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  1. MariaDB Server
  2. MDEV-24142

rw_lock_t has unnecessarily complex wait logic

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    Description

      The InnoDB custom implementation of a read-write latch (rw_lock_t) encapsulates two os_event_t. Both os_event_t encapsulate a mutex and a condition variable. One mutex would suffice. There also are some data fields to control the waiting, although the rw_lock_t::lock_word alone is sufficient for that.

      As part of MDEV-21452, we would replace all os_event_t with condition variables. Simplifying the read-write latch implementation is a prerequisite for that.

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          blocks

          Bug - A problem which impairs or prevents the functions of the product. MDEV-14659 Innodb scalibility issue found in Mariadb code for complex 'select' queries in Arm platform

          • Major - Major loss of function.
          • Closed

          Task - A task that needs to be done. MDEV-18976 Implement a CHECKSUM redo log record for improved validation

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-21452 Use condition variables and normal mutexes instead of InnoDB os_event and mutex

          • Major - Major loss of function.
          • Closed
          causes

          Bug - A problem which impairs or prevents the functions of the product. MDEV-24642 Assertion `r->emplace(pthread_self()).second' failed in sux_lock<srw>::s_lock_register()

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-24643 Assertion `(l & (WRITER | UPDATER)) == UPDATER' failed in void rw_lock::update_unlock()

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-24834 Assertion `mtr->memo_contains_flagged( &index->lock, MTR_MEMO_S_LOCK)' failed in btr_cur_search_to_nth_level_func

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-25512 Deadlock between sux_lock::u_x_upgrade() and sux_lock::u_lock()

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-29336 mysqld: storage/innobase/include/sux_lock.h:404: void sux_lock<ssux>::u_x_upgrade() [with ssux = ssux_lock_impl<true>]: Assertion `have_u_not_x()' failed.

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

          Bug - A problem which impairs or prevents the functions of the product. MDEV-33855 MSAN use-of-uninitialized-value in rtr_pcur_getnext_from_path()

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

          Bug - A problem which impairs or prevents the functions of the product. MDEV-24167 InnoDB unnecessarily uses complex rw-lock implementation

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-24240 Pessimistic operations on SPATIAL INDEX wrongly release page latches

          • Major - Major loss of function.
          • Open
          relates to

          Task - A task that needs to be done. MDEV-7109 Add support for INFORMATION_SCHEMA.INNODB_SEMAPHORE_WAITS

          • Major - Major loss of function.
          • Closed

          Task - A task that needs to be done. MDEV-7399 Add support for INFORMATION_SCHEMA.INNODB_MUTEXES

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

          Bug - A problem which impairs or prevents the functions of the product. MDEV-24410 Deadlock between freeing and allocating undo pages

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-24786 Assertion `!have_x()' failed in sux_lock<srw>::s_lock() [with srw = ssux_lock_low]

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-25267 Reported latching order violation in ibuf_remove_free_page()

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-26467 Unnecessary compare-and-swap loop in futex-based synchronization

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-27058 Buffer page descriptors are too large

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-34759 buf_page_get_low() is unnecessarily acquiring exclusive latch on secondary index pages

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

          Bug - A problem which impairs or prevents the functions of the product. MDEV-15798 Mutex leak on accessing INFORMATION_SCHEMA.INNODB_MUTEXES

          • Major - Major loss of function.
          • Closed

          Bug - A problem which impairs or prevents the functions of the product. MDEV-21330 Lock monitor doesn't print a semaphore's last reserved thread in non-debug builds and INFORMATION_SCHEMA.INNODB_SYS_SEMAPHORE_WAITS is totally broken

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

          Bug - A problem which impairs or prevents the functions of the product. MDEV-24630 MY_RELAX_CPU assembly instruction upgrade/research for memory barrier on ARM

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

          Bug - A problem which impairs or prevents the functions of the product. MDEV-25404 read-only performance regression in 10.6

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

          Task - A task that needs to be done. MDEV-32065 Always check whether lock is free at first to optimize InnoDB mutexes

          • Major - Major loss of function.
          • Open

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              marko Marko Mäkelä
              marko Marko Mäkelä
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