Benchmarks

> Hi,
>
> I think that most of you have seen the tinyBechmarks results :
> http://fbanados.wordpress.com/2011/02/10/a-tinybenchmark/
> In order to understand why we are I last, I've made some benchmarks:
>
> (***WARNING*** my vm was compiled without the generation gc to use vallgrind)
>
> 1) Simple optimized byte codes:
> ========================
>
> x timesRepeat: [ 1 + 1 ]
>
>    [1] source code line number 1
>    [3] push 100
>    [5] dup stack top
>    [7] dup stack top
>    [9] push 1
>        send 1 args message #>=
>   [11] pop and if false jump to 21
>   [13] push 1
>        send 1 args message #-
>   [15] push 1
>   [17] push 1
>        send 1 args message #+
>   [19] pop stack top
>        jump to 7
>   [21] pop stack top
>   [23] return stack top
>
> It only sends optimized byte codes and never send a message; I've choosen it
> to stress the byte code decoder and also never calls a GC.
>
> I've done it also with other optimized messages like at:, at:put:
>
> We are up to 3 times faster than cog.
>
> 2) Some optimized message send:
> ==========================
>
> SmallInteger [
>  selfReturn [
>    ^ self
>  ]
>
>  literalReturn [
>    ^ Object
>  ]
> ]
>
> x timesRepeat: [ 1 selfReturn ] or x timesRepeat: [ 1 literalReturn ]
>
> Here we stress another part of the VM _gst_message_send :
>  1) "selfReturn" call  a full lookup is done
>  2) after the cache does it work
>
> in _gst_message_send_internal the message is optimized too it
> will directly return the self or the literals,... we never create a context
> and trigger a GC too
>
> Here again we are faster than cog
>
> 3) Simple context activation:
> =====================
>
> SmallInteger [
>  foo [
>    ^ 1+1
>  ]
> ]
>
> Again we stress _gst_message_send_internal but the messsage is really sent, so
> what's the difference:
>  - a context is allocated
>  - and recycled
>  - GC is never call
>
> Here again we are faster than cog
>
> 4) Now here comes the problem:
> =======================
>
> SmallInteger [
>  foo: anInteger time: aTimeInteger [
>    anInteger > 0 ifTrue: [
>      ^ self  foo: anInteger - 1 time: aTimeInteger
>    ].
>
>    ObjectMemory quit.
>  ]
> ]
>
> Here another part of the vm is stressed :
>
> context activation (they are not recycled here) and this is the problem
> (***WARNING*** my vm was compiled without the generation gc to use vallgrind)
>
> 1) a GC is called => 76% of the global times of execution, it seems to
> be the problem
>
> 2) when gst is out of free chunk with long recursions it crashes :
> empty_context_stack
>
> 3) all the time an oop entry is allocated also gst could be low on oop
> and trigger a gc
>
> I hope those tiny simple benchmarks will help the gst community ;-)
>
> Cheers,
> Gwen
>