[PATCH 4/4] testing: add dontcache-bench local filesystem benchmark suite

Jeff Layton
2026-04-01T19:11:30Z

Add a benchmark suite for testing IOCB_DONTCACHE on local filesystems
via fio's io_uring engine with the RWF_DONTCACHE flag.

The suite mirrors the nfsd-io-bench test matrix but uses io_uring with
the "uncached" fio option instead of NFSD debugfs mode switching:
- uncached=0: standard buffered I/O
- uncached=1: RWF_DONTCACHE
- Mode 2 uses O_DIRECT via fio's --direct=1

Includes fio job files, run-benchmarks.sh, and parse-results.sh.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
.../dontcache-bench/fio-jobs/lat-reader.fio | 12 +
.../dontcache-bench/fio-jobs/multi-write.fio | 9 +
.../dontcache-bench/fio-jobs/noisy-writer.fio | 12 +
.../testing/dontcache-bench/fio-jobs/rand-read.fio | 13 +
.../dontcache-bench/fio-jobs/rand-write.fio | 13 +
.../testing/dontcache-bench/fio-jobs/seq-read.fio | 13 +
.../testing/dontcache-bench/fio-jobs/seq-write.fio | 13 +
.../dontcache-bench/scripts/parse-results.sh | 238 ++++++++++
.../dontcache-bench/scripts/run-benchmarks.sh | 518 +++++++++++++++++++++
9 files changed, 841 insertions(+)

diff --git a/tools/testing/dontcache-bench/fio-jobs/lat-reader.fio b/tools/testing/dontcache-bench/fio-jobs/lat-reader.fio
new file mode 100644
index 0000000000000000000000000000000000000000..e221e7aedec9d20953898d19dc44beb0588a2d6e
--- /dev/null
+++ b/tools/testing/dontcache-bench/fio-jobs/lat-reader.fio
@@ -0,0 +1,12 @@
+[global]
+ioengine=io_uring
+direct=0
+bs=4k
+numjobs=1
+time_based=0
+rw=read
+log_avg_msec=1000
+write_bw_log=latreader
+write_lat_log=latreader
+
+[latreader]
diff --git a/tools/testing/dontcache-bench/fio-jobs/multi-write.fio b/tools/testing/dontcache-bench/fio-jobs/multi-write.fio
new file mode 100644
index 0000000000000000000000000000000000000000..8fc0770f5860667249bef3553b9d9624eb0e2213
--- /dev/null
+++ b/tools/testing/dontcache-bench/fio-jobs/multi-write.fio
@@ -0,0 +1,9 @@
+[global]
+ioengine=io_uring
+direct=0
+bs=1M
+numjobs=1
+time_based=0
+rw=write
+
+[multiwrite]
diff --git a/tools/testing/dontcache-bench/fio-jobs/noisy-writer.fio b/tools/testing/dontcache-bench/fio-jobs/noisy-writer.fio
new file mode 100644
index 0000000000000000000000000000000000000000..4524eebd4642f292e0a6093319fc573b79820ff8
--- /dev/null
+++ b/tools/testing/dontcache-bench/fio-jobs/noisy-writer.fio
@@ -0,0 +1,12 @@
+[global]
+ioengine=io_uring
+direct=0
+bs=1M
+numjobs=1
+time_based=0
+rw=write
+log_avg_msec=1000
+write_bw_log=noisywriter
+write_lat_log=noisywriter
+
+[noisywriter]
diff --git a/tools/testing/dontcache-bench/fio-jobs/rand-read.fio b/tools/testing/dontcache-bench/fio-jobs/rand-read.fio
new file mode 100644
index 0000000000000000000000000000000000000000..e281fa82b86ad12ca4b2dc4fd082d62415dd967a
--- /dev/null
+++ b/tools/testing/dontcache-bench/fio-jobs/rand-read.fio
@@ -0,0 +1,13 @@
+[global]
+ioengine=io_uring
+direct=0
+bs=4k
+numjobs=1
+iodepth=16
+time_based=0
+rw=randread
+log_avg_msec=1000
+write_bw_log=randread
+write_lat_log=randread
+
+[randread]
diff --git a/tools/testing/dontcache-bench/fio-jobs/rand-write.fio b/tools/testing/dontcache-bench/fio-jobs/rand-write.fio
new file mode 100644
