smp: Use bitwise operation to count cpu number
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Authored by aokblast on Jan 3 2026, 4:37 PM.

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rGe387d9438ba0: smp: Use bitwise operation to count cpu number

Summary

Previously, we iterated over all CPUs using CPU_FOREACH and checked
individual bits to count valid CPUs. Refactor this to use a bitwise AND
and popcount to count the number of enabled bits directly.

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rG FreeBSD src repository

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Event Timeline

aokblast created this revision.Jan 3 2026, 4:37 PM

Herald added subscribers: olce, imp. · View Herald TranscriptJan 3 2026, 4:37 PM

aokblast requested review of this revision.Jan 3 2026, 4:37 PM

Harbormaster completed remote builds in B69589: Diff 168958.Jan 3 2026, 4:37 PM

aokblast added a reviewer: markj.Jan 3 2026, 4:37 PM

markj accepted this revision.Jan 3 2026, 4:40 PM

This revision is now accepted and ready to land.Jan 3 2026, 4:40 PM

Thanks! Thought I sucessfully booted up on a AMD64 machine, this patch touches the basic logic of smp so I will think twice before landing it.

In D54474#1244841, @aokblast wrote:

Thanks! Thought I sucessfully booted up on a AMD64 machine, this patch touches the basic logic of smp so I will think twice before landing it.

It's probably ok, but yes it's a good idea to keep patches in a local tree that you test often. Then you can build some confidence in the changes before landing them.

Closed by commit rGe387d9438ba0: smp: Use bitwise operation to count cpu number (authored by aokblast). · Explain WhyWed, Feb 18, 9:42 AM

This revision was automatically updated to reflect the committed changes.

aokblast added a commit: rGe387d9438ba0: smp: Use bitwise operation to count cpu number.