The process affinity of nginx in affinity

Nginx uses the multi-process master/worker structure, the worker process number is the CPU number is the highest efficiency, nginx through the affinity for each worker process binds a CPU, avoids the process switching to bring the consumption, simultaneously can guarantee the cache hit ratio.

Nginx configuration file conf/nginx.conf for the number of worker processes, and affinity configuration commands:

Worker_processes  4010000100001;

The application can invoke the interface settings proactively:

Linux process:

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

Example:

1 #define_gnu_source2 3#include <sched.h>4#include <unistd.h>5 6 voidDo_something (void);7 8 int 9Mainvoid)Ten { One pid_t pid; A cpu_set_t Mask; -  -     if(PID = fork ()) = =0){ the do_something (); -     } -Cpu_zero (&mask); -Cpu_set (0,&mask); +Sched_setaffinity (PID,sizeof(cpu_set_t),&mask); -  +     if(PID = fork ()) = =0){ A do_something (); at     } -Cpu_zero (&mask); -Cpu_set (1,&mask); -Sched_setaffinity (PID,sizeof(cpu_set_t),&mask); -  - wait (); in wait (); - }     to  + void -Do_something (void) the { *     inti; $      while(1){Panax Notoginsengi =1; -     }         the}

sched_setaffinity

FreeBSD can be set by calling Cpuset_setaffinity.

Nginx source SRC/OS/UNIX/NGINX_SETAFFINITY.C to achieve the compatibility of Linux and FreeBSD in the packaging, according to the configuration file set worker process affinity

Of course, POSIX threads can also set affinity:

int pthread_setaffinity_np (pthread_t thread, size_t cpusetsize,                                  const cpu_set_t *cpuset); int pthread_getaffinity_np (pthread_t thread, size_t cpusetsize,                                  *cpuset);

Processes that are already running can also be set by external commands:

       taskset [options] Mask command [ARG]        ... -p [Mask] pid

The process affinity of nginx in affinity