index 0000000000000000000000000000000000000000..cf53bc6f14b9e131793cdcdd4c431ec4e0b79dba
--- /dev/null
+++ b/tools/testing/dontcache-bench/fio-jobs/rand-write.fio
@@ -0,0 +1,13 @@
+[global]
+ioengine=io_uring
+direct=0
+bs=4k
+numjobs=1
+iodepth=16
+time_based=0
+rw=randwrite
+log_avg_msec=1000
+write_bw_log=randwrite
+write_lat_log=randwrite
+
+[randwrite]
diff --git a/tools/testing/dontcache-bench/fio-jobs/seq-read.fio b/tools/testing/dontcache-bench/fio-jobs/seq-read.fio
new file mode 100644
index 0000000000000000000000000000000000000000..ef87921465a7d8221dda0c6d01c0d4be14806703
--- /dev/null
+++ b/tools/testing/dontcache-bench/fio-jobs/seq-read.fio
@@ -0,0 +1,13 @@
+[global]
+ioengine=io_uring
+direct=0
+bs=1M
+numjobs=1
+iodepth=16
+time_based=0
+rw=read
+log_avg_msec=1000
+write_bw_log=seqread
+write_lat_log=seqread
+
+[seqread]
diff --git a/tools/testing/dontcache-bench/fio-jobs/seq-write.fio b/tools/testing/dontcache-bench/fio-jobs/seq-write.fio
new file mode 100644
index 0000000000000000000000000000000000000000..da3082f9b391e1112eb25756136e5b7f27d6b5e2
--- /dev/null
+++ b/tools/testing/dontcache-bench/fio-jobs/seq-write.fio
@@ -0,0 +1,13 @@
+[global]
+ioengine=io_uring
+direct=0
+bs=1M
+numjobs=1
+iodepth=16
+time_based=0
+rw=write
+log_avg_msec=1000
+write_bw_log=seqwrite
+write_lat_log=seqwrite
+
+[seqwrite]
diff --git a/tools/testing/dontcache-bench/scripts/parse-results.sh b/tools/testing/dontcache-bench/scripts/parse-results.sh
new file mode 100755
index 0000000000000000000000000000000000000000..0427d411db04903a5d9506751695d9452b011e6a
--- /dev/null
+++ b/tools/testing/dontcache-bench/scripts/parse-results.sh
@@ -0,0 +1,238 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Parse fio JSON output and generate comparison tables.
+#
+# Usage: ./parse-results.sh <results-dir>
+
+set -euo pipefail
+
+if [ $# -lt 1 ]; then
+ echo "Usage: $0 <results-dir>"
+ exit 1
+fi
+
+RESULTS_DIR="$1"
+
+if ! command -v jq &>/dev/null; then
+ echo "ERROR: jq is required"
+ exit 1
+fi
+
+# Extract metrics from a single fio JSON result
+extract_metrics() {
+ local json_file=$1
+ local rw_type=$2 # read or write
+
+ if [ ! -f "$json_file" ]; then
+ echo "N/A N/A N/A N/A N/A N/A"
+ return
+ fi
+
+ jq -r --arg rw "$rw_type" '
+ .jobs[0][$rw] as $d |
+ [
+ (($d.bw // 0) / 1024 | . * 10 | round / 10), # MB/s
+ ($d.iops // 0), # IOPS
+ ((($d.clat_ns.mean // 0) / 1000) | . * 10 | round / 10), # avg lat us
+ (($d.clat_ns.percentile["50.000000"] // 0) / 1000), # p50 us
+ (($d.clat_ns.percentile["99.000000"] // 0) / 1000), # p99 us
+ (($d.clat_ns.percentile["99.900000"] // 0) / 1000) # p99.9 us
+ ] | @tsv
+ ' "$json_file" 2>/dev/null || echo "N/A N/A N/A N/A N/A N/A"
+}
+
+# Extract server CPU from vmstat log (average sys%)
+extract_cpu() {
+ local vmstat_log=$1
+ if [ ! -f "$vmstat_log" ]; then
+ echo "N/A"
+ return
+ fi
+ # vmstat columns: us sy id wa st — skip header lines
+ awk 'NR>2 {sum+=$14; n++} END {if(n>0) printf "%.1f", sum/n; else print "N/A"}' \
+ "$vmstat_log" 2>/dev/null || echo "N/A"
+}
+
+# Extract peak dirty pages from meminfo log
+extract_peak_dirty() {
+ local meminfo_log=$1
+ if [ ! -f "$meminfo_log" ]; then
+ echo "N/A"
+ return
+ fi
+ grep "^Dirty:" "$meminfo_log" | awk '{print $2}' | sort -n | tail -1 || echo "N/A"
