总结！linux 消耗内存和cpu 定时任务

1. c脚本 消耗内存

1）在your_directory目录下，创建文件eatmem.c ,输入以下内容

2）编译：gcc eatmem.c -o eatmem

3) 创建定时任务，每15分钟执行：crontab -e  输入 */15 * * * *  /your_directory/eatmem >> /your_directory/memcron.log   wq保存，保存之后会生效。

#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
 
// Destription :   release memory
// 1.parameters#   gcc test_eatMem.c -o test_eatMem
// 2.parameters#   ./test_eatMem
// Date        :   2015-1-12
 
#define block 4 // eat times   4 block=1G
void eatMem()
{
 int i =0; int j = 0;
 
 int cell = 256 * 1024 * 1024; //256M   
 char * pMem[block]={0};    // init all pointer to NULL.
 for(i = 0; i < block; i++)
 {        
  pMem[i] = (char*)malloc(cell); // eat...    
  if(NULL == pMem[i]) // failed to eat.        
   {            
    printf("Insufficient memory avalible ,Cell %d Failure
", i);            
    break;        
  }
  
  memset(pMem[i], 0, cell);        
  printf("[%d]%d Bytes.
", i, cell);
  
  fflush(stdout);
  sleep(1);  
 }    
 
 //Read&Write 10 次，维持内存消耗的时间 可自己设置
 int nTimes = 0;
 for(nTimes = 0; nTimes < 10; nTimes++)
 { 
  for(i=0; i<block; i++)
  {
   printf("Read&Write [%d] cell.
", i);
   
   if(NULL == pMem[i])
   {
    continue;
   }
   
   char ch=0;
   int j=0;
   for(j=0; j<cell; j+=1024)
   {
    ch = pMem[i][j];
    pMem[i][j] = 'a';   
   }
   memset(pMem[i], 0, cell);
   
   fflush(stdout);   
   sleep(5);
  }
  
  sleep(5);
 }
 
 printf("Done! Start to release memory.
");
 //释放内存核心代码：    
 for(i = 0; i < block; i++)
 {
  printf("free[%d]
", i);
  if(NULL != pMem[i])        
  {            
   free(pMem[i]);    
   pMem[i] = NULL;
  }
  
  fflush(stdout);  
  sleep(2);          
 }    
  
 printf("Operation successfully!
");
 fflush(stdout);  
}
 
int main(int argc,char * args[])
{
   eatMem();
}

 2.shell脚本消耗内存

 占用1GB内存1个小时. 注意需要可以mount的权限

#!/bin/bash
mkdir /tmp/memory
mount -t tmpfs -o size=1024M tmpfs /tmp/memory
dd if=/dev/zero of=/tmp/memory/block
sleep 3600
rm /tmp/memory/block
umount /tmp/memory
rmdir /tmp/memory

3. shell脚本消耗CPU

1）创建脚本 eatcpu.sh 输入以下内容

2）消耗4台cpu，持续60s（可自己设置）：    ./eatcpu.sh 4 

#! /bin/sh  
# filename killcpu.sh 
if [ $# != 1 ] ; then 
  echo "USAGE: $0 <CPUs>"
  exit 1; 
fi
for i in `seq $1` 
do
  echo -ne "  
i=0;  
while true 
do 
i=i+1;  
done" | /bin/sh & 
  pid_array[$i]=$! ; 
done

time=$(date "+%Y-%m-%d %H:%M:%S")
echo "${time}"

for i in "${pid_array[@]}"; do
  echo 'kill ' $i ';'; 
done

sleep 60

for i in "${pid_array[@]}"; do
  kill $i;
done