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https://issues.apache.org/jira/browse/COUCHDB-798?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12932169#action_12932169
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Randall Leeds commented on COUCHDB-798:
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+1 on both accounts
I'm a little nervous about turning this on by default anywhere. While I wish we
could just be optimistic it's important for us to be conservative especially
when we don't have comprehensive testing across a grid of OS/Erlang
combinations, HiPE/regular, etc. But *I'd* like to turn it on in selective
places for my own builds.
On the other hand, making it default for mochijson in the absence of any flags
seems like a reasonable thing to do on trunk, maybe just after the next release
so it can bake a while. I think Adam's reasoning is sound about it being a
pretty innocuous, but important, part of the code to have running with native
speedups.
> Compile mochijson2 down to native code
> --------------------------------------
>
> Key: COUCHDB-798
> URL: https://issues.apache.org/jira/browse/COUCHDB-798
> Project: CouchDB
> Issue Type: Improvement
> Components: Database Core
> Reporter: Adam Kocoloski
> Fix For: 1.2
>
>
> Adding a -compile(native) flag to mochijson2.erl results in a marked
> performance improvement for large documents. I did the following test
> node compare_write.js -u http://127.0.0.1:5984 -v http://127.0.0.1:5985 -1
> trunk -2 mochijson2-native -d large -r 2 -t 90 -c 200
> and got the results at [1]. The graph shows that the average client response
> time dropped by about 35% with the native encoder. Qualitatively, I also
> noticed that the native encoder used substantially fewer CPU cycles. On my
> dual core Macbook, idle CPU went from ~10% on trunk to ~25% with the +native
> version while the test was running.
> Running the same test with small documents showed essentially no difference
> between the two comparatives, which is not surprising.
> A potential downside of +native is instability in the VM. I've encountered
> issues on AMD machines with R13B04 when using +native for all modules, and
> the core dump pointed to an issue in HiPE. On the other hand, I think that
> mochijson2 should work very well as native code, since it doesn't do any
> message passing or I/O. I'm +1 on simply adding the compile option to the
> codebase in trunk to see how it behaves.
> [1]:
> http://mikeal.couchone.com/graphs/_design/app/_show/compareWriteTest/e69057a29bd6e4ac4ae0115fac00ae50
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