+}
+
+# Extract peak cached from meminfo log
+extract_peak_cached() {
+ local meminfo_log=$1
+ if [ ! -f "$meminfo_log" ]; then
+ echo "N/A"
+ return
+ fi
+ grep "^Cached:" "$meminfo_log" | awk '{print $2}' | sort -n | tail -1 || echo "N/A"
+}
+
+print_separator() {
+ printf '%*s\n' 120 '' | tr ' ' '-'
+}
+
+########################################################################
+# Deliverable 1: Single-client results
+########################################################################
+echo ""
+echo "=================================================================="
+echo " Deliverable 1: Single-Client fio Benchmarks"
+echo "=================================================================="
+echo ""
+
+for workload in seq-write rand-write seq-read rand-read; do
+ case $workload in
+ seq-write|rand-write) rw_type="write" ;;
+ seq-read|rand-read) rw_type="read" ;;
+ esac
+
+ echo "--- $workload ---"
+ printf "%-16s %10s %10s %10s %10s %10s %10s %10s %12s %12s\n" \
+ "Mode" "MB/s" "IOPS" "Avg(us)" "p50(us)" "p99(us)" "p99.9(us)" "Sys CPU%" "PeakDirty(kB)" "PeakCache(kB)"
+ print_separator
+
+ for mode in buffered dontcache direct; do
+ dir="${RESULTS_DIR}/${workload}/${mode}"
+ json_file=$(find "$dir" -name '*.json' -not -name 'client*' 2>/dev/null | head -1 || true)
+ if [ -z "$json_file" ]; then
+ printf "%-16s %10s\n" "$mode" "(no data)"
+ continue
+ fi
+
+ read -r mbps iops avg_lat p50 p99 p999 <<< \
+ "$(extract_metrics "$json_file" "$rw_type")"
+ cpu=$(extract_cpu "${dir}/vmstat.log")
+ dirty=$(extract_peak_dirty "${dir}/meminfo.log")
+ cached=$(extract_peak_cached "${dir}/meminfo.log")
+
+ printf "%-16s %10s %10s %10s %10s %10s %10s %10s %12s %12s\n" \
+ "$mode" "$mbps" "$iops" "$avg_lat" "$p50" "$p99" "$p999" \
+ "$cpu" "${dirty:-N/A}" "${cached:-N/A}"
+ done
+ echo ""
+done
+
+########################################################################
+# Deliverable 2: Multi-client results
+########################################################################
+echo "=================================================================="
+echo " Deliverable 2: Noisy-Neighbor Benchmarks"
+echo "=================================================================="
+echo ""
+
+# Scenario A: Multiple writers
+echo "--- Scenario A: Multiple Writers ---"
+for mode in buffered dontcache direct; do
+ dir="${RESULTS_DIR}/multi-write/${mode}"
+ if [ ! -d "$dir" ]; then
+ continue
+ fi
+
+ echo " Mode: $mode"
+ printf " %-10s %10s %10s %10s %10s %10s %10s\n" \
+ "Client" "MB/s" "IOPS" "Avg(us)" "p50(us)" "p99(us)" "p99.9(us)"
+
+ total_bw=0
+ count=0
+ for json_file in "${dir}"/client*.json; do
+ [ -f "$json_file" ] || continue
+ client=$(basename "$json_file" .json)
+ read -r mbps iops avg_lat p50 p99 p999 <<< \
+ "$(extract_metrics "$json_file" "write")"
+ printf " %-10s %10s %10s %10s %10s %10s %10s\n" \
+ "$client" "$mbps" "$iops" "$avg_lat" "$p50" "$p99" "$p999"
+ total_bw=$(echo "$total_bw + ${mbps:-0}" | bc 2>/dev/null || echo "$total_bw")
+ count=$(( count + 1 ))
+ done
+
+ cpu=$(extract_cpu "${dir}/vmstat.log")
+ dirty=$(extract_peak_dirty "${dir}/meminfo.log")
+ printf " Aggregate BW: %s MB/s | Sys CPU: %s%% | Peak Dirty: %s kB\n" \
+ "$total_bw" "$cpu" "${dirty:-N/A}"
