Details
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Bug
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Status: Closed (View Workflow)
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Blocker
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Resolution: Fixed
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10.3.4
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None
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10.1.31
Description
Issue described in https://lists.launchpad.net/maria-discuss/msg04975.html as follows
"
On a 4-core (4 physical, 8 logical cores), 3.5 Ghz box, MariaDB 10.3.4
consumes typically 35-40% of available CPU even when completely idle
according to Task Manager. Please see image.
I cannot tell if previous 10.3 versions also did, as I don't have 10.3
running constantly in the backgorund. I just observed this now. This does
not happen with MariaDB 10.1, MariaDB 10.2, MySQL 5.6, MySQL 5.7 and MySQL
8.0 (all those I have starting with Windows on this box), where the
CPU-load is neglible unless the server is "doing real work". As a result, the CPU clock frequency is always highest possible 3.5 Ghz
(this CPU model is a 4th generation Intel with the option to scale down CPU
frequency to around 40-50% of max. when there is no need for more) when
MariaDB 10.3.4 is running.
"
Examination of the attached stacktraces taken from the process when it in this "idle" state, shows 3 CPUs being occupied by something, that for most time seems to be some busy-look acquiring innodb mutex
.
my.ini uses all defaults, with the exception of
innodb_buffer_pool_size=4091M
Setting innodb_page_cleaners = 1, according to reporter, fixed the issue.
Relevant callstack information :
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. 15 Id: 2ce8.2d38 Suspend: 0 Teb: 0000005f`55863000 Unfrozen
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Start: mysqld!buf_flush_page_cleaner_worker (00007ff7`6aec9370)
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Priority: 0 Priority class: 32 Affinity: ff
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Child-SP RetAddr Call Site
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0000005f`56cffd40 00007ff7`6aec945d ntdll!RtlLeaveCriticalSection+0x29
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0000005f`56cffd70 00007ffa`6d831fe4 mysqld!buf_flush_page_cleaner_worker+0xed [d:\winx64-packages\build\src\storage\innobase\buf\buf0flu.cc @ 3574]
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0000005f`56cffdb0 00007ffa`6ff0efb1 kernel32!BaseThreadInitThunk+0x14
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0000005f`56cffde0 00000000`00000000 ntdll!RtlUserThreadStart+0x21
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. 16 Id: 2ce8.2d3c Suspend: 0 Teb: 0000005f`55865000 Unfrozen
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Start: mysqld!buf_flush_page_cleaner_worker (00007ff7`6aec9370)
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Priority: 0 Priority class: 32 Affinity: ff
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Child-SP RetAddr Call Site
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0000005f`56dff6c0 00007ff7`6aec8503 mysqld!PolicyMutex<TTASEventMutex<GenericPolicy> >::enter+0x26 [d:\winx64-packages\build\src\storage\innobase\include\ib0mutex.h @ 622]
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0000005f`56dff740 00007ff7`6aec944b mysqld!pc_flush_slot+0x43 [d:\winx64-packages\build\src\storage\innobase\buf\buf0flu.cc @ 2841]
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0000005f`56dff7b0 00007ffa`6d831fe4 mysqld!buf_flush_page_cleaner_worker+0xdb [d:\winx64-packages\build\src\storage\innobase\buf\buf0flu.cc @ 3574]
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0000005f`56dff7f0 00007ffa`6ff0efb1 kernel32!BaseThreadInitThunk+0x14
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0000005f`56dff820 00000000`00000000 ntdll!RtlUserThreadStart+0x21
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. 17 Id: 2ce8.2d40 Suspend: 0 Teb: 0000005f`55867000 Unfrozen
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Start: mysqld!buf_flush_page_cleaner_worker (00007ff7`6aec9370)
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Priority: 0 Priority class: 32 Affinity: ff
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Child-SP RetAddr Call Site
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0000005f`56eff750 00007ff7`6aec8503 mysqld!PolicyMutex<TTASEventMutex<GenericPolicy> >::enter+0x57 [d:\winx64-packages\build\src\storage\innobase\include\ib0mutex.h @ 635]
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0000005f`56eff7d0 00007ff7`6aec944b mysqld!pc_flush_slot+0x43 [d:\winx64-packages\build\src\storage\innobase\buf\buf0flu.cc @ 2841]
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0000005f`56eff840 00007ffa`6d831fe4 mysqld!buf_flush_page_cleaner_worker+0xdb [d:\winx64-packages\build\src\storage\innobase\buf\buf0flu.cc @ 3574]
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0000005f`56eff880 00007ffa`6ff0efb1 kernel32!BaseThreadInitThunk+0x14
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0000005f`56eff8b0 00000000`00000000 ntdll!RtlUserThreadStart+0x21
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. 18 Id: c10.1c30 Suspend: 0 Teb: 00000012`c5100000 Unfrozen
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Start: mysqld!buf_flush_page_cleaner_worker (00007ff7`6aec9370)
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Priority: 0 Priority class: 32 Affinity: ff
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Child-SP RetAddr Call Site
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00000012`c63ff970 00007ffa`6d831fe4 mysqld!buf_flush_page_cleaner_worker+0xe8 [d:\winx64-packages\build\src\storage\innobase\buf\buf0flu.cc @ 3574]
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00000012`c63ff9b0 00007ffa`6ff0efb1 kernel32!BaseThreadInitThunk+0x14
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00000012`c63ff9e0 00000000`00000000 ntdll!RtlUserThreadStart+0x21
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. 19 Id: c10.a04 Suspend: 0 Teb: 00000012`c5102000 Unfrozen
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Start: mysqld!buf_flush_page_cleaner_worker (00007ff7`6aec9370)
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Priority: 0 Priority class: 32 Affinity: ff
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Child-SP RetAddr Call Site
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00000012`c64ff6d0 00007ff7`6ae0ef0f ntdll!RtlEnterCriticalSection+0x13
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(Inline Function) --------`-------- mysqld!OSMutex::enter+0xa [d:\winx64-packages\build\src\storage\innobase\include\sync0types.h @ 468]
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00000012`c64ff700 00007ff7`6aec945d mysqld!os_event::wait_low+0x1f [d:\winx64-packages\build\src\storage\innobase\os\os0event.cc @ 330]
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00000012`c64ff730 00007ffa`6d831fe4 mysqld!buf_flush_page_cleaner_worker+0xed [d:\winx64-packages\build\src\storage\innobase\buf\buf0flu.cc @ 3574]
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00000012`c64ff770 00007ffa`6ff0efb1 kernel32!BaseThreadInitThunk+0x14
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00000012`c64ff7a0 00000000`00000000 ntdll!RtlUserThreadStart+0x21
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. 20 Id: c10.161c Suspend: 0 Teb: 00000012`c5104000 Unfrozen
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Start: mysqld!buf_flush_page_cleaner_worker (00007ff7`6aec9370)
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Priority: 0 Priority class: 32 Affinity: ff
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Child-SP RetAddr Call Site
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00000012`c65ff9e8 00007ffa`6feec17f ntdll!NtWaitForAlertByThreadId+0x14
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00000012`c65ff9f0 00007ffa`6feebf4b ntdll!RtlpWaitOnAddressWithTimeout+0x43
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00000012`c65ffa20 00007ffa`6fec0c49 ntdll!RtlpWaitOnCriticalSection+0x15f
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00000012`c65ffad0 00007ffa`6fec0b60 ntdll!RtlpEnterCriticalSectionContended+0xd9
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00000012`c65ffb00 00007ff7`6ae0ef0f ntdll!RtlEnterCriticalSection+0x40
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(Inline Function) --------`-------- mysqld!OSMutex::enter+0xa [d:\winx64-packages\build\src\storage\innobase\include\sync0types.h @ 468]
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00000012`c65ffb30 00007ff7`6aec945d mysqld!os_event::wait_low+0x1f [d:\winx64-packages\build\src\storage\innobase\os\os0event.cc @ 330]
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00000012`c65ffb60 00007ffa`6d831fe4 mysqld!buf_flush_page_cleaner_worker+0xed [d:\winx64-packages\build\src\storage\innobase\buf\buf0flu.cc @ 3574]
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00000012`c65ffba0 00007ffa`6ff0efb1 kernel32!BaseThreadInitThunk+0x14
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00000012`c65ffbd0 00000000`00000000 ntdll!RtlUserThreadStart+0x21
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Attachments
Issue Links
- is caused by
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MDEV-11025 Make number of page cleaner threads variable dynamic
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- Closed
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- relates to
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MDEV-15053 Reduce buf_pool_t::mutex contention
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- Closed
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MDEV-15058 Remove multiple InnoDB buffer pool instances
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- Closed
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MDEV-9784 High CPU Usage When Absolutely Idle on OSX
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- Closed
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MDEV-11738 Mariadb uses 100% of several of my 8 cpus doing nothing
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- Closed
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