How to change compilation policy to trigger C2 compilation ASAP?

[Tangwei (Euler)]

Thanks, we haven't switched to JDK9, and will give a try. 


Regards!
wei

> -----Original Message-----
> From: Zoltán Majó [mailto:zoltan.majo at oracle.com]
> Sent: Wednesday, May 20, 2015 4:11 PM
> To: Tangwei (Euler); 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 10:07 AM, Tangwei (Euler) wrote:
> > Hi Zoltan,
> >    Is this option supported in OpenJDK8? I cannot find it by greping output
> of command line 'java -XX:+PrintFlagsFinal'.
> 
> I checked and it is available only in 9.
> 
> Best regards,
> 
> 
> Zoltan
> 
> >
> >
> > 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
> >>>>