+ echo ""
+done
+
+# Scenario C: Noisy neighbor
+echo "--- Scenario C: Noisy Writer + Latency-Sensitive Readers ---"
+for mode in buffered dontcache direct; do
+ dir="${RESULTS_DIR}/noisy-neighbor/${mode}"
+ if [ ! -d "$dir" ]; then
+ continue
+ fi
+
+ echo " Mode: $mode"
+ printf " %-14s %10s %10s %10s %10s %10s %10s\n" \
+ "Job" "MB/s" "IOPS" "Avg(us)" "p50(us)" "p99(us)" "p99.9(us)"
+
+ # Writer
+ if [ -f "${dir}/noisy_writer.json" ]; then
+ read -r mbps iops avg_lat p50 p99 p999 <<< \
+ "$(extract_metrics "${dir}/noisy_writer.json" "write")"
+ printf " %-14s %10s %10s %10s %10s %10s %10s\n" \
+ "Bulk writer" "$mbps" "$iops" "$avg_lat" "$p50" "$p99" "$p999"
+ fi
+
+ # Readers
+ for json_file in "${dir}"/reader*.json; do
+ [ -f "$json_file" ] || continue
+ reader=$(basename "$json_file" .json)
+ read -r mbps iops avg_lat p50 p99 p999 <<< \
+ "$(extract_metrics "$json_file" "read")"
+ printf " %-14s %10s %10s %10s %10s %10s %10s\n" \
+ "$reader" "$mbps" "$iops" "$avg_lat" "$p50" "$p99" "$p999"
+ done
+
+ cpu=$(extract_cpu "${dir}/vmstat.log")
+ dirty=$(extract_peak_dirty "${dir}/meminfo.log")
+ printf " Sys CPU: %s%% | Peak Dirty: %s kB\n" "$cpu" "${dirty:-N/A}"
+ echo ""
+done
+
+# Scenario D: Mixed-mode noisy neighbor
+echo "--- Scenario D: Mixed-Mode Noisy Writer + Readers ---"
+for dir in "${RESULTS_DIR}"/noisy-neighbor-mixed/*/; do
+ [ -d "$dir" ] || continue
+ label=$(basename "$dir")
+
+ echo " Mode: $label"
+ printf " %-14s %10s %10s %10s %10s %10s %10s\n" \
+ "Job" "MB/s" "IOPS" "Avg(us)" "p50(us)" "p99(us)" "p99.9(us)"
+
+ # Writer
+ if [ -f "${dir}/noisy_writer.json" ]; then
+ read -r mbps iops avg_lat p50 p99 p999 <<< \
+ "$(extract_metrics "${dir}/noisy_writer.json" "write")"
+ printf " %-14s %10s %10s %10s %10s %10s %10s\n" \
+ "Bulk writer" "$mbps" "$iops" "$avg_lat" "$p50" "$p99" "$p999"
+ fi
+
+ # Readers
+ for json_file in "${dir}"/reader*.json; do
+ [ -f "$json_file" ] || continue
+ reader=$(basename "$json_file" .json)
+ read -r mbps iops avg_lat p50 p99 p999 <<< \
+ "$(extract_metrics "$json_file" "read")"
+ printf " %-14s %10s %10s %10s %10s %10s %10s\n" \
+ "$reader" "$mbps" "$iops" "$avg_lat" "$p50" "$p99" "$p999"
+ done
+
+ cpu=$(extract_cpu "${dir}/vmstat.log")
+ dirty=$(extract_peak_dirty "${dir}/meminfo.log")
+ printf " Sys CPU: %s%% | Peak Dirty: %s kB\n" "$cpu" "${dirty:-N/A}"
+ echo ""
+done
+
+echo "=================================================================="
+echo " System Info"
+echo "=================================================================="
+if [ -f "${RESULTS_DIR}/sysinfo.txt" ]; then
+ head -6 "${RESULTS_DIR}/sysinfo.txt"
+fi
+echo ""
diff --git a/tools/testing/dontcache-bench/scripts/run-benchmarks.sh b/tools/testing/dontcache-bench/scripts/run-benchmarks.sh
new file mode 100755
index 0000000000000000000000000000000000000000..195d579e8eab8b7f827bb6438800c4933cdf236b
--- /dev/null
+++ b/tools/testing/dontcache-bench/scripts/run-benchmarks.sh
@@ -0,0 +1,518 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Local filesystem I/O mode benchmark suite.
+#
+# Runs the same test matrix as run-benchmarks.sh but on a local filesystem
+# using fio's io_uring engine with the RWF_DONTCACHE flag instead of NFSD's
+# debugfs mode knobs.
