PHP extension: php-affinity

PHP extension: php-affinity Php-affinity can bind processes to a cpu core by setting cpu affinity. In the following scenarios, we may want to modify the cpu affinity of processes:

• Frequent parallel operations

• Thread scalability test (simulate linear expansion by increasing the number of cpu cores)

• Time-sensitive and decisive processes

It provides methods for setting cpu affinity for open-source software such as nginx and swoole. Nginx officially recommends that the number of workers is equal to the number of cpu cores to bind a process to a cpu core and avoid overhead caused by process switching.

Php does not provide a function for setting cpu affinity. we can achieve this in two ways:

• Call the system command to modify the cpu affinity of the current process

• Compile php extensions to encapsulate system calls.

Php-affinity is a php extension written in c, Project address: https://github.com/huyanping/php-affinity

  /**                     * set CPU affinity                     *                     * @param $cpu_id                     * @return bool                     */                    functionsetaffinity($cpu_id){                        $num= getcpucores();                        if($cpu_id>= $num){                            returnfalse;                        }                        $set= system_call($cpu_id);                        if($set=== -1){                            returnfalse;                        }                                              returntrue;                    }                                          /**                     * get CPU affinity                     *                     * @return bool                     */                    functiongetaffinity(){                        $cpu_id= system_call();                        if($cpu_id=== -1){                            returnfalse;                        }                        return$cpu_id;                    }                                                                /**                     * get number of CPU                     *                     * @return bool                     */                    functiongetcpucores(){                        $nums= system_call();                        if($nums=== -1){                            returnfalse;                        }                        return$nums;                    }

Three functions are provided:

Setaffinity-set cpu affinity

Getaffinity-obtain cpu affinity

Getcpucores-obtain the number of cpu cores

The API is as follows:

References:

Https://zh.wikipedia.org/wiki/%E5%A4%84%E7%90%86%E5%99%A8%E4%BA%B2%E5%92%8C%E6%80%A7

Http://www.ibm.com/developerworks/cn/linux/l-affinity.html

Http://www.cnblogs.com/LubinLew/p/cpu_affinity.html

Project homepage:Http://www.open-open.com/lib/view/home/1448371981438