Uploaded image for project: 'Lustre'
  1. Lustre
  2. LU-14958

configurable hash table size for jbd2

    XMLWordPrintable

Details

    • Improvement
    • Resolution: Fixed
    • Minor
    • Lustre 2.16.0, Lustre 2.15.3
    • None
    • None
    • 9223372036854775807

    Description

      revoke hash table can be enourmous with multi-GB journal. this may result in millions of revoke records which are loaded and inserted into specific hashtable during journal replay.
      currently the revoke hashtable's size is hard-coded as 256, thus every slot may get too many records.

      a simple benchmark of that code:
      1048576 - 95 seconds
      2097152 - 580 seconds
      in the fields it can be upto 30M records to find/insert.

      with 8192 buckets in the hash table:
      4194304 - 59 seconds
      8388608 - 247 seconds

      Attachments

        1. jbd2_debugfs.gz
          106.24 MB
        2. dumpe2fs.txt
          2 kB

        Issue Links

          Activity

            People

              bzzz Alex Zhuravlev
              bzzz Alex Zhuravlev
              Votes:
              0 Vote for this issue
              Watchers:
              9 Start watching this issue

              Dates

                Created:
                Updated:
                Resolved: