How to change compilation policy to trigger C2 compilation ASAP?

[Tangwei (Euler)]

Hi Zoltan, 
  Is this option supported in OpenJDK8? I cannot find it by greping output of command line 'java -XX:+PrintFlagsFinal'. 


Regards!
wei

> -----Original Message-----
> From: hotspot-compiler-dev
> [mailto:hotspot-compiler-dev-bounces at openjdk.java.net] On Behalf Of Zoltán
> Majó
> Sent: Wednesday, May 20, 2015 2:47 PM
> To: hotspot-compiler-dev at openjdk.java.net
> Subject: Re: How to change compilation policy to trigger C2 compilation ASAP?
> 
> Hi Wei,
> 
> 
> On 05/20/2015 03:12 AM, Vladimir Kozlov wrote:
> [...]
> > 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
> old
> > Scaling,0.5
> >
> 
> just to complement what Vladimir suggested: If you want to scale thresholds
> for all methods at once, the CompileThresholdScaling can be also used globally.
> For example, -XX:CompileThresholdScaling=0.5 would reduce all thresholds by
> half (both with tiered and non-tiered modes of operation).
> 
> Best regards,
> 
> 
> Zoltan
> 
> >
> > 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
> >>