+#
+# Usage: ./run-local-benchmarks.sh [options]
+# -t Test directory (must be on a filesystem supporting FOP_DONTCACHE)
+# -s <size> File size (default: auto-sized to exceed RAM)
+# -f <path> Path to fio binary (default: fio in PATH)
+# -o Output directory for results (default: ./results/<timestamp>)
+# -d Dry run (print commands without executing)
+
+set -euo pipefail
+
+# Defaults
+TEST_DIR=""
+SIZE=""
+FIO_BIN="fio"
+RESULTS_DIR=""
+DRY_RUN=0
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+FIO_JOBS_DIR="${SCRIPT_DIR}/../fio-jobs"
+
+usage() {
+ echo "Usage: $0 -t <test-dir> [-s <size>] [-f <fio-path>] [-o <output-dir>] [-d]"
+ echo ""
+ echo " -t Test directory (required, must support RWF_DONTCACHE)"
+ echo " -s <size> File size (default: 2x RAM)"
+ echo " -f <path> Path to fio binary (default: fio)"
+ echo " -o Output directory (default: ./results/<timestamp>)"
+ echo " -d Dry run"
+ exit 1
+}
+
+while getopts "t:s:f:o:dh" opt; do
+ case $opt in
+ t) TEST_DIR="$OPTARG" ;;
+ s) SIZE="$OPTARG" ;;
+ f) FIO_BIN="$OPTARG" ;;
+ o) RESULTS_DIR="$OPTARG" ;;
+ d) DRY_RUN=1 ;;
+ h) usage ;;
+ *) usage ;;
+ esac
+done
+
+if [ -z "$TEST_DIR" ]; then
+ echo "ERROR: -t <test-dir> is required"
+ usage
+fi
+
+# Auto-size to 2x RAM if not specified
+if [ -z "$SIZE" ]; then
+ mem_kb=$(awk '/MemTotal/ {print $2}' /proc/meminfo)
+ SIZE="$(( mem_kb * 2 / 1024 ))M"
+fi
+
+if [ -z "$RESULTS_DIR" ]; then
+ RESULTS_DIR="./results/local-$(date +%Y%m%d-%H%M%S)"
+fi
+
+mkdir -p "$RESULTS_DIR"
+
+log() {
+ echo "[$(date '+%H:%M:%S')] $*"
+}
+
+run_cmd() {
+ if [ "$DRY_RUN" -eq 1 ]; then
+ echo " [DRY RUN] $*"
+ else
+ "$@"
+ fi
+}
+
+# I/O mode definitions:
+# buffered: direct=0, uncached=0
+# dontcache: direct=0, uncached=1
+# direct: direct=1, uncached=0
+#
+# Mode name from numeric value
+mode_name() {
+ case $1 in
+ 0) echo "buffered" ;;
+ 1) echo "dontcache" ;;
+ 2) echo "direct" ;;
+ esac
+}
+
+# Return fio command-line flags for a given mode.
+# "direct" is a standard fio option and works on the command line.
+# "uncached" is an io_uring engine option that must be in the job file,
+# so we inject it via make_job_file() below.
+mode_fio_args() {
+ case $1 in
+ 0) echo "--direct=0" ;; # buffered
+ 1) echo "--direct=0" ;; # dontcache
+ 2) echo "--direct=1" ;; # direct
+ esac
+}
+
+# Return the uncached= value for a given mode.
+mode_uncached() {
+ case $1 in
+ 0) echo "0" ;;
+ 1) echo "1" ;;
+ 2) echo "0" ;;
+ esac
+}
+
+# Create a temporary job file with uncached=N injected into [global].
+# For uncached=0 (buffered/direct), return the original file unchanged.
+make_job_file() {
+ local job_file=$1
+ local uncached=$2
+
+ if [ "$uncached" -eq 0 ]; then
+ echo "$job_file"
+ return
+ fi
+
+ local tmp
+ tmp=$(mktemp)
+ sed "/^\[global\]/a uncached=${uncached}" "$job_file" > "$tmp"
+ echo "$tmp"
+}
+
+drop_caches() {
+ run_cmd bash -c "sync && echo 3 > /proc/sys/vm/drop_caches"
+}
+
+# Background monitors
+VMSTAT_PID=""
+IOSTAT_PID=""
+MEMINFO_PID=""
+
+start_monitors() {
+ local outdir=$1
+ log "Starting monitors in $outdir"
+ run_cmd vmstat 1 > "${outdir}/vmstat.log" 2>&1 &
+ VMSTAT_PID=$!
+ run_cmd iostat -x 1 > "${outdir}/iostat.log" 2>&1 &
+ IOSTAT_PID=$!
+ (while true; do
+ echo "=== $(date '+%s') ==="
+ cat /proc/meminfo
+ sleep 1
+ done) > "${outdir}/meminfo.log" 2>&1 &
+ MEMINFO_PID=$!
