diff a/test/hotspot/jtreg/premain/lib/bench-lib.sh b/test/hotspot/jtreg/premain/lib/bench-lib.sh
--- /dev/null
+++ b/test/hotspot/jtreg/premain/lib/bench-lib.sh
@@ -0,0 +1,316 @@
+# Copyright (c) 2023, 2024, Oracle and/or its affiliates. All rights reserved.
+# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+#
+# This code is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License version 2 only, as
+# published by the Free Software Foundation.
+#
+# This code is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+# version 2 for more details (a copy is included in the LICENSE file that
+# accompanied this code).
+#
+# You should have received a copy of the GNU General Public License version
+# 2 along with this work; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+# or visit www.oracle.com if you need additional information or have any
+# questions.
+
+#======================================================================
+# Overview
+#
+# This file provides the framework for running start-up benchmarks that have very
+# short elapsed time.
+#
+# The goal is to be able measure very minor improvements (under 1%) even when there
+# are system noises.
+#
+# - Measure the entire elapsed time with 'perf stat -r 16 bin/java .....'
+# - Interleave the execution of the test JVMs. This way, the effect of system noises 
+#   (CPU overheating, throttling, background tasks) is likely evenly distributed across
+#   the test JVMs.
+# - Save the results in a CSV file so you can load it in a spreadsheet and manually
+#   check for noisy samples.
+#
+# NOTE: you can see the effect of CPU throttling in the sample data below. See the
+# 2_xon column, which goes from 123ms when the CPU is cold to 128ms when the CPU is hot.
+
+#======================================================================
+# Config
+#
+# See ../javac_helloworld/run.sh for an example of using this file
+#
+# Before sourcing this file
+# The caller script should set up the following variables
+
+# required
+#     CMDLINE
+#     APP
+# optional
+#     HEAP_SIZE
+#     RUNS
+#     REPEAT
+
+# The number of the outer loop
+if test "$RUNS" = ""; then
+    RUNS=10
+fi
+
+# The number passed to "perf stat -r"
+if test "$REPEAT" = ""; then
+    REPEAT=16
+fi
+
+#======================================================================
+# Example
+#
+# FYI: Results I got on 2023/12/21, Intel(R) Core(TM) i7-10700 CPU @ 2.90GHz, 32MB RAM
+# With JDK mainline repo and leyden-premain branch that are pretty up to date.
+#
+# $ cd test/hotspot/jtreg/premain/javac_helloworld
+# $ bash run.sh /bld/mainline/images/jdk/bin/java /bld/leyden/images/jdk/bin/java
+# 
+# ===report.csv================================================
+# Run,1_xoff,1_xon,2_xon,2_td,2_aot
+# 1,313.86000,164.25000,123.031000,96.849000,92.38000
+# 2,324.59000,163.745000,122.550000,97.730000,92.45000
+# 3,313.61000,164.222000,122.91000,100.59000,91.18000
+# 4,316.58000,163.779000,124.673000,101.085000,95.10000
+# 5,313.002000,162.854000,126.240000,102.423000,91.81000
+# 6,314.97000,166.020000,126.148000,101.159000,91.43000
+# 7,313.30000,168.23000,128.19000,101.956000,88.13000
+# 8,314.67000,169.04000,126.168000,102.220000,91.90000
+# 9,313.26000,167.864000,125.856000,102.57000,90.75000
+# 10,318.14000,169.075000,128.055000,103.523000,93.61000
+# ==============================jvm1 /bld/mainline/images/jdk/bin/java
+# [1_xoff] Mainline JDK (CDS disabled)                   315.58 ms
+# [1_xon ] Mainline JDK (CDS enabled)                    165.89 ms
+# ==============================jvm2 /bld/leyden/images/jdk/bin/java
+# [2_xon ] Premain Prototype (CDS )                      125.37 ms
+# [2_td  ] Premain Prototype (CDS + Training Data)       100.99 ms
+# [2_aot ] Premain Prototype (CDS + Training Data + AOT)  91.86 ms
+# 
+#======================================================================
+
+
+# "$@" is the command-line specified by the user. Each element specifies a 
+# JVM (which optionally can contain VM parameters).
+#
+# We automatically detect whether the JVM is from the mainline, or from the leyden
+# repo.
+function main () {
+    do_dump "$@"
+    do_exec "$@"
+    do_summary "$@"
+}
+
+function do_dump () {
+    if test "$NODUMP" != ""; then
+        return
+    fi
+
+    local n=0
+    for i in "$@"; do
+        n=$(expr $n + 1)
+        JAVA="$i"
+        if test "$HEAP_SIZE" != ""; then
+            JAVA="$JAVA $HEAP_SIZE"
+        fi
+        dump_one_jvm $n
+    done
+}
+
+function do_exec () {
+    if test "$NOEXEC" != ""; then
+        return
+    fi
+
+    rm -rf logs
+    mkdir -p logs
+    rm -f report.csv
+
+    REPORT_HEADER='Run'
+
+    local n=0
+    for i in "$@"; do
+        n=$(expr $n + 1)
+        JAVA="$i"
+        if test "$HEAP_SIZE" != ""; then
+            JAVA="$JAVA $HEAP_SIZE"
+        fi
+        local APPID=$APP-jvm$n
+        if test -f $APPID-mainline.classlist; then
+            REPORT_HEADER=${REPORT_HEADER},${n}_xoff
+            REPORT_HEADER=${REPORT_HEADER},${n}_xon
+        else
+            REPORT_HEADER=${REPORT_HEADER},${n}_xon
+            REPORT_HEADER=${REPORT_HEADER},${n}_td
+            REPORT_HEADER=${REPORT_HEADER},${n}_aot
+        fi
+        #report jvm$n = $JAVA
+    done
+
+    report $REPORT_HEADER
+
+    # The #0 run is to warm up the CPU and is not counted
+    for r in $(seq 0 $RUNS); do
+        if test $r = 0; then
+            echo "RUN $r (warmup - discarded)"
+        else
+            echo "RUN $r of $RUNS"
+        fi
+        RUNLOG=$r
+        local n=0
+        for i in "$@"; do
+            n=$(expr $n + 1)
+            JAVA="$i"
+            if test "$HEAP_SIZE" != ""; then
+                JAVA="$JAVA $HEAP_SIZE"
+            fi
+            echo === jvm$n
+            exec_one_jvm $n $r
+        done
+
+        if test $r -gt 0; then
+            report $RUNLOG
+        else
+            echo $RUNLOG
+        fi
+    done
+}
+
+function dump_one_jvm () {
+    local binjava=$(echo $JAVA | sed -e 's/ .*//g')
+    local APPID=$APP-jvm$1
+
+    if $JAVA --version > /dev/null; then
+        if $JAVA -XX:+PrintFlagsFinal --version | grep CDSManualFinalImage > /dev/null; then
+            local is_premain=1
+            local type_msg="(premain 5 step)"
+        else
+            local is_premain=0
+            local type_msg="(mainline      )"
+        fi
+    else
+        echo "$JAVA doesn't seem to be a real JVM"
+        exit 1
+    fi
+
+    echo ========================================
+    echo dumping archive "$type_msg" for $JAVA
+    echo ========================================
+
+    if test $is_premain = 0; then
+        echo "(Mainline) Dump classlist"
+        (set -x; $JAVA -Xshare:off -XX:DumpLoadedClassList=$APPID-mainline.classlist $CMDLINE) || exit 1
+
+        echo "(Mainline) Dump CDS archive"
+        rm -f $APPID-mainline-static.dump.log
+        (set -x; $JAVA -Xshare:dump -XX:SharedArchiveFile=$APPID-mainline.jsa -XX:SharedClassListFile=$APPID-mainline.classlist \
+                       -Xlog:cds=debug,cds+class=debug:file=$APPID-mainline-static.dump.log::filesize=0 $CMDLINE) || exit 1
+
+    else
+        # FIXME -- add support for new workflow
+        LEYDEN_OPTS="-XX:+AOTClassLinking"
+
+        echo "(Premain STEP 1 of 5) Dump classlist"
+        (set -x; $JAVA -Xshare:off -XX:DumpLoadedClassList=$APPID.classlist $CMDLINE) || exit 1
+
+        echo "(Premain STEP 2 of 5) Create Static $APPID-static.jsa"
+        rm -f $APPID-static.dump.log
+        (set -x; $JAVA -Xshare:dump $LEYDEN_OPTS -XX:SharedArchiveFile=$APPID-static.jsa -XX:SharedClassListFile=$APPID.classlist \
+                       -Xlog:cds=debug,cds+class=debug,cds+resolve=debug:file=$APPID-static.dump.log::filesize=0 $CMDLINE) || exit 1
