[LTP] [PATCH v4 4/4] zram/zram01.sh: Use mem_used_total field instead of compr_data_size field

[Yang Xu]

Before ltp commit 4372f7a2156 ("Fix compression ratio calculation in zram01")[1], we
used free -m changes to calculate the compression ratio.

After the above patch, we used compr_data_size to calculate. kernel documentation[2] has
the following info:
orig_data_size: uncompressed size of data stored in this disk.
compr_data_size: compressed size of data stored in this disk
mem_used_total: the amount of memory allocated for this disk

We should calculate the compression ratio by used disk size divided into used mem size.
It can also avoid the situation that division by 0 as below:
zram01 7 TINFO: filling zram4 (it can take long time)
zram01 7 TPASS: zram4 was filled with '25568' KB
zram01 7 TINFO: compr_size 0
 /opt/ltp/testcases/bin/zram01.sh: line 131: 100 * 1024 * 25568 / 0: division by 0 (error token is "0")

Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
---
 testcases/kernel/device-drivers/zram/zram01.sh | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/testcases/kernel/device-drivers/zram/zram01.sh b/testcases/kernel/device-drivers/zram/zram01.sh
index 5e13f387c..5b4c05434 100755
--- a/testcases/kernel/device-drivers/zram/zram01.sh
+++ b/testcases/kernel/device-drivers/zram/zram01.sh
@@ -125,8 +125,8 @@ zram_fill_fs()
 			continue
 		fi
 
-		local compr_size=`awk '{print $2}' "/sys/block/zram$i/mm_stat"`
-		local v=$((100 * 1024 * $b / $compr_size))
+		local mem_used_total=`awk '{print $3}' "/sys/block/zram$i/mm_stat"`
+		local v=$((100 * 1024 * $b / $mem_used_total))
 		local r=`echo "scale=2; $v / 100 " | bc`
 
 		if [ "$v" -lt 100 ]; then
-- 
2.23.0