Code review request: 7199092 NMT: NMT needs to deal overlapped virtual memory ranges

[David Holmes]

Hi Zhengyu,

I can't review the details of this (sorry) but one minor comment:

thread.cpp

1518   // Info NMT that this JavaThread is exiting, its memory
1519   // recorder should be collected
1520   assert(!is_safepoint_visible(), "wrong state");
1521   assert(get_recorder() == NULL, "Already collected");

The comment is no longer appropriate now that you aren't calling 
thread_exiting here.

David
-----

On 19/10/2012 4:54 AM, Zhengyu Gu wrote:
> The new webrev reflects some suggestions from previous code review,
> along with:
>
> 1. Caught more cases that virtual memory operations do not go through os
> api, which cause mis-matched records that confuse NMT.
> 2. Fixed a bug that JavaThread releases its per-thread recorder too
> later, so that the record could be misplaced in wrong generation.
> 3. Cleanup. Removed some dead code and unnecessary assertions
> 4. Fixed racing conditions that could mis-count arena sizes. When
> ResourceMark or HandleMark resets, it should reset arena size first,
> before release memory chunks.
> 5. Fixed missing call to record native stack on AttachListener thread.
> 6. Removed unused Arena constructor.
>
> Webrev: http://cr.openjdk.java.net/~zgu/7199092/webrev.01/
>
> Thanks,
>
> -Zhengyu
>
>
> On 9/28/2012 4:36 PM, Zhengyu Gu wrote:
>> With PermGen removal integration, virtual memory usage patterns have
>> changed vs. earlier. NMT can not longer just track reserved memory
>> regions, and assume commits and uncommits are performed from the tail
>> end.
>>
>> NMT now tracks committed memory regions, alone with reserved memory
>> regions, a virtual memory map is maintained by NMT, and it is reported
>> with detail tracking data.
>>
>> The changes also include some cleanup and enhanced assertion, etc.
>>
>> CR: http://bugs.sun.com/view_bug.do?bug_id=7199092
>> Webrev: http://cr.openjdk.java.net/~zgu/7199092/webrev.00/
>>
>>
>> An example of virtual memory map:
>>
>> Virtual memory map:
>>
>> [0x8f17e000 - 0x8f364000] reserved 1944KB for Thread Stack
>> from [Thread::record_stack_base_and_size()+0x120]
>> [0x8f17e000 - 0x8f364000] committed 1944KB from
>> [Thread::record_stack_base_and_size()+0x120]
>>
>> [0x8f389000 - 0x8f680000] reserved 3036KB for Thread Stack
>> from [Thread::record_stack_base_and_size()+0x120]
>> [0x8f389000 - 0x8f680000] committed 3036KB from
>> [Thread::record_stack_base_and_size()+0x120]
>>
>> [0x8f7dd000 - 0x8f900000] reserved 1164KB for Thread Stack
>> from [Thread::record_stack_base_and_size()+0x120]
>> [0x8f7dd000 - 0x8f900000] committed 1164KB from
>> [Thread::record_stack_base_and_size()+0x120]
>>
>> [0x8fa20000 - 0x8faa1000] reserved 516KB for Thread Stack
>> from [Thread::record_stack_base_and_size()+0x120]
>> [0x8fa20000 - 0x8faa1000] committed 516KB from
>> [Thread::record_stack_base_and_size()+0x120]
>>
>> [0x8fd30000 - 0x914b8000] reserved 24096KB for GC
>> from [ReservedSpace::initialize(unsigned int, unsigned int, bool,
>> char*, unsigned int, bool)+0x555]
>> [0x8fd30000 - 0x914b8000] committed 24096KB from
>> [PSVirtualSpace::expand_by(unsigned int)+0x95]
>>
>> [0x914b8000 - 0x916bc000] reserved 2064KB for Thread Stack
>> from [Thread::record_stack_base_and_size()+0x120]
>> [0x914b8000 - 0x916bc000] committed 2064KB from
>> [Thread::record_stack_base_and_size()+0x120]
>>
>> [0x916bc000 - 0x91860000] reserved 1680KB for GC
>> from [ReservedSpace::initialize(unsigned int, unsigned int, bool,
>> char*, unsigned int, bool)+0x555]
>> [0x916bc000 - 0x916c7000] committed 44KB from
>> [PSVirtualSpace::expand_by(unsigned int)+0x95]
>> [0x91764000 - 0x9176f000] committed 44KB from
>> [CardTableModRefBS::resize_covered_region(MemRegion)+0xebf]
>> [0x9180b000 - 0x91811000] committed 24KB from
>> [CardTableModRefBS::resize_covered_region(MemRegion)+0xebf]
>> [0x9185f000 - 0x91860000] committed 4KB from
>> [CardTableModRefBS::CardTableModRefBS(MemRegion, int)+0x2a0]
>>
>> [0x91860000 - 0xb1060000] reserved 516096KB for Java Heap
>> from [ReservedSpace::initialize(unsigned int, unsigned int, bool,
>> char*, unsigned int, bool)+0x190]
>> [0x91860000 - 0x92d50000] committed 21440KB from
>> [PSVirtualSpace::expand_by(unsigned int)+0x95]
>> [0xa6710000 - 0xa7180000] committed 10688KB from
>> [PSVirtualSpace::expand_by(unsigned int)+0x95]
>> [0xb0e60000 - 0xb0ea9000] committed 292KB from
>> [VirtualSpace::initialize(ReservedSpace, unsigned int)+0x3e8]
>>
>> [0xb1069000 - 0xb71e9000] reserved 99840KB for Code
>> from [ReservedSpace::initialize(unsigned int, unsigned int, bool,
>> char*, unsigned int, bool)+0x555]
>> [0xb1069000 - 0xb1072000] committed 36KB from
>> [VirtualSpace::initialize(ReservedSpace, unsigned int)+0x3e8]
>> [0xb11e9000 - 0xb1429000] committed 2304KB from
>> [VirtualSpace::initialize(ReservedSpace, unsigned int)+0x3e8]
>>
>> [0xb71e9000 - 0xb77e9000] reserved 6144KB for Class
>> from [ReservedSpace::initialize(unsigned int, unsigned int, bool,
>> char*, unsigned int, bool)+0x555]
>> [0xb71e9000 - 0xb750a000] committed 3204KB from
>> [VirtualSpace::initialize(ReservedSpace, unsigned int)+0x3e8]
>>
>> [0xb77e9000 - 0xb783a000] reserved 324KB for Thread Stack
>> from [Thread::record_stack_base_and_size()+0x120]
>> [0xb77e9000 - 0xb783a000] committed 324KB from
>> [Thread::record_stack_base_and_size()+0x120]
>>
>> Tests performed:
>> - JPRT tests
>>
>> - Linux 32 bit:
>> vm.quick.testlist
>> nsk.stress
>> runtime.ParallelClassLoading
>> nsk.quick-jdi.testlist
>> nsk.quick-jvmti.testlist
>>
>> - Solaris x64
>> vm.quick.testlist
>> runtime.ParallelClassLoading
>> nsk.stress.jck60
>>
>> - Solaris sparcv9
>> vm.quick.testlist
>> runtime.ParallelClassLoading
>> nsk.stress.jck60
>>
>>
>> Thanks,
>>
>> -Zhengyu