Re: [rvm-research] About invocation_count_threshold

Thanks, Erik. Very nice answer!
So it seems there are two ways to determine whether a method is hot or not:
one is sampling-based, the other is (invocation) counter-based.
The former prefers methods with longer accumulated execution time, while
the later prefers methods with more invocations so far, right?


May I have a further question?

I tested the command line arguments you suggested: "-X:aos:printOptions",
from which I found two interesting options as below:

method_sample_size             = 3
counter_based_sample_interval  = 1000


It seems the first one is the threshold (# of samples a method got) to
determine a method is "hot" or not,
and the second one is the sampling rate (in the default setting, it is
taking 1 sample every 1000 msecs).

Is my understanding correct?

I observed the changing of method_sample_size affects the # of methods
opt-compiled.
However, I did not see counter_based_sample_interval affect the  # of
methods opt-compiled at all.
Did I miss anything?


Thanks again!

Zhijia













On Thu, Nov 7, 2013 at 4:13 AM, Erik Brangs <[email protected]> wrote:

> Hi,
>
> On 07.11.2013 00:04, Zhijia Zhao wrote:
> > I tried to test the effects of "invocation_count_threshold" with the
> following command.
> >
> > rvm -X:vm:measureCompilation=true -X:aos:invocation_count_threshold=1
> -jar dacapo-2006-10-MR2.jar -s small eclipse
>
> Invocation counters are disabled by default. You will need to enable them
> first by adding "-X:base:invocation_counters=true" as a command line
> argument. You will need to fix bugs if you want to use invocation counters
> (see http://jira.codehaus.org/browse/RVM-919).
>
> To see the default values of command line arguments for AOS or the
> baseline compiler, use "rvm -X:aos:printOptions" and "rvm
> -X:base:printOptions" respectively.
>
>
> Kind regards,
>
> Erik Brangs
>
>
> ------------------------------------------------------------------------------
> November Webinars for C, C++, Fortran Developers
> Accelerate application performance with scalable programming models.
> Explore
> techniques for threading, error checking, porting, and tuning. Get the most
> from the latest Intel processors and coprocessors. See abstracts and
> register
> http://pubads.g.doubleclick.net/gampad/clk?id=60136231&iu=/4140/ostg.clktrk
> _______________________________________________
> Jikesrvm-researchers mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/jikesrvm-researchers
>



-- 
Zhijia Zhao
PhD Student
Computer Science Dept., The College of William & Mary, USA
web: http://www.cs.wm.edu/caps/zzhao

------------------------------------------------------------------------------
November Webinars for C, C++, Fortran Developers
Accelerate application performance with scalable programming models. Explore
techniques for threading, error checking, porting, and tuning. Get the most 
from the latest Intel processors and coprocessors. See abstracts and register
http://pubads.g.doubleclick.net/gampad/clk?id=60136231&iu=/4140/ostg.clktrk

_______________________________________________
Jikesrvm-researchers mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/jikesrvm-researchers