rmlock: Micro-optimize read locking
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Authored by markj on Feb 25 2022, 3:51 PM.

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Reviewers

mjg
jah

Commits

rGc84bb8cd771c: rmlock: Micro-optimize read locking

Summary

Use get_pcpu() instead of an open-coded pcpu_find(td->td_oncpu). This
eliminates some unneccessary memory accesses and on amd64 results in a
shorter instruction sequence. Note that get_pcpu() didn't exist when
rmlocks were added.

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Repository

rS FreeBSD src repository - subversion

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Lint Passed

Unit

No Test Coverage

Build Status

Buildable 44577
Build 41465: arc lint + arc unit

Event Timeline

markj created this revision.Feb 25 2022, 3:51 PM

Herald added a subscriber: imp. · View Herald TranscriptFeb 25 2022, 3:51 PM

markj requested review of this revision.Feb 25 2022, 3:51 PM

Harbormaster completed remote builds in B44577: Diff 103230.Feb 25 2022, 3:51 PM

mjg accepted this revision.Feb 25 2022, 3:54 PM

This revision is now accepted and ready to land.Feb 25 2022, 3:54 PM

please mfc this to stable/12

jah accepted this revision.Feb 25 2022, 5:15 PM

Closed by commit rGc84bb8cd771c: rmlock: Micro-optimize read locking (authored by markj). · Explain WhyFeb 25 2022, 6:58 PM

This revision was automatically updated to reflect the committed changes.

markj added a commit: rGc84bb8cd771c: rmlock: Micro-optimize read locking.

markj added a reverting change: rGafb44cb01018: rmlock: Temporarily revert commit c84bb8cd771c.Mar 7 2022, 3:44 PM

markj added a reverting change: rG4a80132dcd48: rmlock: Temporarily revert commit c84bb8cd771c.Mar 7 2022, 3:47 PM

markj added a reverting change: rGea683b4bae98: rmlock: Temporarily revert commit c84bb8cd771c.

Revision Contents
Changeset List

Path

Size

sys/

kern/

kern_rmlock.c

4 lines

Diff 103230

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rmlock: Micro-optimize read lockingClosedPublicActions