如何将一个进程（线程）绑定到一个固定的CPU核上？——004

我会带着你远行 2022-06-06 23:48 236阅读 0赞

http://blog.csdn.net/sangyongjia/article/details/50725734

As multi-core CPUs become increasingly popular on server-grade hardware as well as end-user desktop PCs or laptops, there have been growing efforts in the community (e.g., in terms of programming models, compiler or operating system support) towards developing applications optimized for multi-core architecture.

One operating system (OS) support often exploited to run performance-critical applications on multi-core processors is so-called "processor affinity" or "CPU pinning". This is an OS-specific feature that "binds" a running process or program to particular CPU core(s).

Binding a program to specific CPU cores can be beneficial in several scenarios. For example, when an application with highly cache-bound workload runs together with other CPU-intensive jobs, pinning the application to a specific CPU would reduce CPU cache misses. Also, when two processes communicate via shared memory intensively, scheduling both processes on the cores in the same [NUMA domain][] would speed up their performance.

In this tutorial, I will describe how to run a program or process on specific CPU cores on Linux.

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google一圈，能够实现的方式有两种：第一种：linux的shell命令行方式，命令名字为taskset。第二种就是代码实现级别的了，pthread\_setaffinity\_np和sched\_setaffinity函数接口。

**第一种方式**我已经验证过了，确实可行。同时验证了我心中的疑问：如果将某个线程绑定到某个物理核上之后，在此线程运行结束前，会不会有别的线程被调度到此物理核上执行？  写了一个死循环验证了下，发现绑定之后是不会调度别的线程在此核上运行的！（肉眼观察的，时不时观察下，没发现别的线程在此核上执行；对比了下没有绑定的情况，会发现过段时间此线程就会被调度到别的核心上执行）

此种方式有个问题，就是只有线程运行起来后才会被绑定到某个核上，不够及时。

具体的方式为：

1.首先根据系统的差别运行如下安装命令：

sudo apt-get install util-linux        （Debian，Ubuntu or Linux Mint）

sudo yum install util-linux             （Fedora，CentOS or RHEL）

2.相关命令的使用：

2.1 使用命令 taskset  -p  <PID> 来获得此Process的 CPU affinity。

eg: taskset -p 2915  ------> pid 2915's current affinity mask:ff； ff=="1111  1111"，没一个1代表一个核，共8个核，能用的核数也为8个核。

2.2 使用命令 taskset -cp  <PID> 可获得数字形式的CPU affinity。

eg: taskset -cp 2915 ------> pid 2915's current affinity list: 0--7。

接下来为将进程pin到某个核上的命令；

2.3 taskset -p <COREMASK>  <PID>