RFR: 8199067 [REDO] NMT: Enhance thread stack tracking

[Thomas Stüfe]

Hi Zhengyu,

Looks fine now!

Thanks Thomas

On Thu 12. Apr 2018 at 22:13, Zhengyu Gu <zgu at redhat.com> wrote:

> Hi Thomas,
>
> Thanks for the review.
>
> On 04/11/2018 10:38 AM, Thomas Stüfe wrote:
> > Hi Zhengyu,
> >
> > sorry for the late response!
> >
> > I looked the windows changes over.
> >
> > The capping of the size may not work correctly if the committed range
> > overlaps the end of the region but starts in the middle:
> >
> > +    // current region may go beyond the limit, trim to the limit
> > +    committed_size = MIN2(committed_size, size);
> >
> > should it not be rather:
> >
> > +    committed_size = MIN2(committed_size, top - committed_start);
> >
> > ?
> >
> > The code also assumes that the input range starts at the begin of a
> > region. Not sure if this is always the case. So, I would test if
> > MEMORY_BASIC_INFORMATION.BaseAddress lays below the input start
> > address, in which case I would only add the overlapping part to the
> > committed size.
>
> My bad. When I converted the method from thread stack specific one to
> this general one, I did not think through and make corresponding
> changes. Thanks for catching this.
>
> I renamed gtest test to reflect that it is no longer thread stack
> specific, and added test cases for it.
>
> Updated webrev:
> http://cr.openjdk.java.net/~zgu/8199067/webrev.01/index.html
>
> Test:
>    hotspot_runtime and gtest on Linux x64 (fastdebug and release)
>                                 Windows x64 (fastdebug and release)
>
> Thanks,
>
> -Zhengyu
>
>
>
>
>
> >
> > Best Regards, Thomas
> >
> >
> >
> >
> >
> >
> > On Mon, Mar 19, 2018 at 5:10 PM, Zhengyu Gu <zgu at redhat.com> wrote:
> >>
> >> Ping!
> >>
> >> submit-hs test still good.
> >>
> >> Mach5 mach5-one-zgu-JDK-8199067-20180319-1419-14981: Builds PASSED.
> Testing SUCCESSFUL.
> >>
> >> Thanks,
> >>
> >> -Zhengyu
> >>
> >>
> >> On 03/08/2018 09:08 AM, Zhengyu Gu wrote:
> >>>
> >>> The early change failed on some fast machine with many processors
> running Linux OS. It reveals that there can be holes in thread's stack,
> which throws off binary search for finding stack bottom.
> >>>
> >>> Besides, some threads (ConcurrentGCThread and WatcherThread, etc.) do
> exit without notifying NMT, which can trip over NMT final reporting, as
> their stacks became unmapped.
> >>>
> >>> This patch addresses above issues by searching whole address range for
> committed regions. If the address range becomes invalid, simply reports as
> not committed.
> >>>
> >>> GTest also updated.
> >>>
> >>> Bug: https://bugs.openjdk.java.net/browse/JDK-8199067
> >>> Webrev: http://cr.openjdk.java.net/~zgu/8199067/webrev.00/index.html
> >>>
> >>>
> >>> Test:
> >>>     hotspot tier1 on Linux 64 and Windows x64.
> >>>
> >>>     Submit repo test came back clean.
> >>>     Mach5 mach5-one-zgu-JDK-8199067-20180308-1218-13719: Builds
> PASSED. Testing SUCCESSFUL.
> >>>
> >>>
> >>> Thanks,
> >>>
> >>> -Zhengyu
> >>>
>