8169001: Remove launcher's built-in ergonomics

[David Holmes]

Hi Kumar,

FYI regarding the test, I was mis-remembering - it was actually an issue 
with the VM's notion of is_server_class_machine(), not the launcher. 
It's used for GC ergonomic selection.

Cheers,
David

On 9/11/2016 3:28 AM, Kumar Srinivasan wrote:
>
> Hi David,
>
> Thanks for the review please see embedded comments:
>
>> 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 */);
>
> To clarify:
>
> -159                    const_cpwildcard, const_javaw, const_ergo_class);
> +159                    const_cpwildcard, const_javaw, 0);
>
>
> JLI_Launch is an *internal* entry point, this is primarily used in main.c,
> and this is called by JDK's tool launchers which sets
> "NEVER_ACT_AS_SERVER",
> also this entry point is used by the java packager and deployment, I
> have cc'ed
> Chris Bensen and David DeHaven, my take is not to change the signature now.
> Chris, David ?
>
>>
>> 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?
>
> This entry point is for internal users only.
>
>>
>> -     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.
>
> Ugh (and thanks!), I was too aggressive, this should remain, I will put
> it back in the next revision.
>
>>
>> ---
>>
>> 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).
>
> I had to mull on this, one hand jvm.cfg should reflect the VMs we support,
> but we could have someone build client vm. I will go with making the change
> you suggested.
>
>>
>> ---
>>
>> You have updated a number of copyright notices but not all of them.
>
> Yes, I vaguely recall, that the CR should be updated if there is any
> content
> that ought to be copyrighted, in this case several changes are typo
> fixups in the
> comments. So I don't think it is warranted.
>
>>
>> ---
>>
>> 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).
>
> I ran -testset pit, saw no failures,  I will perform a  -testset hotspot.
> Note though, several test changes had to be made, when Solaris 32-bit
> was yanked out.
>
> Thanks
> Kumar
>
>>
>> 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
>>>
>