Details
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Bug
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Status: Closed (View Workflow)
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Critical
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Resolution: Fixed
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10.11, 11.0, 11.1, 11.2, 11.3
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GNU/Linux, various multi socket Intel CPU systems (NUMA)
Description
In MDEV-25341 (MariaDB Server 10.11.0), some calls to madvise() with MADV_FREE were added.
If the call in buf_LRU_block_free_non_file_page() is committed out, the throughput in an I/O bound HammerDB benchmark would improve by 6% to 18%, depending on the CPU microarchitecture.
It could be best to revert this code for now. A better solution might be doable as part of a larger refactoring (MDEV-25340, MDEV-29445). Instead of invoking madvise(MADV_FREE) on individual buffer pages, we might invoke it on larger chunks at a time. There could also be an explicit SQL statement for defragmenting or freeing the buffer pool.
Attachments
Issue Links
- is blocked by
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MDEV-24670 avoid OOM by linux kernel co-operative memory management
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- Closed
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- is caused by
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MDEV-25341 innodb buffer pool soft decommit of memory
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- Closed
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- relates to
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MDEV-34863 RAM Usage Changed Significantly Between 10.11 Releases
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- Open
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