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

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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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Repository

rG FreeBSD src repository

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No Test Coverage

Build Status

Buildable 69589
Build 66472: arc lint + arc unit

Event Timeline

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

Herald added subscribers: olce, imp. · View Herald TranscriptSat, Jan 3, 4:37 PM

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

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

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

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

This revision is now accepted and ready to land.Sat, Jan 3, 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.

Revision Contents
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sys/

kern/

subr_smp.c

8 lines

Diff 168958

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smp: Use bitwise operation to count cpu numberAcceptedPublicActions