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            I think that this work has been superceded by the developmentin LU-7990

            pjones Peter Jones added a comment - - edited I think that this work has been superceded by the developmentin LU-7990

            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.

            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.

            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

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              wc-triage WC Triage
              panda Andrew Perepechko
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                Updated:
                Resolved: