Uploaded image for project: 'JikesRVM'
  1. JikesRVM
  2. RVM-884

MMTk stats can be hard for humans to read

    Details

    • Type: Improvement
    • Status: Open
    • Priority: Low
    • Resolution: Unresolved
    • Affects Version/s: 3.1.0
    • Fix Version/s: 3.1.5
    • Component/s: MMTk
    • Labels:
      None

      Description

      MMTk attempts to print its statistics in a single row like so:

      {{
      ============================ MMTk Statistics Totals ============================
      GC time.mu time.gc perf.mu perf.gc refType scan finalize prepare precopy stacks root forward release init finish L1I_MISSES.mu L1I_MISSES.gc
      7 6751.76 5881.21 0 0 99.35 5038.20 22.58 0.28 0.92 4.99 713.75 0.00 0.65 0.12 0.14 2330019756995 1443109010784
      Total time: 12632.98 ms
      ------------------------------ End MMTk Statistics -----------------------------
      }}

      Hopefully the problems with this approach are clear to see from a human readers perspective: i) Headers do not always line up with values, ii) It's even harder to read with many counters as the output becomes wider than your terminal

      Attached is a trivial patch that instead prints one statistic per line, like so:

      {{
      ============================ MMTk Statistics Totals ============================
      GC: 7
      time.mu: 6872.53
      time.gc: 5854.95
      perf.mu: 0
      perf.gc: 0
      refType: 101.65
      scan: 5008.27
      finalize: 22.64
      prepare: 0.30
      precopy: 0.89
      stacks: 4.79
      root: 715.20
      forward: 0.00
      release: 0.66
      init: 0.16
      finish: 0.18
      L1I_MISSES.mu: 1569810545957(SCALED)
      L1I_MISSES.gc: 951335255621(SCALED)
      Total time: 12727.48 ms
      ------------------------------ End MMTk Statistics -----------------------------
      }}

      As a human I certainly prefer the second output, however I have no idea how many scripts this change would break. If a consensus can be reached and more human readability is desired then perhaps this patch can be applied.

      This work is motivated by another patch that I am about to submit that increases the number of statistics MMTk reports (thus increasing problems of wide output)

      Kind regards
      Laurence

        Attachments

          Activity

            People

            • Assignee:
              Unassigned
              Reporter:
              l.hellyer@kent.ac.uk Laurence Hellyer
            • Votes:
              0 Vote for this issue
              Watchers:
              1 Start watching this issue

              Dates

              • Created:
                Updated: