tune(litespeed): bump opcache 32→64 MB / 4000→8000 files + add per-site override

32M/4000 was too aggressive for heavy WP+Divi+WC sites: 3000+4000 unique
PHP files each blow through max_accelerated_files, causing constant
eviction + recompilation thrash. Manifested 2026-06-03 as ~40% sustained
CPU on alphaoneaminos and 5378 oom_kills/9h on brain-jar.

64M/8000 fits Divi + WC + WP core bytecode without eviction. N lsphp ×
64 MB ≈ 512 MiB shmem worst case — still under the per-instance setUIDMode
fan-out from the original 128M problem (which was 1+ GiB).

Per-site override (OPCACHE_MEMORY_MB / OPCACHE_MAX_FILES env vars) lets the
panel push down for low-traffic sites or up for outliers without rebuilding
the image. WHP panel UI ships in a follow-up commit.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

configs/litespeed/lsphp-overrides.ini

@@ -25,14 +25,26 @@ session.gc_divisor = 1000
 session.gc_maxlifetime = 1440
 
 opcache.enable = 1
-; Sized small because shmem is per-process-RSS on Linux cgroups (vs PHP-FPM's
-; COW-shared model). At 128 MB × N lsphp instances we were hitting 800+ MiB
-; shmem on heavy WP sites; 32 MB × N fits comfortably and still caches ~4000
-; scripts (covering Divi + WC + WP core easily). Bump per-site via WHP user
-; variables (OPCACHE_MEMORY_MB) if a high-traffic site needs more.
-opcache.memory_consumption = 32
-opcache.interned_strings_buffer = 8
-opcache.max_accelerated_files = 4000
+; Sized to fit Divi + WooCommerce + WP core comfortably without eviction
+; thrash. Per-instance because shmem is per-process-RSS on Linux cgroups
+; (vs PHP-FPM's COW-shared model — one lsphp PARENT per httpd worker in
+; OLS, each with its own opcache segment).
+;
+; Sizing history:
+;   128 MB / 10000 files (original): blew 800+ MiB shmem under setUIDMode 2
+;     because that gave 8+ lsphp instances each at 128 MB → 1+ GiB shmem.
+;   32 MB / 4000 files (2026-06-02): solved the shmem problem but caused
+;     opcache eviction thrash on Divi/WC sites (3000+4000 unique PHP files
+;     each); manifested as ~40% sustained CPU on alphaoneaminos and
+;     elevated OOM cycling on brain-jar (5378 oom_kills/9h on 2026-06-03).
+;   64 MB / 8000 files (current): fits Divi+WC bytecode without eviction;
+;     N lsphp × 64 MB ≈ 512 MiB shmem worst case, still acceptable.
+;
+; Override per-site via OPCACHE_MEMORY_MB / OPCACHE_MAX_FILES env vars
+; (panel: Advanced Tuning → OpCache size) for outliers.
+opcache.memory_consumption = 64
+opcache.interned_strings_buffer = 16
+opcache.max_accelerated_files = 8000
 opcache.revalidate_freq = 60
 opcache.enable_cli = Off
 

scripts/entrypoint-litespeed.sh

@@ -74,6 +74,19 @@ if [ -n "$SCAN_DIR" ]; then
 error_log = /home/${user}/logs/php-fpm/error.log
 log_errors = On
 EOF
+
+  ## Per-site opcache override (panel: Advanced Tuning → OpCache size).
+  ## Falls back to the global lsphp-overrides.ini values (64 MB / 8000 files)
+  ## when the env vars aren't set. Numeric range/sanity is enforced in the
+  ## WHP panel before the env var lands here.
+  if [ -n "${OPCACHE_MEMORY_MB:-}" ] || [ -n "${OPCACHE_MAX_FILES:-}" ]; then
+    {
+      echo "; rendered at container start by entrypoint-litespeed.sh"
+      echo "; per-site override from WHP whp.sites.opcache_*_override"
+      [ -n "${OPCACHE_MEMORY_MB:-}" ] && echo "opcache.memory_consumption = ${OPCACHE_MEMORY_MB}"
+      [ -n "${OPCACHE_MAX_FILES:-}" ]  && echo "opcache.max_accelerated_files = ${OPCACHE_MAX_FILES}"
+    } > "$SCAN_DIR/99-user-opcache.ini"
+  fi
 fi
 
 ## ---- ownership: OLS runs as $user end-to-end (server-level user set by