[ 
https://issues.apache.org/jira/browse/LUCENE-1410?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12801918#action_12801918
 ] 

Renaud Delbru commented on LUCENE-1410:
---------------------------------------

{quote}
Did you see any effect of the JIT? This is possible by making a loop that runs 
for about 1 second, and use that loop 3 times, see the output posting of 3 Oct 
2008. When the 2nd and 3rd time are just about equal one can assume that the 
JIT is done.
{quote}

I haven't seen the effect of the JIT on FOR.
I have re-performed the benchmark, repeating the decompression until the test 
time is superior to 300 ms or 1s (as it is done in 
TestFrameOfRef#doDecompPerfTestUsing() method), but I haven't observed a 
difference with the previous benchmark. 
In fact, it seems that it happens only for block size of 32, in the other 
cases, it seems imperceptible (in the previous benchmark, the number looks 
unstable, in the new benchmark however it looks more stable, but no significant 
increase between the first loop and the other ones).

In the first benchmark, I was not repeating the loop until 1 second is reached 
since there is no easy way to "reset" the reader. In the new benchmark, I am 
recreating the reader in the loop (which causes some overhead). Do you think it 
can have a consequence on the JIT ? 

{quote}
For the blocks that you've been measuring one might also see an effect of L1/L2 
data cache size.
{quote}

Yes, it should be an effect of the cache size. It was to check the increase of 
performance and find the optimal block size. This optimal block size may be 
dependent on my hardware (Intel(R) Core(TM)2 Duo CPU T7300  @ 2.00GHz, cache 
size : 4096 KB).

> PFOR implementation
> -------------------
>
>                 Key: LUCENE-1410
>                 URL: https://issues.apache.org/jira/browse/LUCENE-1410
>             Project: Lucene - Java
>          Issue Type: New Feature
>          Components: Other
>            Reporter: Paul Elschot
>            Priority: Minor
>         Attachments: autogen.tgz, LUCENE-1410-codecs.tar.bz2, 
> LUCENE-1410b.patch, LUCENE-1410c.patch, LUCENE-1410d.patch, 
> LUCENE-1410e.patch, TermQueryTests.tgz, TestPFor2.java, TestPFor2.java, 
> TestPFor2.java
>
>   Original Estimate: 21840h
>  Remaining Estimate: 21840h
>
> Implementation of Patched Frame of Reference.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


---------------------------------------------------------------------
To unsubscribe, e-mail: java-dev-unsubscr...@lucene.apache.org
For additional commands, e-mail: java-dev-h...@lucene.apache.org

Reply via email to