+}
+
+stop_monitors() {
+ log "Stopping monitors"
+ kill "$VMSTAT_PID" "$IOSTAT_PID" "$MEMINFO_PID" 2>/dev/null || true
+ wait "$VMSTAT_PID" "$IOSTAT_PID" "$MEMINFO_PID" 2>/dev/null || true
+}
+
+cleanup_test_files() {
+ local filepath="${TEST_DIR}/$1"
+ log "Cleaning up $filepath"
+ run_cmd rm -f "$filepath"
+}
+
+# Run a single fio benchmark
+run_fio() {
+ local job_file=$1
+ local outdir=$2
+ local filename=$3
+ local fio_size=${4:-$SIZE}
+ local keep=${5:-}
+ local extra_args=${6:-}
+ local uncached=${7:-0}
+
+ # Inject uncached=N into the job file if needed
+ local actual_job
+ actual_job=$(make_job_file "$job_file" "$uncached")
+
+ local job_name
+ job_name=$(basename "$job_file" .fio)
+
+ log "Running fio job: $job_name -> $outdir (file=${TEST_DIR}/$filename size=$fio_size)"
+ mkdir -p "$outdir"
+
+ drop_caches
+ start_monitors "$outdir"
+
+ # shellcheck disable=SC2086
+ run_cmd "$FIO_BIN" "$actual_job" \
+ --output-format=json \
+ --output="${outdir}/${job_name}.json" \
+ --filename="${TEST_DIR}/$filename" \
+ --size="$fio_size" \
+ $extra_args
+
+ stop_monitors
+ log "Finished: $job_name"
+
+ # Clean up temp job file if one was created
+ [ "$actual_job" != "$job_file" ] && rm -f "$actual_job"
+
+ if [ "$keep" != "keep" ]; then
+ cleanup_test_files "$filename"
+ fi
+}
+
+########################################################################
+# Preflight
+########################################################################
+preflight() {
+ log "=== Preflight checks ==="
+
+ if ! command -v "$FIO_BIN" &>/dev/null; then
+ echo "ERROR: fio not found at $FIO_BIN"
+ exit 1
+ fi
+
+ if [ ! -d "$TEST_DIR" ]; then
+ echo "ERROR: Test directory $TEST_DIR does not exist"
+ exit 1
+ fi
+
+ # Quick check that RWF_DONTCACHE works on this filesystem
+ local testfile="${TEST_DIR}/.dontcache_test"
+ if ! "$FIO_BIN" --name=test --ioengine=io_uring --rw=write \
+ --bs=4k --size=4k --direct=0 --uncached=1 \
+ --filename="$testfile" 2>/dev/null; then
+ echo "WARNING: RWF_DONTCACHE may not be supported on $TEST_DIR"
+ echo " (filesystem must support FOP_DONTCACHE)"
+ fi
+ rm -f "$testfile"
+
+ log "Test directory: $TEST_DIR"
+ log "File size: $SIZE"
+ log "fio binary: $FIO_BIN"
+ log "Results: $RESULTS_DIR"
+
+ # Record system info
+ {
+ echo "Timestamp: $(date +%Y%m%d-%H%M%S)"
+ echo "Kernel: $(uname -r)"
+ echo "Hostname: $(hostname)"
+ echo "Filesystem: $(df -T "$TEST_DIR" | tail -1 | awk '{print $2}')"
+ echo "File size: $SIZE"
+ echo "Test dir: $TEST_DIR"
+ } > "${RESULTS_DIR}/sysinfo.txt"
+}
+
+########################################################################
+# Deliverable 1: Single-client benchmarks
+########################################################################
+run_deliverable1() {
+ log "=========================================="
+ log "Deliverable 1: Single-client benchmarks"
+ log "=========================================="
+
+ # Sequential write
+ for mode in 0 1 2; do
+ local mname
+ mname=$(mode_name $mode)
+ local fio_args
+ fio_args=$(mode_fio_args $mode)
+
+ drop_caches
+ run_fio "${FIO_JOBS_DIR}/seq-write.fio" \
+ "${RESULTS_DIR}/seq-write/${mname}" \
+ "seq-write_testfile" "$SIZE" "" "$fio_args" \
+ "$(mode_uncached $mode)"
+ done
+
+ # Random write
+ for mode in 0 1 2; do
+ local mname
+ mname=$(mode_name $mode)
+ local fio_args
+ fio_args=$(mode_fio_args $mode)
+
+ drop_caches
+ run_fio "${FIO_JOBS_DIR}/rand-write.fio" \
+ "${RESULTS_DIR}/rand-write/${mname}" \
+ "rand-write_testfile" "$SIZE" "" "$fio_args" \
+ "$(mode_uncached $mode)"
+ done
+
+ # Sequential read — pre-create file, then read with each mode
+ log "Pre-creating sequential read test file"
