OS Benchmarking Workspace PR

scripts/os_benchmark_scripts/stress_combo_test.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+OUTFILE="stress_combo_$(date +%Y%m%d_%H%M%S).csv"
+DURATION=60
+
+echo "timestamp,cpu_load,temp_c,used_mem_mb" > "$OUTFILE"
+
+stress-ng --cpu 2 --io 1 --vm 1 --timeout "$DURATION" &
+
+PID=$!
+
+while kill -0 $PID 2>/dev/null; do
+    LOAD=$(awk '{print $1}' /proc/loadavg)
+    TEMP=$(vcgencmd measure_temp 2>/dev/null | grep -oP '[0-9.]+')
+    USED=$(free -m | awk '/Mem:/ {print $3}')
+    echo "$(date +%s),$LOAD,${TEMP:-N/A},$USED" >> "$OUTFILE"
+    sleep 2
+done
+
+echo "Combined stress test complete. Data saved to $OUTFILE"

scripts/os_benchmark_scripts/stress_cpu_test.sh

@@ -0,0 +1,202 @@
+#!/usr/bin/env bash
+
+# Context-switch focused OS behavior test using stress-ng
+# - Drives context switching with the 'switch' stressor
+# - Samples system-wide context switch rate from /proc/stat
+# - Captures procs_running and procs_blocked as scheduling signals
+# - Saves a time-series CSV and parses stress-ng metrics into a JSON summary
+
+set -euo pipefail
+
+# --- Config (env-overridable) ---
+DURATION="${DURATION:-60}"           # seconds to run the stressor
+WORKERS_DEFAULT=$(command -v nproc >/dev/null 2>&1 && nproc || echo 1)
+# Accept WORKERS, or fall back to legacy CORES env for convenience
+WORKERS="${WORKERS:-${CORES:-$WORKERS_DEFAULT}}"
+SAMPLE="${SAMPLE:-1}"               # sampling interval in seconds
+OUT_DIR="${OUT_DIR:-.}"
+
+# --- Preconditions ---
+if ! command -v stress-ng >/dev/null 2>&1; then
+    echo "Error: stress-ng is not installed or not in PATH." >&2
+    echo "On Debian/Ubuntu/Raspberry Pi OS: sudo apt-get update && sudo apt-get install -y stress-ng" >&2
+    exit 127
+fi
+
+if ! [[ "$DURATION" =~ ^[0-9]+$ ]] || ! [[ "$WORKERS" =~ ^[0-9]+$ ]] || ! [[ "$SAMPLE" =~ ^[0-9]+$ ]]; then
+    echo "Error: DURATION, WORKERS, and SAMPLE must be positive integers." >&2
+    exit 2
+fi
+
+mkdir -p "$OUT_DIR"
+START_TS_EPOCH=$(date +%s)
+TS=$(date +%Y%m%d_%H%M%S)
+CSV_FILE="$OUT_DIR/switch_ctx_${TS}.csv"
+LOG_FILE="$OUT_DIR/switch_ctx_stressng_${TS}.log"
+SUMMARY_FILE="$OUT_DIR/switch_ctx_summary_${TS}.json"
+
+echo "Starting context-switch test: duration=${DURATION}s, workers=${WORKERS}, sample=${SAMPLE}s"
+
+# --- CSV header ---
+echo "timestamp,ctxt_per_s,procs_running,procs_blocked,ctxt_total,interval_s" > "$CSV_FILE"
+
+# Helper: read total context switches from /proc/stat
+get_ctxt_total() {
+    awk '/^ctxt /{print $2}' /proc/stat
+}
+
+# Helper: read procs_running and procs_blocked from /proc/stat
+get_procs_signals() {
+    awk '/^procs_running /{pr=$2} /^procs_blocked /{pb=$2} END{print pr,pb}' /proc/stat
+}
+
+# Initialize sampling baselines
+prev_ctxt=$(get_ctxt_total)
+prev_ts=$(date +%s)
+
+# --- Run stress-ng in the background with logging ---
+# Using --log-file to reliably capture metrics-brief output in LOG_FILE
+set +e
+stress-ng \
+    --switch "$WORKERS" \
+    --timeout "$DURATION" \
+    --metrics-brief \
+    --times \
+    --log-file "$LOG_FILE" &
+PID=$!
+set -e
+
+# --- Sampling loop ---
+sample_count=0
+sum_rate=0
+max_rate=0
+max_procs_running=0
+max_procs_blocked=0
+
+while kill -0 "$PID" 2>/dev/null; do
+    sleep "$SAMPLE"
+    now_ts=$(date +%s)
+    now_ctxt=$(get_ctxt_total)
+    interval=$(( now_ts - prev_ts ))
+    if (( interval <= 0 )); then
+        continue
+    fi
+    delta=$(( now_ctxt - prev_ctxt ))
+    # Compute per-second rate with two decimal precision
+    rate=$(awk -v d="$delta" -v i="$interval" 'BEGIN{ if(i>0){ printf("%.2f", d/i) } else { printf("0.00") } }')
