Updated: RFR(L) 8046598: Scalable Native memory tracking development

[Zhengyu Gu]

Hi Christian,

Thanks for the review.

On 8/6/2014 9:28 AM, Christian Tornqvist wrote:
> Hi Zhengyu,
>
> Split the assert at:
>
> src/share/vm/services/memBaseline.hpp @136
Will do.

> As mentioned during our code review meetings, "at" is not a good name for a
> method and should be renamed to be more descriptive
> (src/share/vm/services/memTracker.cpp @242)
This is a bug, should overwrite virtual function do_malloc_site(), 
forgot change this one.

-Zhengyu


> Otherwise this looks good.
>
> Thanks,
> Christian
>
> -----Original Message-----
> From: hotspot-dev [mailto:hotspot-dev-bounces at openjdk.java.net] On Behalf Of
> Zhengyu Gu
> Sent: Monday, August 4, 2014 2:23 PM
> To: hotspot-dev at openjdk.java.net
> Subject: Updated: RFR(L) 8046598: Scalable Native memory tracking
> development
>
> The update is based on code review meetings with Coleen, Christian, George
> and Harold.
>
> http://cr.openjdk.java.net/~zgu/8046598/webrev.01/
> <http://cr.openjdk.java.net/%7Ezgu/8046598/webrev.01/>
>
>
> Thanks,
>
> -Zhengyu
>
>
>
> On 7/15/2014 4:12 PM, Zhengyu Gu wrote:
>> This is an update to previous RFR 8028541: Native Memory Tracking
>> enhancement, the original one is closed as duplicate of current one.
>>
>> The update is mainly based on feedback from Coleen and Christian:
>>    - Refactored MemReporter to break up some large functions and
>> eliminate duplicated code.
>>    - Minor change to MemBaseline for eliminating duplicated code.
>>    - Changed MEMFLAGS type from unsigned  short => MemoryType.
>>
>> Also added unit tests for LinkedList.
>>
>> The note from  RFR 8028541:
>> =========================
>> This is significant rework of native memory tracking introduced in
>> earlier releases.
>>
>> The goal of this enhancement is to improve scalability, from both
>> tracking memory and CPU usage perspectives, so it can scale well with
>> increased memory allocation in large applications.
>>
>> The enhancement is mainly focused on malloc memory tracking, whose
>> activities are several magnitude higher than virtual memory, and was
>> the main bottleneck in early implementation.
>>
>> Instead of using book keeping records for tracking malloc activities,
>> new implementation co-locates tracking data along side with user data
>> by using a prefixed header. The header size is 8 bytes on 32-bit
>> systems and 16 bytes on 64-bit systems, which ensure that user data
>> also align properly.
>>
>> Virtual memory tracking still uses book keeping records, and
>> ThreadCritical lock is always acquired to alter the records and
>> related data structures.
>>
>> Summary tracking data is maintained in static data structures, via
>> atomic operations. Malloc detail tracking call stacks are maintained
>> in a lock free hashtable.
>>
>> The key improvements:
>>    1. Up-to-date tracking report.
>>    2. Detail tracking now shows multiple call frames. Number of frames
>> is compilation time decision, currently default to 4.
>>    3. Malloc tracking is lock free.
>>    4. Tracking summary is reported in hs_err file when native memory
>> tracking is enabled.
>>    5. Query is faster, uses little memory and need a very little process.
>>
>> The drawback is that, malloc tracking header is always needed if
>> native memory tracking has ever been enabled, even after tracking is
>> shutdown.
>>
>> Impacts:
>>    The most noticeable impact for JVM developers, is that Arena now
>> also take memory type as constructor parameter, besides the new
>> operators.
>>       Arena* a = new (mtCode) Arena()  => Arena* a = new (mtCode)
>> Arena(mtCode)
>>
>> The webrev shows modification of about 60 files, but most of them are
>> due to tracking API changes, mainly due to tracking stack, now, is an
>> object, vs. a single pc.
>>
>> The most important files for this implementations are:
>>
>> memTracker.hpp/cpp
>> mallocTracker.hpp/cpp and mallocTracker.inline.hpp
>> virtualMemoryTracker.hpp/cpp
>> mallocSiteTable.hpp/cpp
>>
>> allocationSite.hpp
>> nativeCallStack.hpp/cpp
>> linkedlist.hpp
>>
>>
>> Tests:
>>    - JPRT
>>    - NMT test suite
>>    - vm.quick.testlist
>>    - Kitchensink stability test for 16+ days
>>    - FMW
>>
>>
>>
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8046598
>> Webrev: http://cr.openjdk.java.net/~zgu/8046598/webrev.00/
>> <http://cr.openjdk.java.net/%7Ezgu/8046598/webrev.00/>
>>
>>
>>
>> Thanks,
>>
>> -Zhengyu
>>
>