+ run_fio "${FIO_JOBS_DIR}/seq-write.fio" \
+ "${RESULTS_DIR}/seq-read/precreate" \
+ "seq-read_testfile" "$SIZE" "keep"
+
+ for rmode in 0 1 2; do
+ local mname
+ mname=$(mode_name $rmode)
+ local fio_args
+ fio_args=$(mode_fio_args $rmode)
+ local keep="keep"
+ [ "$rmode" -eq 2 ] && keep=""
+
+ drop_caches
+ run_fio "${FIO_JOBS_DIR}/seq-read.fio" \
+ "${RESULTS_DIR}/seq-read/${mname}" \
+ "seq-read_testfile" "$SIZE" "$keep" "$fio_args" \
+ "$(mode_uncached $rmode)"
+ done
+
+ # Random read — pre-create file, then read with each mode
+ log "Pre-creating random read test file"
+ run_fio "${FIO_JOBS_DIR}/seq-write.fio" \
+ "${RESULTS_DIR}/rand-read/precreate" \
+ "rand-read_testfile" "$SIZE" "keep"
+
+ for rmode in 0 1 2; do
+ local mname
+ mname=$(mode_name $rmode)
+ local fio_args
+ fio_args=$(mode_fio_args $rmode)
+ local keep="keep"
+ [ "$rmode" -eq 2 ] && keep=""
+
+ drop_caches
+ run_fio "${FIO_JOBS_DIR}/rand-read.fio" \
+ "${RESULTS_DIR}/rand-read/${mname}" \
+ "rand-read_testfile" "$SIZE" "$keep" "$fio_args" \
+ "$(mode_uncached $rmode)"
+ done
+}
+
+########################################################################
+# Deliverable 2: Multi-client tests
+########################################################################
+run_deliverable2() {
+ log "=========================================="
+ log "Deliverable 2: Noisy-neighbor benchmarks"
+ log "=========================================="
+
+ local num_clients=4
+ local client_size
+ local mem_kb
+ mem_kb=$(awk '/MemTotal/ {print $2}' /proc/meminfo)
+ client_size="$(( mem_kb / 1024 / num_clients ))M"
+
+ # Scenario A: Multiple writers
+ for mode in 0 1 2; do
+ local mname
+ mname=$(mode_name $mode)
+ local fio_args
+ fio_args=$(mode_fio_args $mode)
+ local uncached
+ uncached=$(mode_uncached $mode)
+ local actual_job
+ actual_job=$(make_job_file "${FIO_JOBS_DIR}/multi-write.fio" "$uncached")
+ local outdir="${RESULTS_DIR}/multi-write/${mname}"
+ mkdir -p "$outdir"
+
+ drop_caches
+ start_monitors "$outdir"
+
+ local pids=()
+ for i in $(seq 1 $num_clients); do
+ # shellcheck disable=SC2086
+ run_cmd "$FIO_BIN" "$actual_job" \
+ --output-format=json \
+ --output="${outdir}/client${i}.json" \
+ --filename="${TEST_DIR}/client${i}_testfile" \
+ --size="$client_size" \
+ $fio_args &
+ pids+=($!)
+ done
+
+ local rc=0
+ for pid in "${pids[@]}"; do
+ wait "$pid" || rc=$?
+ done
+
+ stop_monitors
+ [ $rc -ne 0 ] && log "WARNING: some fio jobs exited non-zero"
+
+ [ "$actual_job" != "${FIO_JOBS_DIR}/multi-write.fio" ] && rm -f "$actual_job"
+ for i in $(seq 1 $num_clients); do
+ cleanup_test_files "client${i}_testfile"
+ done
+ done
+
+ # Scenario C: Noisy writer + latency-sensitive readers
+ for mode in 0 1 2; do
+ local mname
+ mname=$(mode_name $mode)
+ local fio_args
+ fio_args=$(mode_fio_args $mode)
+ local uncached
+ uncached=$(mode_uncached $mode)
+ local writer_job
+ writer_job=$(make_job_file "${FIO_JOBS_DIR}/noisy-writer.fio" "$uncached")
+ local reader_job
+ reader_job=$(make_job_file "${FIO_JOBS_DIR}/lat-reader.fio" "$uncached")
+ local outdir="${RESULTS_DIR}/noisy-neighbor/${mname}"
+ mkdir -p "$outdir"
+
+ # Pre-create read files
+ for i in $(seq 1 $(( num_clients - 1 ))); do
+ log "Pre-creating read file for reader $i"
+ run_fio "${FIO_JOBS_DIR}/multi-write.fio" \
+ "${outdir}/precreate_reader${i}" \
+ "reader${i}_readfile" \
+ "512M" "keep"
+ done
+ drop_caches
+ start_monitors "$outdir"
+
+ # Noisy writer
+ # shellcheck disable=SC2086
+ run_cmd "$FIO_BIN" "$writer_job" \
+ --output-format=json \
+ --output="${outdir}/noisy_writer.json" \
+ --filename="${TEST_DIR}/bulk_testfile" \
+ --size="$SIZE" \
+ $fio_args &
+ local writer_pid=$!
