RFR: 8166002: Emulate client build on platforms with reduced virtual address space

Jamsheed C m jamsheed.c.m at oracle.com
Tue Jan 3 16:17:26 UTC 2017 

Hi Vladimir,

On 1/3/2017 11:15 AM, Vladimir Kozlov wrote:
> Hi Jamsheed
>
> Why you moved set_client_compilation_mode() to c1_globals and new 
> class? Why not to keep it in compilerDefinitions?
>
Done.
> selected_with_other_flags setting and code in 
> compilation_mode_selected() have the same checks - factor them into 
> one function.
Done.
>
> I would suggest to keep comment in compilationPolicy.cpp.
Done.
revised webrev: http://cr.openjdk.java.net/~jcm/8166002/webrev.05/

Best Regards,
Jamsheed
>
> I reviewed CCC request.
>
> Thanks,
> Vladimir
>
> On 1/2/17 8:25 PM, Jamsheed C m wrote:
>> Hi Vladimir, Igor,
>>
>> i changed implementation a little bit(i.e now more close to -client 
>> behavior). Tests are modified to support this mode.
>>
>> http://cr.openjdk.java.net/~jcm/8166002/webrev.04/
>>
>>
>> A new command-line option -XX:CompilationMode=<server/client> will be 
>> provided in JDK 9 to emulate a client build on
>> 32-bit Windows platforms using a standard tiered build.
>>
>> -XX:CompilationMode=server--selects to build time compilation mode of 
>> server VM.
>> -XX:CompilationMode=client--selects non-tiered c1 compiler. (Serial 
>> Garbage Collection in ON and Xshare is set to auto
>> in this mode).
>>
>> This option is available only on Tiered build (i.e. Server VM).
>> Client VM ignores this flag and continues with build time compilation 
>> mode.
>>
>> This option will have no effect if any of TieredCompilation, 
>> TieredStopAtLevel, UseAOT, EnableJVMCI, UseJVMCICompiler is
>> specified at the command-line.
>>
>> Platforms except 32-bit Windows runs in server compilation mode by 
>> default. 32-bit Windows runs in client compilation
>> mode by default. The user should specify 
>> -XX:CompilationMode=<server/client> to switch.
>>
>> -XX:+/-TieredCompilation or -XX:TieredStopAtLevel=<0-4> or 
>> -XX:+/-UseAOT or -XX:+/-EnableJVMCI or
>> -XX:+/-UseJVMCICompiler always switch to build time compilation mode 
>> plus corresponding option behavior irrespective of
>> CompilationMode option.
>>
>> I have updated the CCC request link in bug report, Please review.
>>
>> Best Regards,
>> Jamsheed
>>
>> On 12/6/2016 12:22 AM, Vladimir Kozlov wrote:
>>> On 12/5/16 6:21 AM, Jamsheed C m wrote:
>>>> Hi Vladimir,
>>>>
>>>> On 12/3/2016 8:02 AM, Vladimir Kozlov wrote:
>>>>> On 12/2/16 7:38 AM, Jamsheed C m wrote:
>>>>>> Hi Vladimir, Igor,
>>>>>>
>>>>>> I made a few more changes to include the optimization that was 
>>>>>> available only on client.
>>>>>>
>>>>>> 1) a few c1 changes (JDK-7153771..)
>>>>>
>>>>> Which one?
>>>> This one.
>>>
>>> I see.
>>>
>>> Thanks,
>>> Vladimir
>>>
>>>> src/share/vm/c1/c1_Compilation.hpp
>>>>
>>>>   // will compilation make optimistic assumptions that might lead to
>>>>     // deoptimization and that the runtime will account for?
>>>>     bool is_optimistic() const                             {
>>>> - return !TieredCompilation &&
>>>> + return is_client_compilation_mode_vm() &&
>>>>         (RangeCheckElimination || UseLoopInvariantCodeMotion) &&
>>>> method()->method_data()->trap_count(Deoptimization::Reason_none) == 0;
>>>>     }
>>>>
>>>> src/share/vm/c1/c1_Runtime1.cpp
>>>> - assert(!TieredCompilation, "incompatible with tiered compilation");
>>>> + assert(is_client_compilation_mode_vm(), "incompatible in non 
>>>> client modes");
>>>>
>>>> mpegaudio was about 6% low without this.
>>>>
>>>>>>
>>>>>> 2) Made SerialGC as default GC.
>>>>>
>>>>> Should be only for client_compilation_mode
>>>> Ok.
>>>>>
>>>>>>
>>>>>> 3) Set CICompileCount=1 for client compilation mode.
>>>>>
>>>>> I think check should be is_client_compilation_mode_vm()
>>>> Ok.
>>>> Best Regards,
>>>> Jamsheed
>>>>>
>>>>>>
>>>>>> 4) Tuned thresholds to get better performance.
>>>>>
>>>>> ok
>>>>>
>>>>>>
>>>>>> 5) Added relevant flags in few tests, modified 
>>>>>> TestSelectDefaultGC.java.
>>>>>
>>>>> ok
>>>>>
>>>>> Thanks,
>>>>> Vladimir
>>>>>
>>>>>>
>>>>>> revised webrev: http://cr.openjdk.java.net/~jcm/8166002/webrev.03/
>>>>>>
>>>>>> performance report is added in bug report.
>>>>>>
>>>>>> Best Regards,
>>>>>>
>>>>>> Jamsheed
