diff --git a/bench-boot b/bench-boot
index 41bb61c..161b630 100755
--- a/bench-boot
+++ b/bench-boot
@@ -2,9 +2,9 @@
 set -eu
 . common
 results_file="${out_dir}/bench-boot.txt"
+caches='--caches --l2cache --l1d_size=1024kB --l1i_size=1024kB --l2_size=1024kB --l3_size=1024kB'
 bench() (
-  printf 'cmd ' >> "$results_file"
-  env time --append -f 'time %e' --output="$results_file" ./eeval "./run -a $1" "$results_file"
+  common_bench_cmd "./run -a ${1}" "$results_file"
 )
 gem5_insts() (
   printf "instructions $(./gem5-stat -a "$1" sim_insts)\n" >> "$results_file"
@@ -19,11 +19,14 @@ rm -f "${results_file}"
 
 arch=x86_64
 bench "$arch -E '/poweroff.out'"
-bench "$arch -E '/poweroff.out' -- -enable-kvm"
+bench "$arch -E '/poweroff.out' -K"
 bench "$arch -E '/poweroff.out' -T exec_tb"
 qemu_insts "$arch"
 bench "$arch -E 'm5 exit' -g"
 gem5_insts "$arch"
+# Was taking more than one hour.
+#bench "$arch -E 'm5 exit' -g -- --cpu-type=DerivO3CPU ${caches}"
+#gem5_insts "$arch"
 
 arch=arm
 # Manual Ctrl+C required.
@@ -32,6 +35,7 @@ arch=arm
 #qemu_insts "$arch"
 bench "$arch -E 'm5 exit' -g"
 gem5_insts "$arch"
+# Was taking more than one hour.
 #bench "$arch -E 'm5 exit' -g -- --caches --cpu-type=HPI"
 #gem5_insts "$arch"
 
@@ -41,5 +45,5 @@ bench "$arch -E '/poweroff.out' -T exec_tb"
 qemu_insts "$arch"
 bench "$arch -E 'm5 exit' -g"
 gem5_insts "$arch"
-bench "$arch -E 'm5 exit' -g -- --caches --cpu-type=HPI"
+bench "$arch -E 'm5 exit' -g -- --cpu-type=HPI ${caches}"
 gem5_insts "$arch"
diff --git a/build b/build
index 77bfeff..748efc2 100755
--- a/build
+++ b/build
@@ -187,5 +187,4 @@ V='${v}' \\
 ${extra_make_args} \
 all \\
 "
-echo "$cmd" | tee "${out_arch_dir}/build.sh"
-eval "$cmd"
+./eeval "$cmd" "${out_arch_dir}/build.sh"
diff --git a/common b/common
index 3f10f92..ebfbce8 100644
--- a/common
+++ b/common
@@ -1,4 +1,21 @@
 #!/usr/bin/env bash
+common_bench_cmd() (
+  # Benchmark a command.
+  #
+  # $1: command to benchmark
+  # $2: where to write results to
+  #
+  # Result format:
+  #
+  # cmd <command run>
+  # time <time in seconds to finish>
+  # status <exit status>
+  cmd="$1"
+  results_file="$2"
+  printf 'cmd ' >> "$results_file"
+  env time --append -f 'time %e' --output="$results_file" ./eeval -a "$cmd" "$results_file"
+  printf "status $?\n" >> "$results_file"
+)
 set_common_vars() {
   arch="$1"
   gem5="${2:-false}"
diff --git a/eeval b/eeval
index 7cef72b..4ab747c 100755
--- a/eeval
+++ b/eeval
@@ -1,4 +1,20 @@
 #!/usr/bin/env bash
+# echo and eval
+a=
+while getopts a OPT; do
+  case "$OPT" in
+    a)
+      # Append to file instead of overwriting.
+      a=-a
+      ;;
+    ?)
+      exit 2
+      ;;
+  esac
+done
+shift "$(($OPTIND - 1))"
 cmd="$1"
-echo "$cmd" | tee -a "${2:-/dev/null}"
+outfile="${2:-/dev/null}"
+echo "$cmd" | tee $a "$outfile"
 eval "$cmd"
+exit "$?"
diff --git a/gem5-bench-cache b/gem5-bench-cache
index eb47a4f..dbe2920 100755
--- a/gem5-bench-cache
+++ b/gem5-bench-cache
@@ -19,12 +19,10 @@ set_common_vars "$arch" true
 cmd="./run -a $arch -g"
 cache_small='--caches --l2cache --l1d_size=1024   --l1i_size=1024   --l2_size=1024   --l3_size=1024  '
 cache_large='--caches --l2cache --l1d_size=1024kB --l1i_size=1024kB --l2_size=1024kB --l3_size=1024kB'
-result_file="${gem5_out_dir}/bench-cache.txt"
+results_file="${gem5_out_dir}/bench-cache.txt"
 
 bench() (
-  cmd="$1"
-  printf 'cmd ' >> "$result_file"
-  ./eeval "$cmd" "$result_file"
+  common_bench_cmd "$1" "$results_file"
   {
     printf 'cycles '
     ./gem5-stat -a "$arch"
@@ -33,7 +31,7 @@ bench() (
     #if [ -n "$cycles_switch" ]; then
     #  printf "cycles_switch ${cycles_switch}\n"
     #fi
-  } >> "$result_file"
+  } >> "$results_file"
 )
 
 bench-all() (
@@ -67,7 +65,7 @@ bench-all() (
 if "$generate_checkpoints"; then
   # Create the checkpoints after the kernel boot.
   rm -rf "${m5out_dir}"/cpt.*;
-  printf 'm5 exit' >"${readfile_file}"
+  printf 'm5 exit' > "${readfile_file}"
   cpt_cmd="-E 'm5 checkpoint;m5 readfile > a.sh;sh a.sh'"
   # 1
   ./eeval "$cmd $cpt_cmd"
@@ -83,14 +81,15 @@ if "$generate_checkpoints"; then
 fi
 
 # Restore and run benchmarks.
-rm -f "$result_file"
+rm -f "$results_file"
 printf '#!/bin/sh
 m5 resetstats
 dhrystone XXX
 m5 exit
 ' >"${readfile_file}"
 for n in 1000 10000 100000; do
-  printf "n ${n}\n" >> "$result_file"
+  printf "n ${n}\n" >> "$results_file"
   sed -Ei "s/^dhrystone .*/dhrystone ${n}/" "${readfile_file}"
   bench-all
+  printf "\n" >> "$results_file"
 done
diff --git a/run b/run
index 7f0d5e2..dd6bc15 100755
--- a/run
+++ b/run
@@ -296,5 +296,4 @@ if "$tmux"; then
     eval "./tmu 'sleep 2;./gem5-shell'"
   fi
 fi
-echo "$cmd" | tee "${out_arch_dir}/run.sh"
-eval "$cmd"
+./eeval "$cmd" "${out_arch_dir}/run.sh"
diff --git a/rungdb b/rungdb
index 15f40f2..150da04 100755
--- a/rungdb
+++ b/rungdb
@@ -89,6 +89,4 @@ ${brk} \
 ${lx_symbols} \
 "
 fi
-cmd="$cmd $after"
-echo "$cmd" | tee "${out_arch_dir}/rungdb.sh"
-eval "$cmd"
+./eeval "$cmd $after" "${out_arch_dir}/rungdb.sh"