HHVM/About/en

HHVM (also known as the HipHop Virtual Machine) is a virtual machine for PHP, with an associated just-in-time (JIT) compiler. Deploying HHVM on a MediaWiki wiki should lead to performance improvements across the board for most users.

Currently, on Wikimedia wikis, you can opt-in as an editor to using HHVM through the Beta Features tab in your preferences. You can verify that it is enabled for you by visiting Special:Version on your wiki, and checking that it says "HHVM" instead of "PHP" in the "Installed software" table. Once the developers and sysadmins are satisfied that it is stable enough, it will become the default for all users.

Our preliminary benchmarks show that HHVM is significantly faster than the current PHP interpreter.

FAQ

 * How do I know if an edit was made via HHVM?
 * All edits and log entries made via HHVM are tagged so they can be [//www.mediawiki.org/w/index.php?namespace=&tagfilter=HHVM&translations=filter&title=Special%3ARecentChanges filtered] on Special:RecentChanges. This is to enable faster discovery of any potential bugs.
 * When will the tags be removed?
 * In approximately 3 months, mid-January, if everything goes smoothly.
 * Why are edits made using gadgets not using HHVM?
 * Most gadgets use the API to edit, which currently does not support this beta feature.
 * What are the known issues with HHVM?
 * All bugs related to HHVM are tagged with the keyword "hhvm" on, so you can use a [//bugzilla.wikimedia.org/buglist.cgi?keywords=hhvm&keywords_type=allwords&list_id=345439&query_format=advanced&resolution=--- saved search] to see all open bugs.
 * Where should I report issues that I think are related to HHVM?
 * If you're familiar with bugzilla, feel free to file a bug there and tag it with the "hhvm" keyword. If you're familiar with IRC, join #wikimedia-tech and report it there. Or just leave a report on the talk page.