You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@cassandra.apache.org by "Robert Stupp (JIRA)" <ji...@apache.org> on 2016/12/12 14:53:58 UTC
[jira] [Updated] (CASSANDRA-13034) Move to FastThreadLocalThread
and FastThreadLocal
[ https://issues.apache.org/jira/browse/CASSANDRA-13034?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Robert Stupp updated CASSANDRA-13034:
-------------------------------------
Fix Version/s: 3.x
Status: Patch Available (was: Open)
||cassandra-3.X|[branch|https://github.com/apache/cassandra/compare/cassandra-3.X...snazy:13034-fast-thread-local-thread-3.X]|[testall|http://cassci.datastax.com/view/Dev/view/snazy/job/snazy-13034-fast-thread-local-thread-3.X-testall/lastSuccessfulBuild/]|[dtest|http://cassci.datastax.com/view/Dev/view/snazy/job/snazy-13034-fast-thread-local-thread-3.X-dtest/lastSuccessfulBuild/]
||trunk|[branch|https://github.com/apache/cassandra/compare/trunk...snazy:13034-fast-thread-local-thread-trunk]|[testall|http://cassci.datastax.com/view/Dev/view/snazy/job/snazy-13034-fast-thread-local-thread-trunk-testall/lastSuccessfulBuild/]|[dtest|http://cassci.datastax.com/view/Dev/view/snazy/job/snazy-13034-fast-thread-local-thread-trunk-dtest/lastSuccessfulBuild/]
> Move to FastThreadLocalThread and FastThreadLocal
> -------------------------------------------------
>
> Key: CASSANDRA-13034
> URL: https://issues.apache.org/jira/browse/CASSANDRA-13034
> Project: Cassandra
> Issue Type: Bug
> Reporter: Robert Stupp
> Assignee: Robert Stupp
> Fix For: 3.x
>
>
> (Supersedes/includes CASSANDRA-13033 for 3.X & trunk)
> We still use {{ThreadLocal}} in a couple of places, so I was curious how much faster {{FastThreadLocal}} is compared to {{ThreadLocal}}. A micro bench tells, that {{FastThreadLocal}} has a runtime of ~2.7ns and {{ThreadLocal}} of ~4.7ns - about 2ns slower (EDIT: subtracted baseline).
> However, looking at the implementations it seems that {{ThreadLocal}} has more dependent pointer gets than {{FastThreadLocal}}. This (CPU cache misses) is not reflected in the artificial benchmark below.
> The patch migrates all {{Thread}} instances (except a few in tests) and all {{ThreadLocal}} instances.
> {code:title=FastThreadLocalBench with 4 threads on 4 core CPU}
> [java] FastThreadLocalBench.baseline 2 avgt 5 3.023 ± 0.081 ns/op
> [java] FastThreadLocalBench.fastThreadLocal 2 avgt 5 5.610 ± 0.154 ns/op
> [java] FastThreadLocalBench.fastThreadLocal 4 avgt 5 5.653 ± 0.042 ns/op
> [java] FastThreadLocalBench.fastThreadLocal 8 avgt 5 5.763 ± 0.588 ns/op
> [java] FastThreadLocalBench.fastThreadLocal 12 avgt 5 5.673 ± 0.117 ns/op
> [java] FastThreadLocalBench.threadLocal 2 avgt 5 7.708 ± 0.723 ns/op
> [java] FastThreadLocalBench.threadLocal 4 avgt 5 7.604 ± 0.059 ns/op
> [java] FastThreadLocalBench.threadLocal 8 avgt 5 7.629 ± 0.080 ns/op
> [java] FastThreadLocalBench.threadLocal 12 avgt 5 7.858 ± 0.483 ns/op
> {code}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)