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Posted to commits@cassandra.apache.org by "Ariel Weisberg (JIRA)" <ji...@apache.org> on 2015/01/14 00:15:35 UTC
[jira] [Comment Edited] (CASSANDRA-8614) Select optimal CRC32
implementation at runtime
[ https://issues.apache.org/jira/browse/CASSANDRA-8614?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14276146#comment-14276146 ]
Ariel Weisberg edited comment on CASSANDRA-8614 at 1/13/15 11:14 PM:
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Compiles on Java 7 and when run on Java 8 you get the intrinsic. There is a test case to validate that the two checksum implementations behave the same.
was (Author: aweisberg):
Compiles on Java 7 and when run on Java 8 you get the intrinsic. There is a test case to validate that the two checksums implementations behave the same.
> Select optimal CRC32 implementation at runtime
> ----------------------------------------------
>
> Key: CASSANDRA-8614
> URL: https://issues.apache.org/jira/browse/CASSANDRA-8614
> Project: Cassandra
> Issue Type: Improvement
> Components: Core
> Reporter: Ariel Weisberg
> Labels: performance
> Attachments: 8614.patch, CRC32FactoryTest.java
>
>
> JDK 8 has support for an intrinsic for CRC32 that runs at 12-13 gigabytes/sec per core in my quick and dirty test. PureJavaCRC32 is < 800 megabytes/sec if I recall and it has a lookup table that evicts random cache lines every time it runs.
> In order to capture the benefit of that when it is available we can select a CRC32 implementation at startup in a static block.
> If JDK 8 is not what is running we can fall back to the existing PureJavaCRC32 implementation.
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