hadoop-mapreduce-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Todd Lipcon (JIRA)" <j...@apache.org>
Subject [jira] [Created] (MAPREDUCE-4274) MapOutputBuffer should use native byte order for kvmeta
Date Sun, 20 May 2012 21:44:41 GMT
Todd Lipcon created MAPREDUCE-4274:

             Summary: MapOutputBuffer should use native byte order for kvmeta
                 Key: MAPREDUCE-4274
                 URL: https://issues.apache.org/jira/browse/MAPREDUCE-4274
             Project: Hadoop Map/Reduce
          Issue Type: Improvement
          Components: performance, task
    Affects Versions: 2.0.0
            Reporter: Todd Lipcon
            Assignee: Todd Lipcon
            Priority: Minor

I don't have a benchmark to support this, but this should give a small CPU improvement on
the map output buffer: currently, we create {{kvmeta}} as {{ByteBuffer.wrap(kvbuffer).asIntBuffer()}}.
According to the javadocs, the resulting int buffer will inherit its byte order from the ByteBuffer
it comes from, and the byte buffer defaults to BIG_ENDIAN. Thus, all of our int access to/from
the buffer will require byte-swapping.

This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira


View raw message