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  1. Lustre
  2. LU-17872

do not check reclaim full for every lock request

Details

    • Improvement
    • Resolution: Fixed
    • Minor
    • Lustre 2.16.0
    • None
    • None
    • 3
    • 9223372036854775807

    Description

      Checking reclaim full for every lock request is expensive - it require taking a global spinlock and takes up 10% of MDS CPU time under load, but is not necessary to do this check for every single lock request - it is OK if we very slightly exceed the reclaim limit. Instead, check it once for every 100 requests.  100 is chosen arbitrarily but should be sufficient for good performance.

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        Activity

          [LU-17872] do not check reclaim full for every lock request
          adilger Andreas Dilger made changes -
          Link New: This issue is related to DDN-5112 [ DDN-5112 ]
          pjones Peter Jones made changes -
          Fix Version/s New: Lustre 2.16.0 [ 15190 ]
          Resolution New: Fixed [ 1 ]
          Status Original: Open [ 1 ] New: Resolved [ 5 ]
          pjones Peter Jones added a comment -

          Merged for 2.16

          pjones Peter Jones added a comment - Merged for 2.16
          gerrit Gerrit Updater added a comment -

          "Oleg Drokin <green@whamcloud.com>" merged in patch https://review.whamcloud.com/c/fs/lustre-release/+/55141/
          Subject: LU-17872 ldlm: switch to read_positive in reclaim_full
          Project: fs/lustre-release
          Branch: master
          Current Patch Set:
          Commit: 0c16987b2233c32d775f0e3e6f6503c4b7825e02

          gerrit Gerrit Updater added a comment - "Oleg Drokin <green@whamcloud.com>" merged in patch https://review.whamcloud.com/c/fs/lustre-release/+/55141/ Subject: LU-17872 ldlm: switch to read_positive in reclaim_full Project: fs/lustre-release Branch: master Current Patch Set: Commit: 0c16987b2233c32d775f0e3e6f6503c4b7825e02
          adilger Andreas Dilger made changes -
          Comment [ The patch https://review.whamcloud.com/55141 "{{LU-17872 ldlm: switch to read_positive in reclaim_full}}" purports to improve mdtest performance significantly on many-core MDS nodes and should be investigated for backporting to b_es6_0. ]
          adilger Andreas Dilger made changes -
          Link New: This issue is related to EX-8604 [ EX-8604 ]
          paf Patrick Farrell (Inactive) added a comment - - edited

          "Patrick Farrell <paf0187@gmail.com>" merged in patch https://review.whamcloud.com/c/fs/lustre-release/+/55141
          Subject: LU-17872 ldlm: do not check reclaim full every time
          Project: fs/lustre-release
          Branch: master
          Current Patch Set:
          Commit: 6317ac084ab25ada52c5e18d5c76b89caffa83c9

          paf Patrick Farrell (Inactive) added a comment - - edited "Patrick Farrell <paf0187@gmail.com>" merged in patch https://review.whamcloud.com/c/fs/lustre-release/+/55141 Subject: LU-17872 ldlm: do not check reclaim full every time Project: fs/lustre-release Branch: master Current Patch Set: Commit: 6317ac084ab25ada52c5e18d5c76b89caffa83c9
          paf Patrick Farrell (Inactive) created issue -

          People

            paf Patrick Farrell (Inactive)
            paf Patrick Farrell (Inactive)
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            Dates

              Created:
              Updated:
              Resolved: