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MDEV-24789: Reduce lock_sys.wait_mutex contention

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A performance regression was introduced by
commit e71e613353 (MDEV-24671)
and mostly addressed by
commit 455514c800.

The regression is likely caused by increased contention
lock_sys.latch (former lock_sys.mutex), possibly indirectly
caused by contention on lock_sys.wait_mutex. This change aims to
reduce both, but further improvements will be needed.

lock_wait(): Minimize the lock_sys.wait_mutex hold time.

lock_sys_t::deadlock_check(): Add a parameter for indicating
whether lock_sys.latch is exclusively locked.

trx_t::was_chosen_as_deadlock_victim: Always use atomics.

lock_wait_wsrep(): Assume that no mutex is being held.

Deadlock::report(): Always kill the victim transaction.

lock_sys_t::timeout: New counter to back MONITOR_TIMEOUT.
This commit is contained in:
Marko Mäkelä
2021-02-26 14:52:51 +02:00
parent d9898c9a71
commit 7cf4419fc4
8 changed files with 173 additions and 165 deletions
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2
mysql-test/suite/innodb/r/innodb_skip_innodb_is_tables.result
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@ -40,7 +40,7 @@ metadata_table_handles_opened metadata 0 NULL NULL NULL 0 NULL NULL NULL NULL NU
metadata_table_handles_closed metadata 0 NULL NULL NULL 0 NULL NULL NULL NULL NULL NULL NULL 0 counter Number of table handles closed
metadata_table_reference_count metadata 0 NULL NULL NULL 0 NULL NULL NULL NULL NULL NULL NULL 0 counter Table reference counter
lock_deadlocks lock 0 NULL NULL NULL 0 NULL NULL NULL NULL NULL NULL NULL 0 value Number of deadlocks
lock_timeouts lock 0 NULL NULL NULL 0 NULL NULL NULL NULL NULL NULL NULL 0 counter Number of lock timeouts
lock_timeouts lock 0 NULL NULL NULL 0 NULL NULL NULL NULL NULL NULL NULL 0 value Number of lock timeouts
lock_rec_lock_waits lock 0 NULL NULL NULL 0 NULL NULL NULL NULL NULL NULL NULL 0 counter Number of times enqueued into record lock wait queue
lock_table_lock_waits lock 0 NULL NULL NULL 0 NULL NULL NULL NULL NULL NULL NULL 0 counter Number of times enqueued into table lock wait queue
lock_rec_lock_requests lock 0 NULL NULL NULL 0 NULL NULL NULL NULL NULL NULL NULL 0 counter Number of record locks requested