8169001: Remove launcher's built-in ergonomics

[David Holmes]

Hi Kumar,

On 8/11/2016 4:47 AM, Kumar Srinivasan wrote:
>
> Hello,
>
> Please review the fix for:
> https://bugs.openjdk.java.net/browse/JDK-8169001
>
> Webrev at:
> http://cr.openjdk.java.net/~ksrini/8169001/webrev.00/

Overall this looks like a complete eradication of the launcher 
ergonomics. A few specific comments:

src/java.base/share/native/launcher/main.c

!                    const_cpwildcard, const_javaw, 0);

Can you clarify this change with

!                    const_cpwildcard, const_javaw, 0 /* unused */);

Thanks.

---

src/java.base/share/native/libjli/java.c

  220         jint ergo                               /* unused */

I assume JLI_Launch is an exported API otherwise I'd expect this to be 
deleted. The fact it is unused should also be documented in 
src/java.base/share/native/libjli/java.h. But I'm also wondering where 
this API change is being documented for external users?

-     FreeKnownVMs();  /* after last possible PrintUsage() */

Not clear why you no longer need to free here. But if you don't then 
FreeKnownVMs() seems to be dead code now.

---

src/java.base/unix/conf/i586/jvm.cfg

I think you still need an entry for "-client KNOWN" as anyone can build 
the client VM if they choose. Ditto for 
src/java.base/unix/conf/sparc/jvm.cfg (though 32-bit Solaris builds are 
obsolete now).

---

You have updated a number of copyright notices but not all of them.

---

I see no changes to tests, but I'm pretty sure we have a test for 
server-class-machine somewhere (or we did - I recall it breaking at some 
point).

Thanks,
David

> Background:
>> Launcher ergonomics was introduced last decade to help determine
>> if the execution system is "Server Class", this was necessary to
>> choose server VM on platforms that supported both client and server
>> VMs (primarily for Solaris and Linux 32-bit).
>>
>> The algorithm involves computing and detecting the number of CPUs
>> and the amount of memory on the target system. All modern computers
>> systems with hyper-threading cause the ergonomics to choose server.
>>
>> JDK9 Platforms that have only server vm.
>>
>> ./linux-x64/lib/amd64/server/libjvm.so
>> ./linux-arm64-vfp-hflt/lib/aarch64/server/libjvm.so
>> ./solaris-sparcv9/lib/sparcv9/server/libjvm.so
>> ./solaris-x64/lib/amd64/server/libjvm.so
>> ./windows-x86/bin/server/jvm.dll
>> ./windows-x64/bin/server/jvm.dll
>>
>> JDK9 Platforms that have more than one vm variant:
>> ./linux-arm32-vfp-hflt/lib/arm/client/libjvm.so (default)
>> ./linux-arm32-vfp-hflt/lib/arm/minimal/libjvm.so
>>
>> ./linux-x86/lib/i386/server/libjvm.so (default)
>> ./linux-x86/lib/i386/minimal/libjvm.so
>>
>>
>> In the cases where multiple VMs are supported the ergnomics
>> has no effect, and the default platforms are chosen by the
>> jvm.cfg. Thus the launcher ergonomics is obsolete and redundant.
>
> Thanks
> Kumar
>