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 11/1/2016 1:14 AM, Vladimir Kozlov wrote:
>>>>>>> webrev.02 looks good to me too.
>>>>>>>
>>>>>>> Thanks,
>>>>>>> Vladimri
>>>>>>>
>>>>>>> On 10/31/16 10:39 AM, Igor Veresov wrote:
>>>>>>>> Jamsheed explained to me that ReservedCodeCacheSize is now set 
>>>>>>>> in the else clause (udiffs are not showing the
>>>>>>>> proper alignment and I missed it). The change looks good to me.
>>>>>>>>
>>>>>>>> igor
>>>>>>>>
>>>>>>>>> On Oct 31, 2016, at 9:42 AM, Igor Veresov 
>>>>>>>>> <igor.veresov at oracle.com> wrote:
>>>>>>>>>
>>>>>>>>> Assuming it gets the performance/startup numbers close to the 
>>>>>>>>> client VM it looks fine.
>>>>>>>>> But what about adjusting the code cache sizes? With tiered we 
>>>>>>>>> get 240M ReservedCodeCacheSize, which also turns
>>>>>>>>> on SegmentedCodeCache. It seems like we won’t need the 
>>>>>>>>> “profiled” segment of the code
>>>>>>>>> cache at all. It is also likely that we’d do fine with a 
>>>>>>>>> smaller overall code cache.
>>>>>>>>>
>>>>>>>>> igor
>>>>>>>>>
>>>>>>>>>> On Oct 31, 2016, at 9:14 AM, Jamsheed C m 
>>>>>>>>>> <jamsheed.c.m at oracle.com> wrote:
>>>>>>>>>>
>>>>>>>>>> Hi Vladimir, Igor,
>>>>>>>>>>
>>>>>>>>>> revised webrev: 
>>>>>>>>>> http://cr.openjdk.java.net/~jcm/8166002/webrev.02/
>>>>>>>>>>
>>>>>>>>>> i took flags from bug comment.
>>>>>>>>>>
>>>>>>>>>> Igor V. suggested next flags setting to emulate Client VM 
>>>>>>>>>> compile threshold with TieredStopAtLevel=1:
>>>>>>>>>>
>>>>>>>>>> Tier3BackEdgeThreshold=14000
>>>>>>>>>> Tier3CompileThreshold=1500
>>>>>>>>>> Tier3InvocationThreshold=1500
>>>>>>>>>> Tier3MinInvocationThreshold =1500
>>>>>>>>>>
>>>>>>>>>> Best Regards,
>>>>>>>>>>
>>>>>>>>>> Jamsheed
>>>>>>>>>>
>>>>>>>>>> On 10/28/2016 11:48 PM, Vladimir Kozlov wrote:
>>>>>>>>>>> Add comment what the code does and why. Move the code into 
>>>>>>>>>>> separate function reaturning bool. And condition
>>>>>>>>>>> CodeCache setting based on result. It will reduce #ifdef mess.
>>>>>>>>>>>
>>>>>>>>>>> Can you put && to the end of previous line? To get good 
>>>>>>>>>>> alignment.
>>>>>>>>>>> Should we also change CompilationPolicyChoice?
>>>>>>>>>>>
>>>>>>>>>>> Ask Igor Veresov to verify settings.
>>>>>>>>>>>
>>>>>>>>>>> Thanks,
>>>>>>>>>>> Vladimir
>>>>>>>>>>>
>>>>>>>>>>> On 10/28/16 10:59 AM, Jamsheed C m wrote:
>>>>>>>>>>>> Hi Vladimir,
>>>>>>>>>>>>
>>>>>>>>>>>> revised webrev with just ergo settings for win32.
>>>>>>>>>>>>
>>>>>>>>>>>> http://cr.openjdk.java.net/~jcm/8166002/webrev.01/
>>>>>>>>>>>>
>>>>>>>>>>>> Best Regards
>>>>>>>>>>>>
>>>>>>>>>>>> Jamsheed
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> On 10/28/2016 12:25 PM, Vladimir Kozlov wrote:
>>>>>>>>>>>>> Hi Jamsheed,
>>>>>>>>>>>>>
>>>>>>>>>>>>> Why you need changes in tests?
>>>>>>>>>>>>>
>>>>>>>>>>>>> Why you can't use set_client_compilation_mode() in both 
>>>>>>>>>>>>> places?
>>>>>>>>>>>>>
>>>>>>>>>>>>> Looks fine otherwise.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Thanks,
>>>>>>>>>>>>> Vladimir
>>>>>>>>>>>>>
>>>>>>>>>>>>> On 10/20/16 8:45 AM, Jamsheed C m wrote:
>>>>>>>>>>>>>> Hi All,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> bug id:https://bugs.openjdk.java.net/browse/JDK-8166002
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> http://cr.openjdk.java.net/~jcm/8166002/webrev.00/
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Fix: set NeverActAsServerClassMachine=true, Limit 
>>>>>>>>>>>>>> TieredCompilation to C1 by default, for win32 platform.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> A new flag CompilationMode=<client/server> is introduced 
>>>>>>>>>>>>>> to select server/ client mode compilation. This
>>>>>>>>>>>>>> option is supported only in TIERED builds.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> -XX:CompilationMode=server supports both 
>>>>>>>>>>>>>> -XX:+/-TieredCompilation.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> -XX:CompilationMode:client ignores TieredCompilation flag.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Please review,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Best Regards,
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Jamsheed
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>
>>>>
>>

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