[LTP] [PATCH V2] memcg_stress_test.sh: Fix reserved mem calculate

[Hao Ge]

When running this test case on a machine with large memory,
and without swap or swap is too small,existing reserved
memory is too small for a machine with large memory,and
will cause forking a subprocess to run a command will fail
due to memory is exhausted,so optimize reserved memory
calculate to ten percent of free memory.

Here is an example:

free -m
              total        used        free      shared  buff/cache   available
Mem:         260184        2959      255854          62        1370      236346
Swap:          4095           0        4095

when you run this testcase,console will report
fork：Cannot allocate memory

Signed-off-by: Hao Ge <gehao@kylinos.cn>
---
 .../kernel/controllers/memcg/stress/memcg_stress_test.sh    | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/testcases/kernel/controllers/memcg/stress/memcg_stress_test.sh b/testcases/kernel/controllers/memcg/stress/memcg_stress_test.sh
index cb52840d7..f26a9f72a 100755
--- a/testcases/kernel/controllers/memcg/stress/memcg_stress_test.sh
+++ b/testcases/kernel/controllers/memcg/stress/memcg_stress_test.sh
@@ -40,7 +40,7 @@ setup()
 	MEM=$(( $mem_free + $swap_free / 2 ))
 	MEM=$(( $MEM / 1024 ))
 	RUN_TIME=$(( 15 * 60 ))
-	[ "$pgsize" = "4096" ] && THREAD_SPARE_MB=1 || THREAD_SPARE_MB=8
+	RESERVED_MEMORY=$(( $MEM * 10/100 ))
 
 	tst_res TINFO "Calculated available memory $MEM MB"
 }
@@ -93,12 +93,12 @@ run_stress()
 
 test1()
 {
-	run_stress 150 $(( ($MEM - 150 * $THREAD_SPARE_MB) / 150 )) 5 $RUN_TIME
+	run_stress 150 $(( ($MEM - $RESERVED_MEMORY) / 150 )) 5 $RUN_TIME
 }
 
 test2()
 {
-	run_stress 1 $(( $MEM - $THREAD_SPARE_MB)) 5 $RUN_TIME
+	run_stress 1 $(( $MEM - $RESERVED_MEMORY)) 5 $RUN_TIME
 }
 
 . cgroup_lib.sh
-- 
2.25.1