[ruby-core:85979] [Ruby trunk Feature#14489] MJIT needs a reusable cache

[takashikkbn@gmail.com]

Issue #14489 has been updated by k0kubun (Takashi Kokubun).


Yeah, having capability to shut down MJIT worker earlier looks important, especially when it becomes matured and we consider enabling it by default.

It's interesting to know your new project of multi-tier JIT. If inlining takes longer compilation time or consumes larger memory, it would make a lot of sense.

Also I'm very excited to know I'll have opportunity to have a talk with you again. I'll go to RubyKaigi 2018 for sure. Let's discuss about them.

----------------------------------------
Feature #14489: MJIT needs a reusable cache
https://bugs.ruby-lang.org/issues/14489#change-70846

* Author: sam.saffron (Sam Saffron)
* Status: Rejected
* Priority: Normal
* Assignee: k0kubun (Takashi Kokubun)
* Target version: 
----------------------------------------
Currently on Discourse boot I notice a few minutes of jitting every time you boot it:

This is a redacted output: https://gist.github.com/SamSaffron/4e18c2dacf476f1f27275f5b5d7bbb97 

CPU is spinning hard compiling temp file after temp file for **minutes**:

> JIT success (213.1ms): platform_string@/home/sam/.rbenv/versions/master/lib/ruby/gems/2.6.0/gems/bundler-1.16.1/lib/bundler/lazy_specification.rb:18 -> /tmp/_ruby_mjit_p6914u199.c

and so on.

Instead, mjit should have a reusable cache on disk it first tries fetching from prior to re-compiling. It can use an ISEQ SHA1 hash as the key to the cache. 






---Files--------------------------------
14489.patch (29.8 KB)


-- 
https://bugs.ruby-lang.org/