【Rocky Linux 9】10.OPcache設定（PHP）

## OPcache設定
PHP8ではJIT（Just-In-Time）と呼ばれる、プログラムコードをネイティブコードにする機能が有効になっている。
このネイティブコードをOPcacheにてキャッシュさせることで高速化する。

### OPcacheインストール
PHPインストール時にインストールされているはずだが、インストールされていない場合は明示的にインストールする
```shell-session
dnf install php-opcache
```

### OPcache設定
基本的にはデフォルトのままで問題無い。
```shell-session:/etc/php.d/10-opcache.ini
; Enable Zend OPcache extension module
zend_extension=opcache

; Determines if Zend OPCache is enabled
opcache.enable=1

; Determines if Zend OPCache is enabled for the CLI version of PHP
opcache.enable_cli=1

; The OPcache shared memory storage size.
;opcache.memory_consumption=128

; The amount of memory for interned strings in Mbytes.
;opcache.interned_strings_buffer=8

; The maximum number of keys (scripts) in the OPcache hash table.
; Only numbers between 200 and 1000000 are allowed.
;opcache.max_accelerated_files=10000

; The maximum percentage of "wasted" memory until a restart is scheduled.
;opcache.max_wasted_percentage=5

; 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.
;opcache.use_cwd=1

; When disabled, you must reset the OPcache manually or restart the
; webserver for changes to the filesystem to take effect.
;opcache.validate_timestamps=1

; 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)
;opcache.revalidate_freq=2

; Enables or disables file search in include_path optimization
;opcache.revalidate_path=0

; If disabled, all PHPDoc comments are dropped from the code to reduce the
; size of the optimized code.
;opcache.save_comments=1

; If enabled, compilation warnings (including notices and deprecations) will
; be recorded and replayed each time a file is included. Otherwise, compilation
; warnings will only be emitted when the file is first cached.
;opcache.record_warnings=0

; Allow file existence override (file_exists, etc.) performance feature.
;opcache.enable_file_override=0

; A bitmask, where each bit enables or disables the appropriate OPcache
; passes
;opcache.optimization_level=0x7FFFBFFF

; This hack should only be enabled to work around "Cannot redeclare class"
; errors.
;opcache.dups_fix=0

; 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.
opcache.blacklist_filename=/etc/php.d/opcache*.blacklist

; Allows exclusion of large files from being cached. By default all files
; are cached.
;opcache.max_file_size=0

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

; How long to wait (in seconds) for a scheduled restart to begin if the cache
; is not being accessed.
;opcache.force_restart_timeout=180

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

; 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).
;opcache.log_verbosity_level=1

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

; Protect the shared memory from unexpected writing during script execution.
; Useful for internal debugging only.
;opcache.protect_memory=0

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

; 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.
; RPM note : file cache directory must be owned by process owner
;   for mod_php, see /etc/httpd/conf.d/php.conf
;   for php-fpm, see /etc/php-fpm.d/*conf
;opcache.file_cache=

; Enables or disables opcode caching in shared memory.
;opcache.file_cache_only=0

; Enables or disables checksum validation when script loaded from file cache.
;opcache.file_cache_consistency_checks=1

; 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.file_cache_fallback=1

; Enables or disables copying of PHP code (text segment) into HUGE PAGES.
; This should improve performance, but requires appropriate OS configuration.
opcache.huge_code_pages=0

; Validate cached file permissions.
; Leads OPcache to check file readability on each access to cached file.
; This directive should be enabled in shared hosting environment, when few
; users (PHP-FPM pools) reuse the common OPcache shared memory.
;opcache.validate_permission=0

; Prevent name collisions in chroot'ed environment.
; This directive prevents file name collisions in different "chroot"
; environments. It should be enabled for sites that may serve requests in
; different "chroot" environments.
;opcache.validate_root=0

; If specified, it produces opcode dumps for debugging different stages of
; optimizations.
;opcache.opt_debug_level=0

; Specifies a PHP script that is going to be compiled and executed at server
; start-up.
; http://php.net/opcache.preload
;opcache.preload=

; Preloading code as root is not allowed for security reasons. This directive
; facilitates to let the preloading to be run as another user.
; http://php.net/opcache.preload_user
;opcache.preload_user=

; Prevents caching files that are less than this number of seconds old. It
; protects from caching of incompletely updated files. In case all file updates
; on your site are atomic, you may increase performance by setting it to "0".
;opcache.file_update_protection=2

; Absolute path used to store shared lockfiles (for *nix only).
;opcache.lockfile_path=/tmp

opcache.jit=on
opcache.jit_buffer_size=128M
```

### PHP-FPM再起動
```shell-session
systemctl restart php-fpm
```

### OPcache動作状況確認
OPcache Control Panelを利用する。
（ck-on / ocp.php：https://gist.github.com/ck-on/4959032）