarchy" != "1" ]; then
>>> +               echo 1 > memory.use_hierarchy
>>> +        fi
>>>   	mkdir subgroup
>>>   	EXPECT_FAIL echo 0 \> subgroup/memory.use_hierarchy
>>>
>>>