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Use a large kmem arena import size on NUMA systems.
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Authored by markj on Aug 12 2020, 9:11 PM.

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Summary

This helps minimize the fragmentation that occurs when 2MB imports are
interleaved across NUMA domains. This complements D24548, which aims to
reduce internal fragmentation caused by vmem's unwillingness to coalesce
across imported spans.

This is based upon the presumption that potential overallocation is not
harmful on NUMA systems, i.e., we are at worst wasting page table pages
used to extend the kernel pmap.

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Repository
rS FreeBSD src repository
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Event Timeline

markj requested review of this revision.Aug 12 2020, 9:11 PM
markj created this revision.

With this and the other vmem diff we get much better superpage usage in the kernel map during poudriere runs.

This revision is now accepted and ready to land.Aug 14 2020, 8:05 PM
This revision was automatically updated to reflect the committed changes.