Here's a short explanation of
the configuration directives.
 
 
   
    - 
     opcache.enableboolean
- 
     
      Enables the opcode cache. When disabled, code is not optimised or 
      cached. The setting opcache.enable can not be
      enabled at runtime through ini_set, it can only
      be disabled. Trying to enable it at in a script will generate a warning.
      
- 
     opcache.enable_cliboolean
- 
     
      Enables the opcode cache for the CLI version of PHP.
      
- 
     opcache.memory_consumptioninteger
- 
     
      The size of the shared memory storage used by OPcache, in megabytes.
      
- 
     opcache.interned_strings_bufferinteger
- 
     
      The amount of memory used to store interned strings, in megabytes. This
      configuration directive is ignored in PHP < 5.3.0.
      
- 
     opcache.max_accelerated_filesinteger
- 
     
      The maximum number of keys (and therefore scripts) in the OPcache hash
      table. The actual value used will be the first number in the set of
      prime numbers
      { 223, 463, 983, 1979, 3907, 7963, 16229, 32531, 65407, 130987 }
      that is greater than or equal to the configured value. The minimum value is 200. The maximum
      value is 100000 in PHP < 5.5.6, and 1000000 in later versions.
      
- 
     opcache.max_wasted_percentageinteger
- 
     
      The maximum percentage of wasted memory that is allowed before a restart
      is scheduled.
      
- 
     opcache.use_cwdboolean
- 
     
      If enabled, OPcache appends the current working directory to the script
      key, thereby eliminating possible collisions between files with the same
      base name. Disabling this directive improves performance, but may break
      existing applications.
      
- 
     opcache.validate_timestampsboolean
- 
     
      If enabled, OPcache will check for updated scripts every
      opcache.revalidate_freq
      seconds. When this directive is disabled, you must reset OPcache
      manually via opcache_reset,
      opcache_invalidate or by restarting the Web server
      for changes to the filesystem to take effect.
      
- 
     opcache.revalidate_freqinteger
- 
     
      How often to check script timestamps for updates, in seconds.
      0 will result in OPcache checking for updates on
      every request.
      
      This configuration directive is ignored if
      opcache.validate_timestamps
      is disabled.
      
- 
     opcache.revalidate_pathboolean
- 
     
      If disabled, existing cached files using the same
      include_path will be reused.
      Thus, if a file with the same name is elsewhere in the include_path, it
      won't be found.
      
- 
     
      If disabled, all documentation comments will be discarded from the
      opcode cache to reduce the size of the optimised code. Disabling this
      configuration directive may break applications and frameworks that rely
      on comment parsing for annotations, including Doctrine, Zend Framework 2
      and PHPUnit.
      
- 
     
      If disabled, documentation comments won't be loaded from the opcode
      cache even if they exist. This can be used with
      opcache.save_comments
      to only load comments for applications that require them.
      
- 
     opcache.fast_shutdownboolean
- 
     
      If enabled, a fast shutdown sequence is used that doesn't free each
      allocated block, but relies on the Zend Engine memory manager to
      deallocate the entire set of request variables en masse.
      
- 
     opcache.enable_file_overrideboolean
- 
     
      When enabled, the opcode cache will be checked for whether a file has
      already been cached when file_exists,
      is_file and is_readable are
      called. This may increase performance in applications that check the
      existence and readability of PHP scripts, but risks returning stale data
      if 
      opcache.validate_timestamps
      is disabled.
      
- 
     opcache.optimization_levelinteger
- 
     
      A bitmask that controls which optimisation passes are executed.
      
- 
     opcache.inherited_hackboolean
- 
     
      In PHP < 5.3, OPcache stores the places where
      DECLARE_CLASS
      opcodes used inheritance; when the file is loaded, OPcache then tries to
      bind the inherited classes using the current environment. The problem is
      that while the DECLARE_CLASS opcode may not be needed for the current
      script, if the script requires that the opcode be defined, it may not
      run.
      
      This configuration directive is ignored in PHP 5.3 and later.
      
- 
     opcache.dups_fixboolean
- 
     
      This hack should only be enabled to work around "Cannot redeclare class"
      errors.
      
- 
     opcache.blacklist_filenamestring
- 
     
      The location of the OPcache blacklist file. A blacklist file is a text
      file containing the names of files that should not be accelerated, one
      per line. Wildcards are allowed, and prefixes can also be provided.
      Lines starting with a semi-colon are ignored as comments.
      
      A simple blacklist file might look as follows:
      
- 
     opcache.max_file_sizeinteger
- 
     
      The maximum file size that will be cached, in bytes. If this is
      0, all files will be cached.
      
- 
     opcache.consistency_checksinteger
- 
     
      If non-zero, OPcache will verify the cache checksum every N requests,
      where N is the value of this configuration directive. This should only
      be enabled when debugging, as it will impair performance.
      
- 
     opcache.force_restart_timeoutinteger
- 
     
      The length of time to wait for a scheduled restart to begin if the cache
      isn't active, in seconds. If the timeout is hit, then OPcache assumes
      that something is wrong and will kill the processes holding locks on the
      cache to permit a restart.
      
      If
      opcache.log_verbosity_level
      is set to 2 or above, a warning will be recorded in the error log when
      this occurs.
      
- 
     opcache.error_logstring
- 
     
      The error log for OPcache errors. An empty string is treated the same as
      stderr, and will result in logs being sent to
      standard error (which will be the Web server error log in most cases).
      
- 
     opcache.log_verbosity_levelinteger
- 
     
      The log verbosity level. By default, only fatal errors (level 0) and
      errors (level 1) are logged. Other levels available are warnings (level
      2), information messages (level 3) and debug messages (level 4).
      
- 
     opcache.preferred_memory_modelstring
- 
     
      The preferred memory model for OPcache to use. If left empty, OPcache
      will choose the most appropriate model, which is the correct behaviour
      in virtually all cases.
      
      Possible values include mmap, shm,
      posix and win32.
      
- 
     opcache.protect_memoryboolean
- 
     
      Protects shared memory from unexpected writes while executing scripts.
      This is useful for internal debugging only.
      
- 
     opcache.mmap_basestring
- 
     
      The base used for shared memory segments on Windows. All PHP processes
      have to map shared memory into the same address space. Using this
      directive allows "Unable to reattach to base address" errors to be
      fixed.
      
- 
     opcache.restrict_apistring
- 
     
      Allows calling OPcache API functions only from PHP scripts which path
      is started from specified string. The default "" means no restriction.
      
- 
     opcache.file_cachestring
- 
     
      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.
      
- 
     opcache.file_cache_onlyboolean
- 
     
      Enables or disables opcode caching in shared memory.
      
- 
     opcache.file_cache_consistency_checksboolean
- 
     
      Enables or disables checksum validation when script loaded from file cache.
      
- 
     opcache.file_cache_fallbackboolean
- 
     
      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.
      
- 
     opcache.validate_permissionboolean
- 
     
      Validates the cached file permissions against the current user.
      
- 
     opcache.validate_rootboolean
- 
     
      Prevents name collisions in chroot'ed environments. This should be enabled in
      all chroot'ed environments to prevent access to files outside the chroot.