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  1. MDEV-5864

Reduce usage of LOCK_open: TABLE_SHARE::tdc.free_tables

    Details

    • Type: Bug
    • Status: Closed
    • Priority: Major
    • Resolution: Fixed
    • Affects Version/s: 10.0.9
    • Fix Version/s: 10.0.10
    • Component/s: None
    • Labels:
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      Description

      tc_acquire_table and tc_release_table are critical sections of table cache. Among other things, they update TABLE_SHARE::tdc.free_tables:
      tc_acquire_table - pop TABLE object from free_tables
      tc_release_table - push TABLE object to free_tables

      Updating free_tables list is protected by global mutex. Since free_tables is per-share list we can protect it by per-share mutex instead.

      This is simple intermediate change that improves table cache scalability in many loads.

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              • Assignee:
                svoj Sergey Vojtovich
                Reporter:
                svoj Sergey Vojtovich
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