diff --git a/utils/babeltrace_thapi.in b/utils/babeltrace_thapi.in
index eee4822e..924de2e2 100755
--- a/utils/babeltrace_thapi.in
+++ b/utils/babeltrace_thapi.in
@@ -1,31 +1,27 @@
 #!/usr/bin/env ruby
 DATADIR = File.join('@prefix@', 'share')
-$:.unshift(DATADIR) if File.directory?(DATADIR)
+$LOAD_PATH.unshift(DATADIR) if File.directory?(DATADIR)
 require 'optparse'
 require 'babeltrace2'
 require 'find'
 
-module MyRefinement
-
+module BTComponentClassRefinement
   refine(BT2::BTComponentClass) do
-      attr_accessor :plugin
+    attr_accessor :plugin
   end
 
   refine(BT2::BTPlugin.singleton_class) do
-
     def find_all_from_dir(path, recurse: false, fail_on_load_error: true)
-        # I guess print a warning if recurse?
-        ps = super
-        ps.each { |p|
-          p.path = path
-        }
-        ps
+      # I guess print a warning if recurse?
+      ps = super
+      ps.each do |p|
+        p.path = path
+      end
+      ps
     end
-
   end
 
   refine(BT2::BTPlugin) do
-
     attr_accessor :path
 
     def get_source_component_class_by_name(name)
@@ -63,18 +59,15 @@ module MyRefinement
       cs.each { |c| c.plugin = self }
       cs
     end
-
   end
   refine(BT2::BTGraph.singleton_class) do
-
     def new(handle = nil, retain: true, auto_release: true,
-                   mip_version: 0)
+            mip_version: 0)
       obj = super
       obj.plugins_path = []
       obj.cli_v = []
       obj
     end
-
   end
 
   refine(BT2::BTGraph) do
@@ -86,7 +79,7 @@ module MyRefinement
 
       @plugins_path << component_class.plugin.path
       @cli_v << "--component #{name}:#{component_class.type.to_s.split('_').last.downcase}.#{component_class.plugin.name}.#{component_class.name}"
-      str_params = params.filter_map { |k,v| "#{k}=#{v}" unless v.class == String && v.empty? }.join(",")
+      str_params = params.filter_map { |k, v| "#{k}=#{v}" unless v.instance_of?(String) && v.empty? }.join(',')
       @cli_v << "--params #{str_params.dump}" unless str_params.empty?
       super
     end
@@ -97,18 +90,17 @@ module MyRefinement
     end
 
     def cli
-      l = ["babeltrace2"]
+      l = ['babeltrace2']
       ps_u = @plugins_path.uniq.compact.sort
-      l << "--plugin-path=#{ps_u.join(",")}" unless ps_u.empty?
-      l << "run"
+      l << "--plugin-path=#{ps_u.join(',')}" unless ps_u.empty?
+      l << 'run'
       l += @cli_v
       l.join(" \\\n")
     end
-
   end
 end
 
-using MyRefinement
+using BTComponentClassRefinement
 
 # Don't complain about broken pipe
 Signal.trap('SIGPIPE', 'SYSTEM_DEFAULT')
@@ -133,12 +125,120 @@ $options_tally = {
   'backend_level' => [String, ''],
 }
 
+NameComp = Struct.new(:name, :comp)
+
+def get_components(names)
+  # BT "native" component classes
+  components_classes = {
+    'source.ctf.fs' => BT2::BTPlugin.find('ctf').get_source_component_class_by_name('fs'),
+    'source.ctf.lttng_live' => BT2::BTPlugin.find('ctf').get_source_component_class_by_name('lttng-live'),
+    'filter.utils.muxer' => BT2::BTPlugin.find('utils').get_filter_component_class_by_name('muxer'),
+    'sink.text.pretty' => BT2::BTPlugin.find('text').get_sink_component_class_by_name('pretty'),
+    'sink.ctf.fs' => BT2::BTPlugin.find('ctf').get_sink_component_class_by_name('fs'),
+    'sink.utils.dummy' => BT2::BTPlugin.find('utils').get_sink_component_class_by_name('dummy'),
+  }
+
+  # THAPI components
+  thapi_plugins = BT2::BTPlugin.find_all_from_dir(File.join('@prefix@', 'lib'))
+  thapi_plugins.map do |pg|
+    pg.source_component_classes.each { |c| components_classes["source.#{pg.name}.#{c.name}"] = c }
+    pg.filter_component_classes.each { |c| components_classes["filter.#{pg.name}.#{c.name}"] = c }
+    pg.sink_component_classes.each { |c| components_classes["sink.#{pg.name}.#{c.name}"] = c }
+  end
+
+  names.flat_map do |name|
+    case name
+    when 'filter.intervals.interval'
+      $options[:backends].map { |b| NameComp.new(b, components_classes["filter.#{b}interval.interval"]) }
+    when 'sink.text.rubypretty'
+      # Yaml and event_lambdas are required by babeltrace*_lib
+      $event_lambdas = {}
+      require 'yaml'
+      require 'babeltrace_omp_lib' if $options[:backends].include?('omp')
+      require 'babeltrace_opencl_lib' if $options[:backends].include?('cl')
+      require 'babeltrace_ze_lib' if $options[:backends].include?('ze')
+      require 'babeltrace_cuda_lib' if $options[:backends].include?('cuda')
+      require 'babeltrace_hip_lib' if $options[:backends].include?('hip')
+      f = lambda { |iterator, _|
+        iterator.next_messages.each do |m|
+          next unless m.type == :BT_MESSAGE_TYPE_EVENT
+
+          e = m.event
+          l = $event_lambdas[e.name]
+          next unless l || !$options[:restrict]
+
+          str = Time.at(0, m.get_default_clock_snapshot.ns_from_origin, :nsec).strftime('%H:%M:%S.%9L').to_s
+          if $options[:context]
+            str << " - #{e.stream.trace.get_environment_entry_value_by_name('hostname')}"
+            str << ' - ' << e.get_common_context_field.value.collect do |k, v|
+              "#{k}: #{v}"
+            end.join(', ')
+          end
+          str << " - #{e.name}: "
+          str << (l ? l.call(e.payload_field.value) : e.payload_field.to_s)
+          puts str
+        end
+      }
+      NameComp.new('sink.text.rubypretty', f)
+    else
+      NameComp.new(name, components_classes[name])
+    end
+  end
+end
+
+def get_and_add_components(graph, names)
+  get_components(names).map do |nc|
+    name = nc.name
+    comp = nc.comp
+    case name
+    when 'sink.text.rubypretty'
+      graph.add_simple_sink('rubypretty', comp)
+    when 'source.ctf.lttng_live'
+      graph.add(comp, 'source_live',
+                params: { 'inputs' => $options[:inputs],
+                          'session-not-found-action' => 'end' })
+    when 'source.ctf.fs'
+      Find.find(*ARGV)
+          .reject { |path| FileTest.directory?(path) }
+          .filter_map { |path| File.dirname(path) if File.basename(path) == 'metadata' }
+          .select do |path|
+            qe = BT2::BTQueryExecutor.new(component_class: comp, object_name: 'babeltrace.support-info',
+                                          params: { 'input' => path, 'type' => 'directory' })
+            qe.query.value['weight'] > 0.5
+          end
+          .each_with_index.map do |trace_location, i|
+            graph.add(comp, "source_#{i}",
+                      params: { 'inputs' => [trace_location] })
+          end
+    when 'sink.ctf.fs'
+      graph.add(comp, 'ctf_sink',
+                params: { 'path' => $options[:output],
+                          'assume-single-trace' => false,
+                          'quiet' => $options[:debug] ? false : true })
+    when 'sink.btx_tally.tally'
+      graph.add(comp, 'tally',
+                params: $options_tally.transform_values { |_, v| v })
+    else
+      graph.add(comp, name)
+    end
+  end
+end
+
+def connects(graph, comps)
+  comps.each_cons(2) do |out, in_|
+    [out].flatten.flat_map(&:output_ports).each_with_index do |op, i|
+      ip = in_.input_port(i)
+      graph.connect_ports(op, ip)
+    end
+  end
+end
+
 def common_options(opts)
   opts.on('-b', '--backend BACKEND', Array) do |v|
     $options[:backends] = v
   end
 
-  opts.on('--debug') do |v|
+  opts.on('--debug') do |_v|
     $options[:debug] = true
   end
 
@@ -171,6 +271,19 @@ subcommands = {
         $options[:live] = true
       end
     end,
+  'live2aggreg' =>
+    OptionParser.new do |opts|
+      opts.banner = 'Usage: live2aggreg [OPTIONS]'
+      common_options(opts)
+
+      opts.on('--inputs=INPUTS') do |inputs|
+        $options[:inputs] = [inputs]
+      end
+
+      opts.on('--output=OUTPUT') do |output|
+        $options[:output] = output
+      end
+    end,
   'tally' =>
     OptionParser.new do |opts|
       opts.banner = 'Usage: tally [OPTIONS] trace_directory...'
@@ -180,6 +293,17 @@ subcommands = {
         $options[:live] = true
       end
 
+      $options_tally.each do |k, (t, _)|
+        opts.on("--#{k}=VALUE", t) do |v|
+          $options_tally[k] = [t, v]
+        end
+      end
+    end,
+  'aggreg2tally' =>
+    OptionParser.new do |opts|
+      opts.banner = 'Usage: aggreg2tally [OPTIONS] trace_directory...'
+      common_options(opts)
+
       $options_tally.each do |k, (t, _)|
         opts.on("--#{k}=VALUE", t) do |v|
           $options_tally[k] = [t, v]
@@ -205,123 +329,25 @@ subcommands[command].order!
 # Fix segfault
 ARGV.uniq!
 
-# BT "native" component classes
-components_classes = {
-  'source.ctf.fs' => BT2::BTPlugin.find('ctf').get_source_component_class_by_name('fs'),
-  'source.ctf.lttng_live' => BT2::BTPlugin.find('ctf').get_source_component_class_by_name('lttng-live'),
-  'filter.utils.muxer' => BT2::BTPlugin.find('utils').get_filter_component_class_by_name('muxer'),
-  'sink.text.pretty' => BT2::BTPlugin.find('text').get_sink_component_class_by_name('pretty'),
-}
-
-# THAPI components
-thapi_plugins = BT2::BTPlugin.find_all_from_dir(File.join('@prefix@', 'lib'))
-thapi_plugins.map do |pg|
-  pg.source_component_classes.each { |c| components_classes["source.#{pg.name}.#{c.name}"] = c }
-  pg.filter_component_classes.each { |c| components_classes["filter.#{pg.name}.#{c.name}"] = c }
-  pg.sink_component_classes.each { |c| components_classes["sink.#{pg.name}.#{c.name}"] = c }
-end
+thapi_graph = { 'tally' => ['source.ctf.fs', 'filter.utils.muxer', 'filter.intervals.interval',
+                            'filter.btx_aggreg.aggreg', 'sink.btx_tally.tally'],
+                'timeline' => ['source.ctf.fs', 'filter.utils.muxer', 'filter.intervals.interval',
+                               'sink.btx_timeline.timeline'],
+                'trace' => ['source.ctf.fs', 'filter.utils.muxer', 'sink.text.rubypretty'],
+                'live2aggreg' => ['source.ctf.lttng_live', 'filter.utils.muxer', 'filter.intervals.interval',
+                                  'filter.btx_aggreg.aggreg', 'sink.ctf.fs'],
+                'aggreg2tally' => ['source.ctf.fs', 'filter.btx_aggreg.aggreg', 'sink.btx_tally.tally'] }
 
 graph = BT2::BTGraph.new
-
-# Source components
-if !$options[:live]
-  ctf_fs = components_classes.fetch('source.ctf.fs')
-
-  trace_locations =
-    Find.find(*ARGV).reject do |path|
-      FileTest.directory?(path)
-    end.select do |path|
-      File.basename(path) == 'metadata'
-    end.collect do |path|
-      File.dirname(path)
-    end.select do |path|
-      qe = BT2::BTQueryExecutor.new(component_class: ctf_fs, object_name: 'babeltrace.support-info',
-                                    params: { 'input' => path, 'type' => 'directory' })
-      qe.query.value['weight'] > 0.5
-    end
-
-  comp_sources = trace_locations.each_with_index.map do |trace_location, i|
-    graph.add_component(ctf_fs, "source_#{i}", params: { 'inputs' => [trace_location] })
-  end
-else
-  trace_locations = ARGV
-  ctf_lttng_live = components_classes.fetch('source.ctf.lttng_live')
-  comp_sources = trace_locations.each_with_index.map do |trace_location, i|
-    graph.add_component(ctf_lttng_live, "source_#{i}",
-                        params: { 'inputs' => [trace_location], 'session-not-found-action' => 'end' })
-  end
-end
-
-# Muxer components
-comp_muxer = graph.add_component(components_classes.fetch('filter.utils.muxer'), 'muxer')
-
-# Sources to muxer connection
-comp_sources.flat_map(&:output_ports).each_with_index do |op, i|
-  ip = comp_muxer.input_port(i)
-  graph.connect_ports(op, ip)
-end
-
-# Rest of graph components
-comps = []
-case command
-when 'trace'
-  # Yaml and event_lambdas are required by babeltrace*_lib
-  $event_lambdas = {}
-  require 'yaml'
-  require 'babeltrace_omp_lib' if $options[:backends].include?('omp')
-  require 'babeltrace_opencl_lib' if $options[:backends].include?('cl')
-  require 'babeltrace_ze_lib' if $options[:backends].include?('ze')
-  require 'babeltrace_cuda_lib' if $options[:backends].include?('cuda')
-  require 'babeltrace_hip_lib' if $options[:backends].include?('hip')
-
-  consume = lambda { |iterator, _|
-    iterator.next_messages.each do |m|
-      next unless m.type == :BT_MESSAGE_TYPE_EVENT
-
-      e = m.event
-      l = $event_lambdas[e.name]
-      next unless l || !$options[:restrict]
-
-      str = "#{Time.at(0, m.get_default_clock_snapshot.ns_from_origin, :nsec).strftime('%H:%M:%S.%9L')}"
-      if $options[:context]
-        str << " - #{e.stream.trace.get_environment_entry_value_by_name('hostname')}"
-        str << ' - ' << e.get_common_context_field.value.collect do |k, v|
-          "#{k}: #{v}"
-        end.join(', ')
-      end
-      str << " - #{e.name}: "
-      str << (l ? l.call(e.payload_field.value) : e.payload_field.to_s)
-      puts str
-    end
-  }
-  comps << graph.add_simple_sink('babeltrace_thapi', consume)
-when 'tally'
-  $options[:backends].each do |name|
-    comps << graph.add_component(components_classes.fetch("filter.#{name}interval.interval"), "#{name}interval")
-  end
-  comps << graph.add_component(components_classes.fetch('filter.btx_aggreg.aggreg'), 'aggreg')
-  comps << graph.add_component(components_classes.fetch('sink.btx_tally.tally'), 'tally',
-                               params: $options_tally.transform_values { |_, v| v })
-when 'timeline'
-  $options[:backends].each do |name|
-    comps << graph.add_component(components_classes.fetch("filter.#{name}interval.interval"), "#{name}interval")
-  end
-  comps << graph.add_component(components_classes.fetch('sink.btx_timeline.timeline'), 'timeline')
-end
-
-# Muxer to serial part
-[comp_muxer, comps].flatten.each_cons(2) do |_out, _in|
-  op = _out.output_port(0)
-  ip = _in.input_port(0)
-  graph.connect_ports(op, ip)
-end
+comp = get_and_add_components(graph, thapi_graph[command])
+connects(graph, comp)
 
 if $options[:debug]
   cli = graph.cli
-  #puts cli
-  puts "babeltrace_thapi: babeltrace2 cli command will be saved in ./babeltrace_thapi_cli.sh"
+  # puts cli
+  puts 'babeltrace_thapi: babeltrace2 cli command will be saved in ./babeltrace_thapi_cli.sh'
   $stdout.flush
-  File::open('babeltrace_thapi_cli.sh','w') { |f| f.write(cli) }
+  File.open('babeltrace_thapi_cli.sh', 'w') { |f| f.write(cli) }
 end
 
 graph.run
diff --git a/xprof/xprof.sh.erb.in b/xprof/xprof.sh.erb.in
index 7dfd5710..46180db1 100644
--- a/xprof/xprof.sh.erb.in
+++ b/xprof/xprof.sh.erb.in
@@ -85,7 +85,7 @@ echoq() {
 
 count_file() {
     # https://unix.stackexchange.com/a/90152
-    a=$(2>/dev/null \ls  -afq $1 | wc -l)
+    a=$(2>/dev/null \ls -afq $1 | wc -l)
     echo $((a - 2))
 }
 
@@ -306,7 +306,7 @@ setup_lttng() {
 
     local suffix=""
     if [ ${1:-""} = "--live" ]; then
-        suffix="_live"
+        suffix="-aggreg"
     fi
 
 <% if ["omp","ze","cuda","cl","hip"].all? { |l| languages.include?(l) } %>
@@ -358,7 +358,7 @@ preload_lib_tracers() {
     if [[ "$traced_ranks" == "-1" ]] || [[ "$IFS$traced_ranks$IFS" =~ "$IFS$(mpi_rank_id)$IFS" ]]; then
 <% if languages.include?("omp") %>
     thapi_export LTTNG_UST_OMP_INTEL 1
-    thapi_export OMP_TOOL_LIBRARIES  $libdir/libTracerOMPT.so
+    thapi_export OMP_TOOL_LIBRARIES $libdir/libTracerOMPT.so
 <% end %>
 <% if languages.include?("cl") %>
 <%= print_loader_logic("opencl","libOpenCL","libTracerOpenCL")%>
@@ -387,7 +387,7 @@ local_master_epilogue() {
     lttngq stop THAPI_$(hostname)
     lttngq destroy THAPI_$(hostname)
     if [ ${1:-""} = "--live" ]; then
-        wait $BT_PID # Set setub_babeltrace_live
+        wait $BT_PID # assigned by setup_babeltrace_live
     fi
     global_barrier_epilogue
     rm -rf -- "$SHARED_LOCAL_FILESYSTEM"
@@ -432,18 +432,22 @@ trace_and_summary() {
     "$@"
 }
 
-bt2_all() {
-    # Note that the $@ are not quoted!
-    if [ -n "${trace-}" ]; then
-        $bindir/babeltrace_thapi $([ $debug == true ] && echo "--debug") --backend <%= languages %> -r -c $@
-    fi
+call_babeltrace_thapi() {
 
-    if [ -n "${timeline-}" ]; then
-        $bindir/babeltrace_thapi timeline $([ $debug == true ] && echo "--debug") --backend <%= languages %> $@
-    fi
+    local btt_debug_flag=$([ $debug == true ] && echo "--debug" || echo "")
+    local btt_common_flag="--backend <%= languages %> $btt_debug_flag"
 
-    if [ -z "${timeline-}" ] && [ -z "${trace-}" ]; then
-        $bindir/babeltrace_thapi tally $([ $debug == true ] && echo "--debug") --backend <%= languages %> $bt_tally_argv -- $@
+    if [ $mode == "tally" ] && [ $processing_mode == "post-process" ]; then
+      $bindir/babeltrace_thapi tally $btt_common_flag $bt_tally_argv -- $@
+    elif [ $mode == "tally" ] && [ $processing_mode == "on-the-fly" ]; then
+      $bindir/babeltrace_thapi aggreg2tally $btt_common_flag $bt_tally_argv -- $@
+    elif [ $mode == "trace" ] && [ $processing_mode == "post-process" ]; then
+      $bindir/babeltrace_thapi trace $btt_common_flag --restrict --context -- $@
+    elif [ $mode == "timeline" ] && [ $processing_mode == "post-process" ]; then
+      $bindir/babeltrace_thapi timeline $btt_common_flag -- $@
+    else
+      echo "Combinaison of $mode and $processing_mode not supported"
+      exit 1
     fi
 }
 
@@ -478,8 +482,15 @@ summary() {
             echo "$f is not a trace folder, we cannot replay. Exiting..."
             exit 1
         fi
+        if [[ "$f" == *"-aggreg"* ]]; then
+          processing_mode="on-the-fly"
+        elif [ $processing_mode = "on-the-fly" ]; then
+          echo "Cannot mix aggregate on non aggregate traces"
+          exit 1
+        fi
     done
-    bt2_all "$lttng_last_session"
+
+    call_babeltrace_thapi "$lttng_last_session"
 }
 
 #
@@ -487,9 +498,11 @@ summary() {
 #  |_ | \/ (/_
 #
 
-setub_babeltrace_live() {
-  mkdir -p $THAPI_LTTNG_O_ROOT
-  $bindir/babeltrace_thapi tally --live --backend <%= languages %> $bt_tally_argv -- "net://localhost/host/$(hostname)/THAPI_$(hostname)" > $THAPI_LTTNG_O_ROOT/tally_$(hostname)_$(hostname).log &
+setup_babeltrace_live() {
+  mkdir -p $THAPI_LTTNG_O
+  $bindir/babeltrace_thapi live2aggreg --backend <%= languages %> \
+                                       --inputs "net://localhost/host/$(hostname)/THAPI_$(hostname)"  \
+                                       --output $THAPI_LTTNG_O &
   BT_PID=$!
 }
 
@@ -504,12 +517,7 @@ trace_epilogue_live() {
         local new_output=${THAPI_LTTNG_O_ROOT/$(mpi_job_id)/$(date '+%Y%m%d-%H%M%S')}
         mv $THAPI_LTTNG_O_ROOT $new_output
         THAPI_LTTNG_O=$new_output
-
-        # All the traces have been moved. We can now print
-        for x in $(ls $THAPI_LTTNG_O/tally_*.log | sort -V || true); do
-           echo $x
-           cat $x
-        done
+        summary
     fi
 }
 
@@ -517,7 +525,7 @@ trace_and_summary_live() {
     [ "$#" -eq 0 ] && display_help
     # Each node will have their own lock
     run_iff_local_master setup_lttng --live
-    run_iff_local_master setub_babeltrace_live
+    run_iff_local_master setup_babeltrace_live
     local_barier setup
     # Create the metadata.
     # Read and dump `$LTTNG_UST_THAPI_METADATA` env
@@ -533,10 +541,15 @@ trace_and_summary_live() {
 # |_) _. ._ _ o ._   _     /\  ._ _
 # |  (_| | _> | | | (_|   /--\ | (_| \/
 #                    _|           _|
+[ "$#" -eq 0 ] && display_help
+
+# Minimal, Full, Default
 tracing_mode="default"
-procesing_mode="save"
 
-[ "$#" -eq 0 ] && display_help
+# Tally, Timeline, Trace
+mode="tally"
+# "Post-process" or "on-the-fly"
+processing_mode="post-process"
 
 debug=false
 bt_tally_argv=""
@@ -553,13 +566,13 @@ while (( "$#" )); do
         -k | --kernel-verbose)  shift; bt_tally_argv+=" --display_kernel_verbose=true" ;;
         -e | --extended)        shift; bt_tally_argv+=" --display=extended" ;;
         -r | --replay)          shift; replay=true ;;
-        -t | --trace)           shift; trace=true ;;
-        -l | --timeline)        shift; timeline=true ;;
+        -t | --trace)           shift; mode="trace" ;;
+        -l | --timeline)        shift; mode="timeline" ;;
         -j | --json)            shift; bt_tally_argv+=" --display_mode=json" ;;
         -m | --tracing-mode)    shift; tracing_mode=$1; shift ;;
         --no-profile)           shift; profile=false ;;
         --backend-level)        shift; bt_tally_argv+=" --backend_level=$1"; shift ;;
-        --no-save)              shift; procesing_mode="on-the-fly" ;;
+        --no-save)              shift; processing_mode="on-the-fly" ;;
         --traced-ranks)         shift; traced_ranks=$1; shift ;;
         --asm)                  shift; asm=true ;;
         --metadata)             shift; bt_tally_argv+=" --display_metadata=true" ;;
@@ -568,7 +581,7 @@ while (( "$#" )); do
         --clean-up)             shift; cleanup=true ;;
         --debug)                shift; debug=true ;;
         --)                     shift; break ;;
-        *)                      break  ;;
+        *)                      break ;;
     esac
 done
 
@@ -614,7 +627,7 @@ fi
 
 if [ $replay = true ]; then
     summary "$@"
-elif [ $procesing_mode = "save" ]; then
+elif [ $processing_mode = "post-process" ]; then
     trace_and_summary "$@"
 else
     trace_and_summary_live "$@"
diff --git a/ze/zeinterval_callbacks.cpp.erb b/ze/zeinterval_callbacks.cpp.erb
index 7d932dbb..d32e4ccf 100644
--- a/ze/zeinterval_callbacks.cpp.erb
+++ b/ze/zeinterval_callbacks.cpp.erb
@@ -193,20 +193,23 @@ size_t remove_memory(zeinterval_callbacks_state* state, hp_t hp, const uintptr_t
      auto &rs = state->rangeset_memory_shared[hp];
      auto its = rs.find(ptr);
      if (its != rs.end()) {
+          size_t tmp = its->second - its->first;
           rs.erase(its);
-          return its->second - its->first;
+          return tmp;
      }
      auto &rd = state->rangeset_memory_device[hp];
      auto itd = rd.find(ptr);
      if (itd != rd.end()) {
+          size_t tmp = itd->second - itd->first;
           rd.erase(itd);
-          return itd->second - itd->first;
+          return tmp;
      }
      auto &rh = state->rangeset_memory_host[hp];
      auto ith = rh.find(ptr);
      if (ith != rh.end()) {
+          size_t tmp = ith->second - ith->first;
           rh.erase(ith);
-          return ith->second - ith->first;
+          return tmp;
      }
      return 0;
 }