OPcache 通过将 PHP 脚本预编译的字节码存储到共享内存中来提升 PHP 的性能, 存储预编译字节码的好处就是 省去了每次加载和解析 PHP 脚本的开销。
PHP 5.5.0 及后续版本中已经绑定了 OPcache 扩展。 对于 PHP 5.2,5.3 和 5.4 版本可以使用 » PECL 扩展中的 OPcache 库。


OPcache 只能编译为共享扩展。 如果你使用 --disable-all 参数 禁用了默认扩展的构建, 那么必须使用 --enable-opcache 选项来开启 OPcache。
编译之后,就可以使用 zend_extension 指令来将 OPcache 扩展加载到 PHP 中。在非 Windows 平台使用 zend_extension=/full/path/to/,
Windows平台使用 zend_extension=C:\path\to\php_opcache.dll

PHP 5.2,5.3和 5.4版本中没有和PHP捆绑,需要自行安装,这里不做说明。


使用下列推荐设置来获得较好的 性能:

你也可以禁用 opcache.save_comments 并且启用 opcache.enable_file_override。 需要提醒的是,在生产环境中使用上述配置之前,必须经过严格测试。 因为上述配置存在一个已知问题,它会引发一些框架和应用的异常, 尤其是在存在文档使用了备注注解的时候。



PHP Warning: PHP Startup: Invalid library (appears to be a Zend Extension, try loading using from php.ini) in Unknown on line 0




;设置共享内存大小, 单位为:Mb


检查脚本时间戳是否有更新的周期,以秒为单位。 设置为 0 会导致针对每个请求, OPcache 都会检查脚本更新

如果启用,那么 OPcache 会每隔 opcache.revalidate_freq 设定的秒数 检查脚本是否更新。 如果禁用此选项,你必须使用 opcache_reset() 或者 opcache_invalidate() 函数来手动重置 OPcache,也可以 通过重启 Web 服务器来使文件系统更改生效。


下面是OPcache 可用的配置指令完整列表:

; Determines if Zend OPCache is enabled

; Determines if Zend OPCache is enabled for the CLI version of PHP

; The OPcache shared memory storage size.

; The amount of memory for interned strings in Mbytes.

; The maximum number of keys (scripts) in the OPcache hash table.
; Only numbers between 200 and 1000000 are allowed.

; The maximum percentage of "wasted" memory until a restart is scheduled.

; When this directive is enabled, the OPcache appends the current working
; directory to the script key, thus eliminating possible collisions between
; files with the same name (basename). Disabling the directive improves
; performance, but may break existing applications.

; When disabled, you must reset the OPcache manually or restart the
; webserver for changes to the filesystem to take effect.

; How often (in seconds) to check file timestamps for changes to the shared
; memory storage allocation. ("1" means validate once per second, but only
; once per request. "0" means always validate)

; Enables or disables file search in include_path optimization

; If disabled, all PHPDoc comments are dropped from the code to reduce the
; size of the optimized code.

; If enabled, a fast shutdown sequence is used for the accelerated code
; Depending on the used Memory Manager this may cause some incompatibilities.

; Allow file existence override (file_exists, etc.) performance feature.

; A bitmask, where each bit enables or disables the appropriate OPcache
; passes


; The location of the OPcache blacklist file (wildcards allowed).
; Each OPcache blacklist file is a text file that holds the names of files
; that should not be accelerated. The file format is to add each filename
; to a new line. The filename may be a full path or just a file prefix
; (i.e., /var/www/x  blacklists all the files and directories in /var/www
; that start with 'x'). Line starting with a ; are ignored (comments).

; Allows exclusion of large files from being cached. By default all files
; are cached.

; Check the cache checksum each N requests.
; The default value of "0" means that the checks are disabled.

; How long to wait (in seconds) for a scheduled restart to begin if the cache
; is not being accessed.

; OPcache error_log file name. Empty string assumes "stderr".

; All OPcache errors go to the Web server log.
; By default, only fatal errors (level 0) or errors (level 1) are logged.
; You can also enable warnings (level 2), info messages (level 3) or
; debug messages (level 4).

; Preferred Shared Memory back-end. Leave empty and let the system decide.

; Protect the shared memory from unexpected writing during script execution.
; Useful for internal debugging only.

; Allows calling OPcache API functions only from PHP scripts which path is
; started from specified string. The default "" means no restriction

; Mapping base of shared memory segments (for Windows only). All the PHP
; processes have to map shared memory into the same address space. This
; directive allows to manually fix the "Unable to reattach to base address"
; errors.

; Enables and sets the second level cache directory.
; It should improve performance when SHM memory is full, at server restart or
; SHM reset. The default "" disables file based caching.

; Enables or disables opcode caching in shared memory.

; Enables or disables checksum validation when script loaded from file cache.

; Implies opcache.file_cache_only=1 for a certain process that failed to
; reattach to the shared memory (for Windows only). Explicitly enabled file
; cache is required.

; Enables or disables copying of PHP code (text segment) into HUGE PAGES.
; This should improve performance, but requires appropriate OS configuration.

; Validate cached file permissions.
; opcache.validate_permission=0

; Prevent name collisions in chroot'ed environment.
; opcache.validate_root=0