Multi-Processing | 易学教程

手动分配CPU核

taskset -p f 1574                            
pid 1574's current affinity mask: 5
pid 1574's new affinity mask: f

taskset -c 
busybox  不支持

cat /proc/cpuinfo
Processor	: ARMv7 Processor rev 5 (v7l)
processor	: 0
BogoMIPS	: 5714.28

processor	: 1
BogoMIPS	: 5714.28

processor	: 2
BogoMIPS	: 5714.28

processor	: 3
BogoMIPS	: 5714.28

Features	: swp half thumb fastmult vfp edsp thumbee neon vfpv3 tls vfpv4 idiva idivt 
CPU implementer	: 0x41
CPU architecture: 7
CPU variant	: 0x0
CPU part	: 0xc07
CPU revision	: 5

Hardware	: sun8i
Revision	: 0000
Serial		: 2925032c2044fffff18f

系统调用

#include <sched.h>

// 设置进程号为pid的进程运行在mask所设定的CPU上
// 第二个参数cpusetsize是mask所指定的数的长度，我们通常设定为sizeof(cpu_set_t)

// 如果pid的值为0,则表示指定的是当前进程 
int sched_setaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask);

int sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask);

sched_setaffinity系统调用

CPU 使用率

busybox mpstat -P ALL

init.rc中的设置

    # this ensures that the cpusets are present and usable, but the device's
    # init.rc must actually set the correct cpus
    mkdir /dev/cpuset/foreground
    write /dev/cpuset/foreground/cpus 0
    write /dev/cpuset/foreground/mems 0
    mkdir /dev/cpuset/foreground/boost
    write /dev/cpuset/foreground/boost/cpus 0
    write /dev/cpuset/foreground/boost/mems 0
    mkdir /dev/cpuset/background
    write /dev/cpuset/background/cpus 0
    write /dev/cpuset/background/mems 0

    # system-background is for system tasks that should only run on
    # little cores, not on bigs
    # to be used only by init, so don't change system-bg permissions
    mkdir /dev/cpuset/system-background
    write /dev/cpuset/system-background/cpus 0
    write /dev/cpuset/system-background/mems 0

    # change permissions for all cpusets we'll touch at runtime
    chown system system /dev/cpuset
    chown system system /dev/cpuset/foreground
    chown system system /dev/cpuset/foreground/boost
    chown system system /dev/cpuset/background
    chown system system /dev/cpuset/tasks
    chown system system /dev/cpuset/foreground/tasks
    chown system system /dev/cpuset/foreground/boost/tasks
    chown system system /dev/cpuset/background/tasks
    chmod 0664 /dev/cpuset/foreground/tasks
    chmod 0664 /dev/cpuset/foreground/boost/tasks
    chmod 0664 /dev/cpuset/background/tasks
    chmod 0664 /dev/cpuset/tasks

调频

ondemand：按需调频，最大最小频率之间自动调整
interactive：类似“ondemand”，主要来说就是升频率快，降频慢。

来源：CSDN

作者：gbmaotai

链接：https://blog.csdn.net/gbmaotai/article/details/103453706

标签

affinity