+    read -r procs_running procs_blocked < <(get_procs_signals)
+
+    # Append to CSV
+    echo "${now_ts},${rate},${procs_running},${procs_blocked},${now_ctxt},${interval}" >> "$CSV_FILE"
+
+    # Update accumulators
+    sample_count=$(( sample_count + 1 ))
+    # sum_rate as integer*100 to avoid floating math issues; scale by 100
+    rate_int=$(awk -v r="$rate" 'BEGIN{ printf("%d", r*100) }')
+    sum_rate=$(( sum_rate + rate_int ))
+
+    # Track max rate (string compare is tricky; compare as integers with scale*100)
+    if (( rate_int > max_rate )); then
+        max_rate=$rate_int
+    fi
+
+    if (( procs_running > max_procs_running )); then
+        max_procs_running=$(( procs_running ))
+    fi
+    if (( procs_blocked > max_procs_blocked )); then
+        max_procs_blocked=$(( procs_blocked ))
+    fi
+
+    # Shift baseline
+    prev_ctxt=$now_ctxt
+    prev_ts=$now_ts
+done
+
+wait "$PID" || true
+END_TS_EPOCH=$(date +%s)
+
+# --- Parse stress-ng metrics from LOG_FILE ---
+# Try to find the last data line for the 'switch' stressor. The fields typically are:
+# stressor  bogo ops  real time  usr time  sys time  bogo ops/s
+switch_line=$(grep -E "[[:space:]]switch[[:space:]]+[0-9]" "$LOG_FILE" | tail -n 1 || true)
+
+bogo_ops=""
+real_time_s=""
+user_time_s=""
+sys_time_s=""
+bogo_ops_per_s=""
+
+if [[ -n "$switch_line" ]]; then
+    # Extract fields after the token 'switch'
+    # This is robust to leading 'stress-ng: info: [pid]' prefixes
+    read -r bogo_ops real_t user_t sys_t bos <<EOF
+$(awk '{
+    s=0; for(i=1;i<=NF;i++){ if($i=="switch"){ s=i; break } }
+    if(s>0){
+        # Handle both with and without trailing s in times (e.g., 10.00 or 10.00s)
+        rt=$(s+1); gsub(/s$/,"",rt);
+        ut=$(s+2); gsub(/s$/,"",ut);
+        st=$(s+3); gsub(/s$/,"",st);
+        bos=$(s+4);
+        print $(s+1),rt,ut,st,bos;
+    }
+}' <<< "$switch_line")
+EOF
+    bogo_ops="$bogo_ops"
+    real_time_s="$real_t"
+    user_time_s="$user_t"
+    sys_time_s="$sys_t"
+    bogo_ops_per_s="$bos"
+fi
+
+# Compute averages
+avg_rate="0.00"
+max_rate_float="0.00"
+if (( sample_count > 0 )); then
+    avg_rate=$(awk -v s="$sum_rate" -v n="$sample_count" 'BEGIN{ printf("%.2f", (s/100)/n) }')
+    max_rate_float=$(awk -v m="$max_rate" 'BEGIN{ printf("%.2f", m/100) }')
+fi
+
+# --- Summary JSON ---
+uname_str=$(uname -a || true)
+start_iso=$(date -u -d @${START_TS_EPOCH} +%Y-%m-%dT%H:%M:%SZ)
+end_iso=$(date -u -d @${END_TS_EPOCH} +%Y-%m-%dT%H:%M:%SZ)
+
+cat > "$SUMMARY_FILE" <<JSON
+{
+    "test": "context-switch",
+    "start_time": "${start_iso}",
+    "end_time": "${end_iso}",
+    "duration_s": ${DURATION},
+    "workers": ${WORKERS},
+    "sample_interval_s": ${SAMPLE},
+    "artifacts": {
+        "time_series_csv": "${CSV_FILE}",
+        "stressng_log": "${LOG_FILE}"
+    },
+    "system": {
+        "uname": "${uname_str}" 
+    },
+    "stats": {
+        "samples": ${sample_count},
+        "avg_ctxt_per_s": ${avg_rate},
+        "max_ctxt_per_s": ${max_rate_float},
+        "max_procs_running": ${max_procs_running},
+        "max_procs_blocked": ${max_procs_blocked}
+    },
+    "stress_ng": {
+        "stressor": "switch",
+        "bogo_ops": ${bogo_ops:-0},
+        "bogo_ops_per_s": ${bogo_ops_per_s:-0},
+        "real_time_s": ${real_time_s:-0},
+        "user_time_s": ${user_time_s:-0},
+        "sys_time_s": ${sys_time_s:-0}
+    }
+}
+JSON
+
+echo "Context-switch test complete."
+echo "- CSV:     $CSV_FILE"
+echo "- Log:     $LOG_FILE"
+echo "- Summary: $SUMMARY_FILE"
+