opcache used_memory reports negative value

<?php
                var_dump(opcache_get_status()['memory_usage']);
?>

Reports a negative value for used_memory.

Image is from a VDS system with opcache.memory_consumption=1GB and several sites.

But issue was reproduced within the following environment:

PHP 8.3
shared hosting server with PHP-FPM
two sites with individual opcache.memory_consumption settings
first site: 128M
second site: 256M
global settings in plesk: 256M

Second site reports correct values, but first site, with lower settings reports negative value for "used_memory"

Changing both sites to dedicated PHP-FPM fixes the issue, but in the default config it fails.

C.

You probably meant to submit this as bug report, not as documentation issue. Transferring.

I'm seeing similar values on 8.5 (FrankenPHP) and a few more broken ones.

Also, opcache_get_configuration reports 0 for "opcache.memory_consumption", but that value should be 256MB (and according to ini_get_all is).

`opcache_get_status();`

array (
  'opcache_enabled' => true,
  'cache_full' => false,
  'restart_pending' => false,
  'restart_in_progress' => false,
  'memory_usage' => 
  array (
    'used_memory' => -219550752,
    'free_memory' => 218927256,
    'wasted_memory' => 623496,
    'current_wasted_percentage' => INF,
  ),
  'interned_strings_usage' => 
  array (
    'buffer_size' => 16777216,
    'used_memory' => 10241152,
    'free_memory' => 6536064,
    'number_of_strings' => 76914,
  ),
  'opcache_statistics' => 
  array (
    'num_cached_scripts' => 1365,
    'num_cached_keys' => 1993,
    'max_cached_keys' => 32531,
    'hits' => 20153,
    'start_time' => 1769432071,
    'last_restart_time' => 0,
    'oom_restarts' => 0,
    'hash_restarts' => 0,
    'manual_restarts' => 0,
    'misses' => 1381,
    'blacklist_misses' => 0,
    'blacklist_miss_ratio' => 0.0,
    'opcache_hit_rate' => 93.58688585492709,
  ),
  'scripts' => 
  array (
    ...
  ),
  'jit' => 
  array (
    'enabled' => false,
    'on' => false,
    'kind' => 0,
    'opt_level' => 0,
    'opt_flags' => 0,
    'buffer_size' => 0,
    'buffer_free' => 0,
  ),
)

`opcache_get_configuration();`

array (
  'directives' => 
  array (
    'opcache.enable' => true,
    'opcache.enable_cli' => false,
    'opcache.use_cwd' => true,
    'opcache.validate_timestamps' => true,
    'opcache.validate_permission' => false,
    'opcache.validate_root' => false,
    'opcache.dups_fix' => false,
    'opcache.revalidate_path' => false,
    'opcache.log_verbosity_level' => 1,
    'opcache.memory_consumption' => 0,
    'opcache.interned_strings_buffer' => 16,
    'opcache.max_accelerated_files' => 32531,
    'opcache.max_wasted_percentage' => 0.05,
    'opcache.force_restart_timeout' => 180,
    'opcache.revalidate_freq' => 2,
    'opcache.preferred_memory_model' => '',
    'opcache.blacklist_filename' => '',
    'opcache.max_file_size' => 0,
    'opcache.error_log' => '',
    'opcache.protect_memory' => false,
    'opcache.save_comments' => true,
    'opcache.record_warnings' => false,
    'opcache.enable_file_override' => true,
    'opcache.optimization_level' => 0,
    'opcache.lockfile_path' => '/tmp',
    'opcache.file_cache' => '',
    'opcache.file_cache_read_only' => false,
    'opcache.file_cache_only' => false,
    'opcache.file_cache_consistency_checks' => true,
    'opcache.file_update_protection' => 2,
    'opcache.opt_debug_level' => 0,
    'opcache.restrict_api' => '',
    'opcache.huge_code_pages' => false,
    'opcache.preload' => '',
    'opcache.preload_user' => '',
    'opcache.jit' => 'disable',
    'opcache.jit_buffer_size' => 67108864,
    'opcache.jit_debug' => 0,
    'opcache.jit_bisect_limit' => 0,
    'opcache.jit_blacklist_root_trace' => 16,
    'opcache.jit_blacklist_side_trace' => 8,
    'opcache.jit_hot_func' => 127,
    'opcache.jit_hot_loop' => 61,
    'opcache.jit_hot_return' => 8,
    'opcache.jit_hot_side_exit' => 8,
    'opcache.jit_max_exit_counters' => 8192,
    'opcache.jit_max_loop_unrolls' => 8,
    'opcache.jit_max_polymorphic_calls' => 2,
    'opcache.jit_max_recursive_calls' => 2,
    'opcache.jit_max_recursive_returns' => 2,
    'opcache.jit_max_root_traces' => 1024,
    'opcache.jit_max_side_traces' => 128,
    'opcache.jit_prof_threshold' => 0.005,
    'opcache.jit_max_trace_length' => 1024,
  ),
  'version' => 
  array (
    'version' => '8.5.2',
    'opcache_product_name' => 'Zend OPcache',
  ),
  'blacklist' => 
  array (
  ),
)

Adjust memory usage calculation for PHP 8.0.5+ in OPcache status (php…

I have the same issue with FrankenPHP v1.11.3 PHP 8.5.4 on debian trixie. and that make some app to crash because of DivisionByZeroError

Just wanted to add a +1. We are using PHP with a custom SAPI integration in ZTS. It happens on Windows and Linux.

I'm going to say that this is fixed now (commits a2d8ee2 and 4eac7a3), but if you still see this problem in 8.5.13, please raise a new GH issue. This is unlikely to be backported to PHP 8.4.

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opcache used_memory reports negative value #16927

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opcache used_memory reports negative value #16927

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cmb69 commented on Nov 24, 2024

aleho commented on Jan 26, 2026

GreyXor commented on Mar 3, 2026

paresy commented on May 30, 2026

kamil-tekiela commented on Nov 10, 2026

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