[LTP] [PATCH] memcg_subgroup_charge: Remove limiting of parent

[Joerg Vehlow]

Hi

On 9/14/2021 10:34 AM, Richard Palethorpe via ltp wrote:
> It is not important how much memory is assigned to the parent
> group. The stated purpose of the test is to check no memory is
> assigned to the child group.
I still don't know why the test even wants to limit anything, when it is 
just checking what is charged.
So I would still vote for completely removing the limits and simplifying 
to just one test case.

But removing one limitation for now is a step in the right direction, so 
I will not argue anymore :)

>
> Also add the usage stats for the memcg_process because it appears
> the test will fail because the starting memory counter already
> includes some buffer/cache on linux-next. I'm not sure this
> is exactly what happens, but displaying the stats might help.
>
> Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
> Suggested-by: Joerg Vehlow <joerg.vehlow@aox-tech.de>
> Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
> ---
>   .../controllers/memcg/functional/memcg_lib.sh    |  2 +-
>   .../memcg/functional/memcg_subgroup_charge.sh    | 16 +++++-----------
>   2 files changed, 6 insertions(+), 12 deletions(-)
>
> diff --git a/testcases/kernel/controllers/memcg/functional/memcg_lib.sh b/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
> index ac9ad8268..1b76b6597 100755
> --- a/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
> +++ b/testcases/kernel/controllers/memcg/functional/memcg_lib.sh
> @@ -240,7 +240,7 @@ signal_memcg_process()
>   
>   		loops=$((loops - 1))
>   		if [ $loops -le 0 ]; then
> -			tst_brk TBROK "timed out on memory.usage_in_bytes"
> +			tst_brk TBROK "timed out on memory.usage_in_bytes" $usage $usage_start $size
>   		fi
>   	done
>   }
> diff --git a/testcases/kernel/controllers/memcg/functional/memcg_subgroup_charge.sh b/testcases/kernel/controllers/memcg/functional/memcg_subgroup_charge.sh
> index 3fa016102..cda624923 100755
> --- a/testcases/kernel/controllers/memcg/functional/memcg_subgroup_charge.sh
> +++ b/testcases/kernel/controllers/memcg/functional/memcg_subgroup_charge.sh
> @@ -18,22 +18,16 @@ TST_CNT=3
>   MEM_TO_ALLOC=$((PAGESIZES * 2))
>   
>   # Test the memory charge won't move to subgroup
> -# $1 - memory.limit_in_bytes in parent group
> -# $2 - memory.limit_in_bytes in sub group
> +# $1 - memory.limit_in_bytes in sub group
>   test_subgroup()
>   {
> -	local limit_parent=$1
> -	local limit_subgroup=$2
> +	local limit_subgroup=$1
>   
> -	if [ $limit_parent -ne 0 ]; then
> -		limit_parent=$(memcg_adjust_limit_for_kmem $limit_parent)
> -	fi
>   	if [ $limit_subgroup -ne 0 ]; then
>   		limit_subgroup=$(memcg_adjust_limit_for_kmem $limit_subgroup)
>   	fi
>   
>   	ROD mkdir subgroup
> -	EXPECT_PASS echo $limit_parent \> memory.limit_in_bytes
>   	EXPECT_PASS echo $limit_subgroup \> subgroup/memory.limit_in_bytes
>   
>   	start_memcg_process --mmap-anon -s $MEM_TO_ALLOC
> @@ -60,17 +54,17 @@ test_subgroup()
>   test1()
>   {
>   	tst_res TINFO "Test that group and subgroup have no relationship"
> -	test_subgroup $MEM_TO_ALLOC $((2 * MEM_TO_ALLOC))
> +	test_subgroup $((2 * MEM_TO_ALLOC))
>   }
>   
>   test2()
>   {
> -	test_subgroup $MEM_TO_ALLOC $MEM_TO_ALLOC
> +	test_subgroup $MEM_TO_ALLOC
>   }
>   
>   test3()
>   {
> -	test_subgroup $MEM_TO_ALLOC 0
> +	test_subgroup 0
>   }
>   
>   tst_run

Joerg