#!/bin/sh

KERNEL_REPO="https://github.com/rsalveti/linux.git"
TEST_TIME=$((6*60*60)) # 6 hours = 6 * 60 * 60 seconds
MEM_TRUNK=$(awk '/MemTotal/{printf "%d\n", $2 * 0.2;}' < /proc/meminfo)
BG_WORKER_NO=$(cat /proc/cpuinfo | grep processor | wc -l)

stress-ng --help > /dev/null 2>&1
if [ $? -ne 0 ];then
    sudo apt-get update
    sudo apt-get -y install stress-ng
fi

build_kernel()
{
    local build_kernel_pid

    # clone kernel source
    echo "Cloning kernel source from: ${KERNEL_REPO}"
    #git clone ${KERNEL_REPO}
    echo "Start building kernel.."
    cd linux
    make clean > /dev/null 2>&1
    make defconfig > /dev/null 2>&1
    make Image modules > ../build_kernel.log 2>&1 &
}

stress_ng_workload()
{
    echo "Start ${BG_WORKER_NO} background stress-ng workers.."
    stress-ng --random ${BG_WORKER_NO} > /dev/null 2>&1 &
}

mem_allocator()
{
    # allocate 20% of total memory
    stress-ng --vm-bytes ${MEM_TRUNK}k --vm-keep --vm 1 >/dev/null 2>&1 &
}

START_TIME=$(date +%s)

echo "Start background workload.."
#build_kernel
stress_ng_workload

echo "Start OOM test.."
while [ $(($(date +%s)-${START_TIME})) -lt ${TEST_TIME} ]
do
    echo -n "."
    mem_allocator

    sleep 5
done

# kill all stress-ng process
for p in `ps aux|grep stress-n[g]|awk '{print $2}'`
do
    kill -9 $p
done

echo "Test successfully!"
exit 0