AIX 下获取系统CPU及内存的使用情况方法

  今天折腾了一下，本意如题，方法如下：

1.使用popen执行相关的命令，然后通过awk进行截取相关的数据。这种方法获取的数据精度不高。

2.访问/proc下的各个进程文件，打开各个文件访问每个进程的信息，然后进行统计计算。此种访求可能会有权限不够。另外，较复杂。具体实现参见Linux top.c 源码实现。

3.调用系统的相关接口API,获取CPU,内存等信息。AIX平台的相关帮助为：http://publib.boulder.ibm.com/infocenter/aix/v6r1/index.jsp?topic=/com.ibm.aix.prftools/doc/prftools/prftools07.htm

其方法一，二代码如下：

@1

#include <stdio.h>
#include <string.h>
#include <pthread.h>

static pthread_mutex_t popen_lock = PTHREAD_MUTEX_INITIALIZER;
int get_popen_result(char *cmd,char *result,int size)
{
	char buf[128] ={0};
	char *pStr = NULL;
	FILE* pfile = NULL;
	int lockRet = -1;
	int ret = 0;
	if(cmd == NULL || result == NULL || size <= 0)
	{
		return -1;
	}
	lockRet = pthread_mutex_trylock(&popen_lock);
	if(lockRet != 0)
	{
		perror("获取popen锁出错");
		return -1;
	}
	pfile = popen(cmd,"r");
	if(pfile == NULL)
	{
		perror("popen 出错");
		ret = -1;
		goto exit;
	}
	fflush(pfile);
	if((pStr = fgets(buf,sizeof(buf),pfile)) != NULL)
	{
		strncpy(result,buf,size);
	}
	pclose(pfile);
	exit:
		pthread_mutex_unlock(&popen_lock);
	return ret;
}
int get_cpu_mem_used(int *cpuUsed,float *memUsed)
{
   char result[128] = {0};
   int memTotal = 0;
   int memoryUsed  = 0;
   char temp[16] = {0};
   char *pPos = NULL;  
   double md = 0;
   int ret = get_popen_result("vmstat | awk 'NR==7 {print $14}'",result,sizeof(result));
   if(ret != -1)
   {
	   *cpuUsed = atol(result);
   }
   ret = get_popen_result("svmon -G | awk 'NR==2 {print $2,$3}'",result,sizeof(result));
   if(ret != -1 )
   {
	   pPos = strchr(result,32);
	   if(pPos != NULL);
	   {
		   strncpy(temp,result,pPos-result);
		   memTotal = atol(temp);
		   memset(temp,0,sizeof(temp));
		   strcpy(temp,pPos + 1);
		   memoryUsed  = atol(temp);
	   }
	   if(memTotal != 0 && memoryUsed != 0)
	   {
		  *memUsed = ((double)memoryUsed/(double)memTotal)*100; 
	   }	
   }
   return 0;
}
int main(int argc,char *argv[])
{	
   float memU = 0;
   int cpuU = 0;
   int i= 0;
   for(i= 0 ; i< 100; i++)
   {	   
	   get_cpu_mem_used(&cpuU,&memU);
       printf("cpu Used : %d , mem Used : %f \n", cpuU,memU );
	   sleep(2);
   }
   return 0;
}

@2

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <libperfstat.h>
#include <sys/systemcfg.h>

int get_perfstat_result(double*cpuUsed,double*memUsed)
{
    perfstat_cpu_total_t cpustat1,cpustat2;    
    perfstat_memory_total_t meminfo;
    u_longlong_t c1 =0,c2 =0,cpu_delta =0;

if (!perfstat_cpu_total(NULL, &cpustat1, sizeof(perfstat_cpu_total_t), 1)){
        perror("perfstat_cpu_total");
return-1;
    }  
    c1 = cpustat1.user + cpustat1.sys + cpustat1.idle + cpustat1.wait;
    sleep(1);
    
if (!perfstat_cpu_total(NULL, &cpustat2, sizeof(perfstat_cpu_total_t), 1)){
        perror("perfstat_cpu_total");
return-1;
    }  

if(!perfstat_memory_total(NULL, &meminfo, sizeof(perfstat_memory_total_t), 1)){
        perror("perfstat_memory_total");
return-1;
    }
    c2 = cpustat2.user + cpustat2.sys + cpustat2.idle + cpustat2.wait;
    cpu_delta = cpustat2.user + cpustat2.sys - cpustat1.user - cpustat1.sys; 

*cpuUsed =100.000* cpu_delta/(c2-c1) ;
*memUsed =100.000* (meminfo.real_inuse)/(meminfo.real_total) ;
    printf("CPU used : %6.2f , mem Used : %6.2f \n",*cpuUsed,*memUsed);
//printf("Total : %lu ,%lu\n",meminfo.real_total,meminfo.real_free+ meminfo.real_inuse);
}

int main(int argc,char* argv[])
{
int i=0;
double t1 =0.0,t2 =0.0;
for(i=0 ; i<200 ;i++)
    {
        get_perfstat_result(&t1,&t2);
    }
return0;
}

链接时参数为：xlC -q64 -g -o perf perf.c -lperfstat