Pls review 6887571

[Paul Hohensee]

All suggestions taken.  The obsolete flags are DefaultMaxRAM and 
DefaultInitialRAMFraction.
DefaultMaxRAMFraction will go away later.

Paul

Jon Masamitsu wrote:
> Comment should probably say "initial heap size" instead of "minimum
> heap size".
>
> 1357     if (!FLAG_IS_DEFAULT(InitialHeapSize)) {
> 1358       // A minimum heap size was specified on the command line,
>
>
> Instead of this,
>
> 2719   // Set heap size based on available physical memory.
> 2720   // CMS uses its own heap size ergo.
> 2721   if (!UseConcMarkSweepGC) {
> 2722     set_heap_size();
> 2723   }
> 2724
> 2725   if (UseParallelGC || UseParallelOldGC) {
> 2726     // Set some flags for ParallelGC if needed.
> 2727     set_parallel_gc_flags();
> 2728   } else if (UseConcMarkSweepGC) {
> 2729     // Set some flags for CMS
> 2730     set_cms_and_parnew_gc_flags();
> 2731   } else if (UseParNewGC) {
> 2732     // Set some flags for ParNew
> 2733     set_parnew_gc_flags();
> 2734   } else if (UseG1GC) {
> 2735     // Set some flags for garbage-first, if needed.
> 2736     set_g1_gc_flags();
> 2737   }
>
> consider
>
> if (UseConcMarkSweepGC) {
>   // Set some flags for cms and ParNew.  If both
>   // UseConcMarkSweepGC and UseParNewGC are set,
>   // this is the call that should be done.
>   set_cms_and_parnew_gc_flags();
> } else {
>   set_heap_size();
>   if (UseParallelGC || UseParallelOldGC) {
>     // Set some flags for ParallelGC if needed.
>     set_parallel_gc_flags();
>   } else if (UseParNewGC) {
>     // Set some flags for ParNew
>     set_parnew_gc_flags();
>   } else if (UseG1GC) {
>     // Set some flags for garbage-first, if needed.
>     set_g1_gc_flags();
>   }
> }
>
>
> I'd suggest adding the newly obsoleted flags (e.g., DefaultMaxRAM)
> to the obsolete_jvm_flags[] in arguments.cpp.  For example
>
>   { "DefaultMaxRAM)", JDK_Version::jdk_update(6,16), 
> JDK_Version::jdk(8) }
>
>
> That's all.
>
>
> On 10/27/09 16:01, Paul Hohensee wrote:
>> .02 has the fix for line 1105.
>>
>> I'll change MaxErgoHeapSize to ErgoHeapSizeLimit, unless someone
>> else has another opinion.  I'm not proud. :)
>>
>> Thanks for the review, and for reviewing interim versions.
>>
>> Paul
>>
>> Jon Masamitsu wrote:
>>> Paul,
>>>
>>> Just a couple of comments from the .01 version
>>> of the webrev.  I haven't started the .02 version
>>> yet so may have more comments after I do.
>>>
>>> Jon
>>>
>>> arguments.cpp
>>>
>>> 1105       InitialHeapSize = min_new + OldSize;
>>>
>>> Use FLAG_SET_ERGO()
>>>
>>> FLAG_SET_ERGO(uintx, InitialHeapSize, min_new + OldSize);
>>>
>>> Sometimes in the setting of the GC policies we like to
>>> know how the flag was set.
>>>
>>> I like ErgoHeapSizeLimit instead of
>>> MaxErgoHeapSize but just my preference.
>>>
>>>
>>>
>>> On 10/27/09 09:26, Paul Hohensee wrote:
>>>> 6887571: Increase default heap config sizes
>>>>
>>>> Webrev here
>>>>
>>>> http://cr.openjdk.java.net/~phh/6887571/webrev.01/
>>>>
>>>> Some background:
>>>>
>>>> The default client vm heap config since 2000 for sparc32 has been 
>>>> the equivalent of
>>>>
>>>> -Xmx64m -XX:OldSize=4m -XX:NewSize=2m -XX:NewRatio=8
>>>> -XX:SurvivorRatio=8 -XX:MaxTenuringThreshold=15
>>>>
>>>> and for 32-bit x86
>>>>
>>>> -Xmx64m -XX:OldSize=4m -XX:NewSize=1m -XX:NewRatio=12
>>>> -XX:SurvivorRatio=8 -XX:MaxTenuringThreshold=15
>>>>
>>>> OldSize and NewSize are the initial committed sizes of the old and 
>>>> young generations
>>>> respectively.  A minor gc is required to increase the committed 
>>>> size of the young gen,
>>>> while a full gc is required to increase the committed size of the 
>>>> old gen.
>>>>
>>>> At the time, 64m was half of the 128m of memory typically available 
>>>> on high-end
>>>> desktops, many client applications were satisfied with small heaps 
>>>> (hence the