+
+
+        echo "(Premain STEP 3 of 5) Run with $APPID-static.jsa and dump profile in $APPID-dynamic.jsa (With Training Data Replay)"
+        rm -f $APPID-dynamic.dump.log
+        (set -x; $JAVA -XX:SharedArchiveFile=$APPID-static.jsa -XX:ArchiveClassesAtExit=$APPID-dynamic.jsa -XX:+RecordTraining \
+                       -Xlog:cds=debug,cds+class=debug:file=$APPID-dynamic.dump.log::filesize=0 $CMDLINE) || exit 1
+
+        echo "(Premain  4 of 5) Run with $APPID-dynamic.jsa and generate AOT code"
+        rm -f $APPID-store-sc.log
+        (set -x; $JAVA -XX:SharedArchiveFile=$APPID-dynamic.jsa -XX:+ReplayTraining -XX:+StoreCachedCode \
+                       -Xlog:scc*=warning:file=$APPID-store-sc.log::filesize=0 \
+                       -XX:CachedCodeFile=$APPID-dynamic.jsa-sc -XX:CachedCodeMaxSize=100M $CMDLINE) || exit 1
+
+    fi
+}
+
+function exec_one_jvm () {
+    local APPID=$APP-jvm$1
+
+    if test -f $APPID-mainline.classlist; then
+        (set -x;
+         perf stat -r $REPEAT $JAVA -Xshare:off $CMDLINE 2> logs/${1}_xoff.$2
+        )
+        RUNLOG=$RUNLOG,$(get_elapsed logs/${1}_xoff.$2)
+
+        (set -x;
+         perf stat -r $REPEAT $JAVA -XX:SharedArchiveFile=$APPID-mainline.jsa $CMDLINE 2> logs/${1}_xon.$2
+        )
+        RUNLOG=$RUNLOG,$(get_elapsed logs/${1}_xon.$2)
+    fi
+
+    if test -f $APPID.classlist; then
+        (set -x;
+         perf stat -r $REPEAT $JAVA -XX:SharedArchiveFile=$APPID-static.jsa $CMDLINE 2> logs/${1}_xon.$2
+        )
+        RUNLOG=$RUNLOG,$(get_elapsed logs/${1}_xon.$2)
+        (set -x;
+         perf stat -r $REPEAT $JAVA -XX:SharedArchiveFile=$APPID-dynamic.jsa -XX:+ReplayTraining \
+              $CMDLINE 2> logs/${1}_td.$2
+        )
+        RUNLOG=$RUNLOG,$(get_elapsed logs/${1}_td.$2)
+        (set -x;
+         perf stat -r $REPEAT $JAVA -XX:SharedArchiveFile=$APPID-dynamic.jsa -XX:+ReplayTraining -XX:+LoadCachedCode \
+              -XX:CachedCodeFile=$APPID-dynamic.jsa-sc -Xlog:scc=error \
+              $CMDLINE 2> logs/${1}_aot.$2
+        )
+        RUNLOG=$RUNLOG,$(get_elapsed logs/${1}_aot.$2)
+    fi
+}
+
+function get_elapsed () {
+    elapsed=$(bc <<< "scale=3; $(cat $1 | grep elapsed | sed -e 's/[+].*//') * 1000")
+    echo $elapsed >> $1.elapsed
+    echo $elapsed
+}
+
+
+function report () {
+    echo "$@"
+    echo "$@" >> report.csv
+}
+
+function geomean () {
+    printf "%6.2f ms" $(awk 'BEGIN{E = exp(1);} $1>0{tot+=log($1); c++} END{m=tot/c; printf "%.2f\n", E^m}' $*)
+}
+
+
+
+function do_summary () {
+    echo ===report.csv================================================
+    cat report.csv
+
+    mkdir -p logs/warmup
+    mv logs/*.0.elapsed logs/*.0 logs/warmup
+    local n=0
+    for i in "$@"; do
+        n=$(expr $n + 1)
+        local APPID=$APP-jvm$n
+        report ==============================jvm$n $i
+        if test -f $APPID-mainline.classlist; then
+            report "[$(printf %-6s ${n}_xoff)] Mainline JDK (CDS disabled)                   $(geomean logs/${n}_xoff.*.elapsed)"
+            report "[$(printf %-6s ${n}_xon )] Mainline JDK (CDS enabled)                    $(geomean logs/${n}_xon.*.elapsed)"
+        else
+            report "[$(printf %-6s ${n}_xon )] Premain Prototype (CDS )                      $(geomean logs/${n}_xon.*.elapsed)"
+            report "[$(printf %-6s ${n}_td  )] Premain Prototype (CDS + Training Data)       $(geomean logs/${n}_td.*.elapsed)"
+            report "[$(printf %-6s ${n}_aot )] Premain Prototype (CDS + Training Data + AOT) $(geomean logs/${n}_aot.*.elapsed)"
+        fi
+    done
+}
+
+main "$@"
