This is a note to let you know that I've just added the patch titled selftests/zram01.sh: Fix compression ratio calculation to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: selftests-zram01.sh-fix-compression-ratio-calculatio.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2e19dd861d9ba377c155a5cda5f44ebf0fa664b0 Author: Yang Xu <xuyang2018.jy@xxxxxxxxxxx> Date: Thu Jan 27 17:11:36 2022 +0800 selftests/zram01.sh: Fix compression ratio calculation [ Upstream commit d18da7ec3719559d6e74937266d0416e6c7e0b31 ] zram01 uses `free -m` to measure zram memory usage. The results are no sense because they are polluted by all running processes on the system. We Should only calculate the free memory delta for the current process. So use the third field of /sys/block/zram<id>/mm_stat to measure memory usage instead. The file is available since kernel 4.1. orig_data_size(first): uncompressed size of data stored in this disk. compr_data_size(second): compressed size of data stored in this disk mem_used_total(third): the amount of memory allocated for this disk Also remove useless zram cleanup call in zram_fill_fs and so we don't need to cleanup zram twice if fails. Signed-off-by: Yang Xu <xuyang2018.jy@xxxxxxxxxxx> Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/testing/selftests/zram/zram01.sh b/tools/testing/selftests/zram/zram01.sh index 114863d9fb876..e9e9eb777e2c7 100755 --- a/tools/testing/selftests/zram/zram01.sh +++ b/tools/testing/selftests/zram/zram01.sh @@ -33,8 +33,6 @@ zram_algs="lzo" zram_fill_fs() { - local mem_free0=$(free -m | awk 'NR==2 {print $4}') - for i in $(seq 0 $(($dev_num - 1))); do echo "fill zram$i..." local b=0 @@ -45,29 +43,17 @@ zram_fill_fs() b=$(($b + 1)) done echo "zram$i can be filled with '$b' KB" - done - local mem_free1=$(free -m | awk 'NR==2 {print $4}') - local used_mem=$(($mem_free0 - $mem_free1)) + local mem_used_total=`awk '{print $3}' "/sys/block/zram$i/mm_stat"` + local v=$((100 * 1024 * $b / $mem_used_total)) + if [ "$v" -lt 100 ]; then + echo "FAIL compression ratio: 0.$v:1" + ERR_CODE=-1 + return + fi - local total_size=0 - for sm in $zram_sizes; do - local s=$(echo $sm | sed 's/M//') - total_size=$(($total_size + $s)) + echo "zram compression ratio: $(echo "scale=2; $v / 100 " | bc):1: OK" done - - echo "zram used ${used_mem}M, zram disk sizes ${total_size}M" - - local v=$((100 * $total_size / $used_mem)) - - if [ "$v" -lt 100 ]; then - echo "FAIL compression ratio: 0.$v:1" - ERR_CODE=-1 - zram_cleanup - return - fi - - echo "zram compression ratio: $(echo "scale=2; $v / 100 " | bc):1: OK" } check_prereqs