前言

最近大家都在积极的写博客呀，咸鱼也不能落下。

正文

需要注意的是， 下面的两种方法，我们获得的都是逻辑core的编号。 比如我的CPU是四核八线程，通过/proc/cpuinfo，就能看到8个core，编号0-7.而我们查看的话，也就是看位于core的编号是啥。。。

外部方法

主要通过ps命令来进行观察，

$ ps -o psr -p

程序中查看

在程序中通过sched_getcpu()可以查看当前进程当前所运行在哪个cpu，如果想要查看别的进程可以通过/proc//stat查看 查看的方式就有点粗暴了。

下面引用自stackoverflow

struct pstat

{

int pid; //process id

char tcomm[256];//filename of the executable

char state[2]; //state (R is running, S is sleeping, D is sleeping in an

//uninterruptible wait, Z is zombie, T is traced or stopped)

int ppid;// process id of the parent process

int pgrp;// pgrp of the process

int sid;// session id

int tty_nr;// tty the process uses

int tty_pgrp;// pgrp of the tty

int flags;// task flags

int min_flt;// number of minor faults

int cmin_flt;// number of minor faults with child's

int maj_flt;// number of major faults

int cmaj_flt;// number of major faults with child's

int utime;// user mode jiffies

int stime;// kernel mode jiffies

int cutime;// user mode jiffies with child's

int cstime;// kernel mode jiffies with child's

int priority;// priority level

int nice;// nice level

int num_threads;// number of threads

int it_real_value;// (obsolete, always 0)

int start_time;// time the process started after system boot

int vsize;// virtual memory size

int rss;// resident set memory size

int rsslim;// current limit in bytes on the rss

int start_code;// address above which program text can run

int end_code;// address below which program text can run

int start_stack;// address of the start of the stack

int esp;// current value of ESP

int eip;// current value of EIP

int pending;// bitmap of pending signals

int blocked;// bitmap of blocked signals

int sigign;// bitmap of ignored signals

int sigcatch;// bitmap of catched signals

int wchan;// address where process went to sleep

int i0;// (place holder)

int i1;// (place holder)

int exit_signal;// signal to send to parent thread on exit

int task_cpu;// which CPU the task is scheduled on

int rt_priority;// realtime priority

int policy;// scheduling policy (man sched_setscheduler)

int blkio_ticks;// time spent waiting for block IO

int gtime;// guest time of the task in jiffies

int cgtime;// guest time of the task children in jiffies

} p ;

int main()

{

char name[256];

char state[8];

FILE* f = fopen("/proc/pid/stat", "r"); //这里pid换成你想要查看的进程号

fscanf(f, "%d%s%s%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d%d",

&p.pid, &p.tcomm, &p.state, &p.ppid, &p.pgrp, &p.sid, &p.tty_nr, &p.tty_pgrp, &p.flags,

&p.min_flt, &p.cmin_flt, &p.maj_flt, &p.cmaj_flt, &p.utime, &p.stime, &p.cutime, &p.cstime,

&p.priority, &p.nice, &p.num_threads, &p.it_real_value, &p.start_time, &p.vsize, &p.rss,

&p.rsslim, &p.start_code, &p.end_code, &p.start_stack, &p.esp, &p.eip, &p.pending, &p.blocked,

&p.sigign, &p.sigcatch, &p.wchan, &p.i0, &p.i1, &p.exit_signal, &p.task_cpu, &p.rt_priority, &p.policy,

&p.blkio_ticks, &p.gtime, &p.cgtime);

printf("CPU %d\n", p.task_cpu);

return 0;

}

CPU指令

如果当前CPU支持的话（判断方法 $ cat /proc/cpuinfo | grep cpuid），直接调用指令CPUID。能获取CPU信息，不过这个方法好像和我们最初的需求–在哪个core上关系不大，只是拓展了解。