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Eliminate lock recursion from turnstiles.
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Authored by jeff on Dec 10 2019, 6:16 AM.
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Details

Summary

This avoids the one place we recursively lock turnstiles. In highly contended workloads the recursive locking actually imposes a performance penalty. We trade failed atomic cmpsets and multiple modifications to the lock cacheline for a few pointer comparisons.

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rS FreeBSD src repository - subversion
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Event Timeline

jeff added reviewers: jhb, kib, mav.
jeff set the repository for this revision to rS FreeBSD src repository - subversion.
This revision is now accepted and ready to land.Dec 10 2019, 2:42 PM
This revision was automatically updated to reflect the committed changes.
jeff added a commit: rS355782: schedlock 3/4.