Add hugepages_diag.sh

Author: daedalus

sysadmin/hugepages_diag.sh

@@ -0,0 +1,82 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+echo "=== HugePages Diagnostic ==="
+echo
+
+echo "[1] /proc/meminfo"
+grep -i huge /proc/meminfo || echo "No hugepage-related fields found"
+echo
+
+echo "[2] Static hugepage reservation"
+if [[ -r /proc/sys/vm/nr_hugepages ]]; then
+    echo -n "nr_hugepages: "
+    cat /proc/sys/vm/nr_hugepages
+else
+    echo "Cannot read /proc/sys/vm/nr_hugepages"
+fi
+echo
+
+echo "[3] Transparent Huge Pages (THP)"
+THP_BASE="/sys/kernel/mm/transparent_hugepage"
+if [[ -r "$THP_BASE/enabled" ]]; then
+    echo -n "enabled: "
+    cat "$THP_BASE/enabled"
+else
+    echo "THP status file not found"
+fi
+
+if [[ -r "$THP_BASE/defrag" ]]; then
+    echo -n "defrag:  "
+    cat "$THP_BASE/defrag"
+fi
+echo
+
+echo "[4] CPU support flags"
+CPU_FLAGS=$(grep -m1 '^flags' /proc/cpuinfo || true)
+
+if echo "$CPU_FLAGS" | grep -qw pse; then
+    echo "2 MB hugepages supported (pse)"
+else
+    echo "2 MB hugepages flag NOT found"
+fi
+
+if echo "$CPU_FLAGS" | grep -qw pdpe1gb; then
+    echo "1 GB hugepages supported (pdpe1gb)"
+else
+    echo "1 GB hugepages flag NOT found"
+fi
+echo
+
+echo "[5] Per-size hugepage pools"
+HP_DIR="/sys/kernel/mm/hugepages"
+if [[ -d "$HP_DIR" ]]; then
+    for d in "$HP_DIR"/hugepages-*; do
+        [[ -d "$d" ]] || continue
+        size=$(basename "$d")
+        free=$(cat "$d/free_hugepages" 2>/dev/null || echo "?")
+        total=$(cat "$d/nr_hugepages" 2>/dev/null || echo "?")
+        reserved=$(cat "$d/resv_hugepages" 2>/dev/null || echo "?")
+        echo "$size -> total=$total free=$free reserved=$reserved"
+    done
+else
+    echo "Hugepage sysfs directory not found"
+fi
+echo
+
+echo "[6] Quick verdict"
+TOTAL=$(grep '^HugePages_Total:' /proc/meminfo 2>/dev/null | awk '{print $2}')
+THP=$(cat /sys/kernel/mm/transparent_hugepage/enabled 2>/dev/null || true)
+
+if [[ "${TOTAL:-0}" -gt 0 ]]; then
+    echo "Explicit hugepages AVAILABLE"
+else
+    echo "Explicit hugepages NOT reserved"
+fi
+
+if echo "$THP" | grep -q '\['; then
+    ACTIVE=$(echo "$THP" | grep -o '\[[^]]*\]' | tr -d '[]')
+    echo "THP active mode: $ACTIVE"
+else
+    echo "THP status unknown"
+fi