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  1. MariaDB Server
  2. MDEV-33588

buf::Block_hint is a performance hog

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    Description

      The class buf::Block_hint that was added in order to fix MDEV-23693 is an unnecessary performance hog that causes unnecessary lookups on buf_pool.page_hash.

      Originally, I was thinking that this function could be removed as part of rewriting the buffer pool resizing in MDEV-29445, but it turns out that we can do it independently of that. We only need to add a field btr_pcur_t::old_page_id to remember the page identifier where the persistent cursor position was stored, and pass this identifier to buf_page_optimistic_get(), which will have to perform a buf_pool.page_hash lookup anyway.

      Furthermore, in btr_pcur_optimistic_latch_leaves() we had better look up the current page normally, and perform some tricks to prevent a deadlock when acquiring a latch on the previous page, if needed. This will also allow us to simplify the function btr_pcur_move_backward_from_page().

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          causes

          Bug - A problem which impairs or prevents the functions of the product. MDEV-33946 mariadb-backup --prepare: Frequent [ERROR] InnoDB: OPT_PAGE_CHECKSUM mismatch on

          • Blocker - Blocks development and/or testing work, production could not run.
          • Closed
          relates to

          Bug - A problem which impairs or prevents the functions of the product. MDEV-33764 InnoDB: Failing assertion: err == DB_SUCCESS in btr0cur.cc line 4272

          • Major - Major loss of function.
          • Open

          Bug - A problem which impairs or prevents the functions of the product. MDEV-33819 The purge of committed history is mis-parsing some log

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-23693 Failing assertion: my_atomic_load32_explicit(&lock->lock_word, MY_MEMORY_ORDER_RELAXED) == X_LOCK_DECR

          • Blocker - Blocks development and/or testing work, production could not run.
          • Closed

          Task - A task that needs to be done. MDEV-29445 reorganise innodb buffer pool (and remove buffer pool chunks)

          • Critical - Crashes, loss of data, severe memory leak.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-33208 InnoDB: Trying to access update undo rec field 50 in index `PRIMARY` of table NNN but index has only 14 fields

          • Major - Major loss of function.
          • Closed

          Activity

            Transition Time In Source Status Execution Times
            Marko Mäkelä made transition -
            Open In Progress
            		11s 1
            Marko Mäkelä made transition -
            Stalled In Progress
            		57m 37s 1
            Marko Mäkelä made transition -
            In Progress In Review
            		2h 2
            Debarun Banerjee made transition -
            In Review Stalled
            		30d 11h 36m 2
            Marko Mäkelä made transition -
            Stalled Closed
            		5d 3h 29m 1

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              marko Marko Mäkelä
              marko Marko Mäkelä
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              Dates

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                Updated:
                Resolved:

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