PHP 8.4 doesn’t reserve huge pages on startup

[nisbet-hubbard]

Description

The following config:

opcache.huge_code_pages=1

Resulted in this output:

# PHP 8.4.12
$ rg -N Huge /proc/meminfo
AnonHugePages:         0 kB
ShmemHugePages:        0 kB
FileHugePages:         0 kB
HugePages_Total:     134
HugePages_Free:       70
HugePages_Rsvd:        5
HugePages_Surp:        0
Hugepagesize:       2048 kB
Hugetlb:          274432 kB

(The 5 were reserved by mysql.)

But I expected this output instead:

# PHP 8.3.22
$ rg -N Huge /proc/meminfo
AnonHugePages:         0 kB
ShmemHugePages:        0 kB
FileHugePages:         0 kB
HugePages_Total:     134
HugePages_Free:       67
HugePages_Rsvd:       66
HugePages_Surp:        0
Hugepagesize:       2048 kB
Hugetlb:          274432 kB

Is this a bug or a behaviour change with 8.4?

PHP Version

PHP 8.4.12 (cli) (built: Aug 29 2025 21:57:30) (NTS)                                                            
Copyright (c) The PHP Group                                                                                     
Zend Engine v4.4.12, Copyright (c) Zend Technologies                                                            
    with Zend OPcache v8.4.12, Copyright (c), by Zend Technologies

Operating System

AlmaLinux 10.0

[nisbet-hubbard]

I can confirm this has been fixed by #19388 and 0ee7732.