Fixing Threads in Ruby 1.8: A 2-10x performance boost

http://timetobleed.com/fixing-threads-in-ruby-18-a-2-10x-performance-boost/

by sprsquish • 17 years ago

51 14 17 years ago

timetobleed.com

grandalf2• 17 years ago

wow this is a superb post. I wonder why anyone would really want to take the trouble to move to ruby 1.9 anymore...

I'd be curious to see the rest of the benchmarks.

jcapote• 17 years ago

I'm curious why someone would go through the trouble to stay on 1.8?

FooBarWidget2• 17 years ago

Library compatibility. Many libraries are still not compatible with 1.9. It's good to have interim improvements for 1.8 until the ecosystem has caught up with 1.9, because 1.8 is what actually powers production systems today.

wheels• 17 years ago

Note that this is pretty much only measuring thread overhead rather than thread workload throughput. So on an SMP system you'd still have the same problems with blocking I/O and only using one CPU that are part and parcel with green threads. In practice that means for something like a map-reduce pattern on a multi-core system, Ruby 1.9's native threads would win by a significant margin.

Edit: Remembered based on ice799's comment below that in 1.9 the threads still won't be allowed to operate in parallel, which neuters most of the aforementioned benefits to using native threads.

derefr2• 17 years ago

I've seen quite a few of these "improvement" posts lately, which take a feature of 1.8 and bring it into parity with the performance of 1.9. I always have the feeling that the author is just looking at what 1.9 is already doing and explaining it as if they discovered it themselves.

FooBarWidget2• 17 years ago

Your response sounds dangerously close to what pro-software patents advocates would say. Just because someone else has written software which does the same thing doesn't mean that you couldn't have discovered the same method independently.

In case of this patch, even the author himself says that Ruby 1.9 doesn't do stack copying. He's not "explaining as if he discovered it himself".

scott_s2• 17 years ago

Does anyone know what Ruby 1.9 does for creating threads? Does it do something similar to what the author does, or something else entirely?

ice7992• 17 years ago

Hi. Author here.

Ruby 1.9 uses libpthread which creates stacks for its threads in a similar way (mmap and a guard page).

scott_s2• 17 years ago

You mean it calls pthread_create for every Ruby thread? That would mean threads are no longer green threads, since both of the widely used Pthread libraries on Linux (Linuxthreads on 2.4 versions of the kernel, and NTPL on 2.6) have a 1-to-1 mapping of POSIX threads to kernel threads.

Fixing Threads in Ruby 1.8: A 2-10x performance boost

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