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  1. Lustre
  2. LU-7140

Few 4 MB BRW rpcs from readahead path

Details

    • Improvement
    • Resolution: Won't Fix
    • Minor
    • None
    • None
    • 9223372036854775807

    Description

      We have found that setting osc.max_pages_per_rpc=1024 leads to few 4 MB BRW rpcs.

      More details and a patch will be uploaded shortly.

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        Issue Links

          is related to

          New Feature - A new feature of the product, which has yet to be developed. LU-7990 Large bulk IO support

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

          Activity

            [LU-7140] Few 4 MB BRW rpcs from readahead path
            pjones Peter Jones added a comment - - edited

            I think that this work has been superceded by the developmentin LU-7990

            pjones Peter Jones added a comment - - edited I think that this work has been superceded by the developmentin LU-7990
            panda Andrew Perepechko added a comment -

            James, since so many people requested to make the step automatic, I updated the patch according to Jinshan Xiong's proposal.

            panda Andrew Perepechko added a comment - James, since so many people requested to make the step automatic, I updated the patch according to Jinshan Xiong's proposal.
            simmonsja James A Simmons added a comment -

            I have to ask what is the advantage of making read ahead step size configurable? Wouldn't be simpler to just adjust the read ahead step to be based on max_pages_per_rpc instead. Also if their is a benefit to making the read ahead step configurable why in megabytes. I think it would be better in pages. Especially since user can pass in strange values that end up having to be rounded to the nearest page anyways.

            simmonsja James A Simmons added a comment - I have to ask what is the advantage of making read ahead step size configurable? Wouldn't be simpler to just adjust the read ahead step to be based on max_pages_per_rpc instead. Also if their is a benefit to making the read ahead step configurable why in megabytes. I think it would be better in pages. Especially since user can pass in strange values that end up having to be rounded to the nearest page anyways.
            gerrit Gerrit Updater added a comment -

            Andrew Perepechko (andrew.perepechko@seagate.com) uploaded a new patch: http://review.whamcloud.com/16374
            Subject: LU-7140: configurable readahead step
            Project: fs/lustre-release
            Branch: master
            Current Patch Set: 1
            Commit: 500cc2eac76d1c24f807aa5faf4344a3372e5585

            gerrit Gerrit Updater added a comment - Andrew Perepechko (andrew.perepechko@seagate.com) uploaded a new patch: http://review.whamcloud.com/16374 Subject: LU-7140 : configurable readahead step Project: fs/lustre-release Branch: master Current Patch Set: 1 Commit: 500cc2eac76d1c24f807aa5faf4344a3372e5585

            People

              wc-triage WC Triage
              panda Andrew Perepechko
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              Dates

                Created:
                Updated:
                Resolved: