How to change compilation policy to trigger C2 compilation ASAP?

[Tangwei (Euler)]

Vladimir,
  What the 'double' means in following command line? The option CompileThresholdScaling you mentioned is same as ProfileMaturityPercentage? 
I cannot find the option in code. How much effect to function inlining by turning off tiered compilation? 

> -XX:CompileCommand=option,SomeClass.someMethod,double,CompileThresholdScaling,0.5

Regards!
wei

> -----Original Message-----
> From: Vladimir Kozlov [mailto:vladimir.kozlov at oracle.com]
> Sent: Wednesday, May 20, 2015 9:12 AM
> To: Tangwei (Euler); Vitaly Davidovich
> Cc: hotspot compiler
> Subject: Re: How to change compilation policy to trigger C2 compilation ASAP?
> 
> If you want only C2 compilation you can disable tiered compilation (since you
> don't want to spend to much on profiling anyway) and set low
> CompileThreshold (you need only this one for non-tiered compile):
> 
> -XX:-TieredCompilation -XX:CompileThreshold=100
> 
> If your method is simple and don't need profiling or inlining the generated code
> could be same quality as with long profiling.
> 
> An other approach is to set threshold per method (scale all threasholds (C1, C2,
> interpreter) by this value). For example to reduce thresholds by half:
> 
> -XX:CompileCommand=option,SomeClass.someMethod,double,CompileThresh
> oldScaling,0.5
> 
> Vladimir
> 
> On 5/19/15 5:43 PM, Tangwei (Euler) wrote:
> > My goal is just to reach peak performance quickly. Following is one
> > tier threshold combination I tried:
> >
> > -XX:Tier0ProfilingStartPercentage=0
> >
> > -XX:Tier3InvocationThreshold=3
> >
> > -XX:Tier3MinInvocationThreshold=2
> >
> > -XX:Tier3CompileThreshold=2
> >
> > -XX:Tier4InvocationThreshold=4
> >
> > -XX:Tier4MinInvocationThreshold=3
> >
> > -XX:Tier4CompileThreshold=2
> >
> > Regards!
> >
> > wei
> >
> > *From:*Vitaly Davidovich [mailto:vitalyd at gmail.com]
> > *Sent:* Tuesday, May 19, 2015 9:33 PM
> > *To:* Tangwei (Euler)
> > *Cc:* hotspot compiler
> > *Subject:* Re: How to change compilation policy to trigger C2
> > compilation ASAP?
> >
> > Is your goal specifically to have C2 compile or just to reach peak
> > performance quickly? It sounds like the latter.  What values did you
> > specify for the tier thresholds? Also, it may help you to
> > -XX:+PrintCompilation to tune the flags as this will show you which
> > methods are being compiled, when, and at what tier.
> >
> > sent from my phone
> >
> > On May 19, 2015 9:01 AM, "Tangwei (Euler)" <tangwei6 at huawei.com
> > <mailto:tangwei6 at huawei.com>> wrote:
> >
> > Hi All,
> >
> >    I want to run a JAVA application on a performance simulator, and do
> > a profiling on a hot function JITTed with C2 compiler.
> >
> > In order to make C2 compiler compile hot function as early as
> > possible, I hope to reduce the threshold of function invocation
> >
> > count in interpreter and C1 to drive the JIT compiler transitioned to
> > Level 4 (C2) ASAP. Following is the option list I try, but
> >
> > failed to find a right combination to meet my requirement. Anyone can
> > help to figure out what options I can use?
> >
> > Thanks in advance.
> >
> > -XX:Tier0ProfilingStartPercentage=0
> >
> > -XX:Tier3InvocationThreshold
> >
> > -XX:Tier3MinInvocationThreshold
> >
> > -XX:Tier3CompileThreshold
> >
> > -XX:Tier4InvocationThreshold
> >
> > -XX:CompileThreshold
> >
> > -XX:Tier4MinInvocationThreshold
> >
> > -XX:Tier4CompileThreshold
> >
> > Regards!
> >
> > wei
> >