On 6/2/06, Charles O Nutter <
[EMAIL PROTECTED]> wrote:
FYI, the ObjectSpace performance hit appears to come from its use of a synchronized Set. If I modify it to use an unsynchronized Set, the numbers approach those when I have it completely disabled. Who says synchronization costs nothing?
The ObjectSpace thing is particularly interesting since it would have performance gains across the board, for all objects instantiated anywhere, any time.
On 6/2/06, Charles O Nutter <[EMAIL PROTECTED]> wrote:Some notes on performance exploration. Most of this is based on my belief that our core interpreter and the core native types (strings, symbols, fixnums, etc) are a large source of our performance woes. C Ruby is able to use extremely lightweight structs for most of these core types, and runs blazing fast (order of magnitude faster in many cases).
- Caching of all literal fixnums
I tested this by holding Long objects in the AST and adding a cache to the runtime. The results were not terribly promising, and only showed marginal gains.
Tested with:
t = Time.now; 1_000_000.times { 1000; 2000; 3000; 4000; }; p Time.now - t
Before cache: 5.15s avg
After cache: 4.7s avg, 8% improvement
- Caching of all literal floats
Same solution as above, but better results.
Before cache: 18.2s avg
After cache: 5.2s avg, 71% improvement
...However it seems unlikely that literal floats are a common performance problem. On the other hand, Floats are so drastically slow without caching I have to wonder if something's amiss.
- Disable ObjectSpace
I started tracing through our object creation versus Ruby's, and along the way thought I'd try disabling ObjectSpace entirely. The results were surprising.
Tested with:
t = Time.now; 1_000_000.times { '1000'; '2000'; '3000'; '4000'; }; p Time.now - t
Before disabling: 15.65s avg
After disabling: 5.76s avg, 64% improvement
Now we're getting somewhere. Our ObjectSpace appears to be a source of some severe performance issues. That needs to be addressed.
...
In general, I think there's a lot of performance to be gained from very small tweaks to the core interpreter and classes. Something as simple as removing the add of an object to ObjectSpace gives a 64% improvement in speed; minor caching tweaks can produce similar results. As a whole, each of these little fixes and tweaks will very quickly add up.
--
Charles Oliver Nutter @ headius.blogspot.com
JRuby Developer @ jruby.sourceforge.net
Application Architect @ www.ventera.com
--
Charles Oliver Nutter @ headius.blogspot.com
JRuby Developer @ jruby.sourceforge.net
Application Architect @ www.ventera.com
--
Charles Oliver Nutter @ headius.blogspot.com
JRuby Developer @ jruby.sourceforge.net
Application Architect @ www.ventera.com
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