>>>> low -Xms value), and gc times were such that the young gen had to 
>>>> be small
>>>> in order to minimize pause times.
>>>>
>>>> Since that time, low end desktops and laptops, as well as netbooks 
>>>> and smartbooks,
>>>> typically come with 256m, client applications have become much more 
>>>> "server-like",
>>>> and we've realized that a small young gen size increases the 
>>>> frequency of young gcs
>>>> and the amount of transient data promoted to the old gen to levels 
>>>> that noticeably
>>>> impact startup and steady-state performance, principally by 
>>>> provoking full gcs.
>>>>
>>>> This change extends server class heap sizing to the client with a 
>>>> few changes.
>>>> Server heap sizing ergonomics should be unaffected.
>>>>
>>>> 1. NewRatio is set to 2 for all platforms to accomodate an increase 
>>>> in transient data size.
>>>>
>>>> 2. SurvivorRatio is set to 8 for all platforms.  It was 8 for every 
>>>> platform except
>>>> 64-bit x86 (where it was 6) in any case, so it isn't a big change.
>>>>
>>>> 3. MaxTenuringThreshold is left at 15 (the maximum).
>>>>
>>>> 4. I added MaxRAM, whose implemented definition matches the current 
>>>> comment for DefaultMaxRAM
>>>> in globals.hpp.  MaxRAM is the maximum physical memory size used to 
>>>> compute MaxHeapSize
>>>> rather than the maximum possible value of MaxHeapSize set by 
>>>> ergonomics.  I replaced
>>>> DefaultMaxRAM with MaxErgoHeapSize for the latter purpose.  I added 
>>>> support for a new
>>>> argument type, uint64_t, and used it as the type of MaxRAM.  uintx 
>>>> doesn't have the necessary
>>>> range on 32-bit systems: a user might want to specify 4g for MaxRAM 
>>>> on a 32-bit system.
>>>>
>>>> 5. The other Default* switches have been stripped of the "Default" 
>>>> prefix, since to me their
>>>> values are just as much "default" values as the values of any of 
>>>> other vm switch, and those don't
>>>> have a "Default" prefix.  I left DefaultMaxRAMFraction as a synonym 
>>>> for MaxRAMFraction for
>>>> the moment because QA uses it.  When they change to MaxRAMFraction, 
>>>> I intend to remove
>>>> DefaultMaxRAMFraction.
>>>>
>>>> 6. In arguments.cpp, set_heap_size() replaces 
>>>> set_server_heap_size() and is used for everything
>>>> except CMS.  CMS has it's own, incompatible (I know: I tried it), 
>>>> heap sizing ergonomics.
>>>>
>>>> 7. The minimum committed size of the old gen (OldSize) remains at 
>>>> 4m and the minimum
>>>> committed size of the young gen (NewSize) increases to 4m.  Note 
>>>> that these are the minimum,
>>>> not initial sizes.  NewSize is made common to all platforms.
>>>>
>>>> 8. I added a switch InitialHeapSize that can be used to set the 
>>>> initial committed size of the heap.
>>>> Absent specification by InitialHeapSize, the initial committed size 
>>>> is 1/64th of physical memory
>>>> or OldSize + NewSize, whichever is larger.
>>>>
>>>> 9. I cleaned up some formatting, esp. in globals.hpp.
>>>>
>>>> 10. The default MaxHeapSize is raised from 64m to 96m.  For systems 
>>>> with <= MaxHeapSize
>>>> physical memory, the minimum heap size is 1/MinRAMFraction of 
>>>> physical memory.  The
>>>> default value of MinRAMFraction is 2.  Thus, a 256m box gets a 96m 
>>>> heap, as does a 128m
>>>> box, but a 96m box gets a 48m heap and a 64m box gets a 32m heap.  
>>>> The default values of
>>>> MaxRAM and MaxRAMFraction bound the maximum heap size to 256m for 
>>>> the client vms,
>>>> 1g for 32-bit server vms and 32g for 64-bit server vms.  The values 
>>>> for the server vms are
>>>> the same as before.  I picked 256m for client because I wanted to 
>>>> bound resource utilization
>>>> on client systems.  Also, benchmarks runs showed no extra benefit 
>>>> from going to 512m heaps.
>>>> 512m is the safe maximum for the serial collector.
>>>>
>>>> Thanks,
>>>>
>>>> Paul
>>>>
>>>>
>>>>
>>>>
>>>>