Re: [PATCH v3 53/54] selftests/mm: run_vmtests.sh: free memory if available memory is low

[Sarthak Sharma <sarthak.sharma@arm.com>]

On 4/29/26 2:12 AM, Mike Rapoport wrote:
> From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>
> 
> Currently when running THP and HugeTLB tests, if HAVE_HUGEPAGES is set
> run_test() drops caches, compacts memory and runs the test. But if
> HAVE_HUGEPAGES is not set it skips the tests entirely, even if THP tests
> have nothing to do with HAVE_HUGEPAGES.
> 
> Replace the check if HAVE_HUGEPAGES is set with a check of how much memory
> is available. If there is less than 256 MB of available memory, drop caches
> and run compaction and then continue to run a test regardless of
> HAVE_HUGEPAGES value.
> 
> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

This patch looks good to me.

Reviewed-by: Sarthak Sharma <sarthak.sharma@arm.com>

> ---
>  tools/testing/selftests/mm/run_vmtests.sh | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
> index b9e520194634..b42d19036182 100755
> --- a/tools/testing/selftests/mm/run_vmtests.sh
> +++ b/tools/testing/selftests/mm/run_vmtests.sh
> @@ -99,6 +99,9 @@ EOF
>  	exit 0
>  }
>  
> +mem_available_kb=$(awk '/MemAvailable/ {print $2}' /proc/meminfo)
> +mem_available_Mb=$((mem_available_kb / 1024))
> +
>  RUN_ALL=false
>  RUN_DESTRUCTIVE=false
>  TAP_PREFIX="# "
> @@ -239,15 +242,12 @@ run_test() {
>  		# On memory constrainted systems some tests can fail to allocate hugepages.
>  		# perform some cleanup before the test for a higher success rate.
>  		if [ ${CATEGORY} == "thp" -o ${CATEGORY} == "hugetlb" ]; then
> -			if [ "${HAVE_HUGEPAGES}" = "1" ]; then
> -				echo 3 > /proc/sys/vm/drop_caches
> -				sleep 2
> -				echo 1 > /proc/sys/vm/compact_memory
> -				sleep 2
> -			else
> -				echo "hugepages not supported" | tap_prefix
> -				skip=1
> -			fi
> +		    if (( $mem_available_Mb < 256 )); then
> +			echo 3 > /proc/sys/vm/drop_caches
> +			sleep 2
> +			echo 1 > /proc/sys/vm/compact_memory
> +			sleep 2
> +		    fi
>  		fi
>  
>  		local test=$(pretty_name "$*")