+
+ # Latency-sensitive readers
+ local reader_pids=()
+ for i in $(seq 1 $(( num_clients - 1 ))); do
+ # shellcheck disable=SC2086
+ run_cmd "$FIO_BIN" "$reader_job" \
+ --output-format=json \
+ --output="${outdir}/reader${i}.json" \
+ --filename="${TEST_DIR}/reader${i}_readfile" \
+ --size="512M" \
+ $fio_args &
+ reader_pids+=($!)
+ done
+
+ local rc=0
+ wait "$writer_pid" || rc=$?
+ for pid in "${reader_pids[@]}"; do
+ wait "$pid" || rc=$?
+ done
+
+ stop_monitors
+ [ $rc -ne 0 ] && log "WARNING: some fio jobs exited non-zero"
+
+ [ "$writer_job" != "${FIO_JOBS_DIR}/noisy-writer.fio" ] && rm -f "$writer_job"
+ [ "$reader_job" != "${FIO_JOBS_DIR}/lat-reader.fio" ] && rm -f "$reader_job"
+ cleanup_test_files "bulk_testfile"
+ for i in $(seq 1 $(( num_clients - 1 ))); do
+ cleanup_test_files "reader${i}_readfile"
+ done
+ done
+
+ # Scenario D: Mixed-mode noisy neighbor
+ # dontcache writes + buffered reads
+ local outdir="${RESULTS_DIR}/noisy-neighbor-mixed/dontcache-w_buffered-r"
+ mkdir -p "$outdir"
+ local writer_job
+ writer_job=$(make_job_file "${FIO_JOBS_DIR}/noisy-writer.fio" 1)
+
+ for i in $(seq 1 $(( num_clients - 1 ))); do
+ log "Pre-creating read file for reader $i"
+ run_fio "${FIO_JOBS_DIR}/multi-write.fio" \
+ "${outdir}/precreate_reader${i}" \
+ "reader${i}_readfile" \
+ "512M" "keep"
+ done
+ drop_caches
+ start_monitors "$outdir"
+
+ # Writer with dontcache
+ run_cmd "$FIO_BIN" "$writer_job" \
+ --output-format=json \
+ --output="${outdir}/noisy_writer.json" \
+ --filename="${TEST_DIR}/bulk_testfile" \
+ --size="$SIZE" \
+ --direct=0 &
+ local writer_pid=$!
+
+ # Readers with buffered (no uncached flag)
+ local reader_pids=()
+ for i in $(seq 1 $(( num_clients - 1 ))); do
+ run_cmd "$FIO_BIN" "${FIO_JOBS_DIR}/lat-reader.fio" \
+ --output-format=json \
+ --output="${outdir}/reader${i}.json" \
+ --filename="${TEST_DIR}/reader${i}_readfile" \
+ --size="512M" \
+ --direct=0 &
+ reader_pids+=($!)
+ done
+
+ local rc=0
+ wait "$writer_pid" || rc=$?
+ for pid in "${reader_pids[@]}"; do
+ wait "$pid" || rc=$?
+ done
+
+ stop_monitors
+ [ $rc -ne 0 ] && log "WARNING: some fio jobs exited non-zero"
+
+ [ "$writer_job" != "${FIO_JOBS_DIR}/noisy-writer.fio" ] && rm -f "$writer_job"
+ cleanup_test_files "bulk_testfile"
+ for i in $(seq 1 $(( num_clients - 1 ))); do
+ cleanup_test_files "reader${i}_readfile"
+ done
+}
+
+########################################################################
+# Main
+########################################################################
+preflight
+run_deliverable1
+run_deliverable2
+
+log "=========================================="
+log "All benchmarks complete."
+log "Results in: $RESULTS_DIR"
+log "Parse with: scripts/parse-results.sh $RESULTS_DIR"
+log "=========================================="

--
2.53.0