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  1. Lustre
  2. LU-13669

improve mmap performances

Details

    • Improvement
    • Resolution: Fixed
    • Minor
    • Lustre 2.14.0
    • None
    • None
    • 9223372036854775807

    Description

      We have observed slow performance on mmap read on some applications.

      The problem is if access pattern is neither sequential nor stride reading, but
      still adjacent in a small range and then seek a random position.

      So the pattern could be something like this:

      [1M data] [hole..] [0.5M data] [hole]......[0.7M data]......[1M data]

      So every time application want to access some data, the data is not only 4K but
      cosed to let's say 1M range, so if we could predict this kind of behavior and next time we hit page miss, we use last time range for prefetching.

      Attachments

        Issue Links

          is related to

          Improvement - An improvement or enhancement to an existing feature or task. LUDOC-485 document llite.*.read_ahead_range_kb parameter

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Open
          is related to

          Improvement - An improvement or enhancement to an existing feature or task. LU-11416 Improve readahead for random read of small/medium files

          • Minor - Minor loss of function, or other problem where easy workaround is present.
          • Open

          Activity

            [LU-13669] improve mmap performances
            adilger Andreas Dilger made changes -
            Link New: This issue is related to LU-11416 [ LU-11416 ]
            pjones Peter Jones made changes -
            Link Original: This issue is related to JFC-10 [ JFC-10 ]
            adilger Andreas Dilger made changes -
            Fix Version/s New: Lustre 2.14.0 [ 14490 ]
            wshilong Wang Shilong (Inactive) made changes -
            Resolution New: Fixed [ 1 ]
            Status Original: Open [ 1 ] New: Resolved [ 5 ]
            adilger Andreas Dilger made changes -
            Link New: This issue is related to DDN-1769 [ DDN-1769 ]
            adilger Andreas Dilger made changes -
            Link New: This issue is related to LUDOC-485 [ LUDOC-485 ]
            sihara Shuichi Ihara made changes -
            Link New: This issue is related to EX-764 [ EX-764 ]
            pjones Peter Jones made changes -
            Link New: This issue is related to JFC-10 [ JFC-10 ]
            wshilong Wang Shilong (Inactive) made changes -
            Assignee Original: WC Triage [ wc-triage ] New: Wang Shilong [ wshilong ]
            wshilong Wang Shilong (Inactive) made changes -
            Link New: This issue is related to NVDA-29 [ NVDA-29 ]
            wshilong Wang Shilong (Inactive) created issue -

            People

              wshilong Wang Shilong (Inactive)
              wshilong Wang Shilong (Inactive)
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              Dates

                Created:
                Updated:
                Resolved: