RFR 8234270: [REDO] JDK-8204128 NMT might report incorrect numbers for Compiler area
Zhengyu Gu
zgu at redhat.com
Tue Nov 26 14:29:40 UTC 2019
>>
>> But I leave it up tp you if you change this. If you just reorder the
>> calls, I do not need another Webrev,
>
> I will re-order the calls, as you suggested.
Passed submit tests and pushed.
Thanks, Thomas and Yumin
-Zhengyu
>
> Thanks,
>
> -Zhengyu
>
>>
>> ...
>>
>> Another unrelated question, what is the reason for the unusual
>> creation of MallocMemorySummarySnapshot with placement new? Why not
>> just put it as a member into MallocMemorySummary? I must be missing
>> something.
>>
>>
>> -Zhengyu
>>
>>
>>
>> >
>> > 66 wb.NMTFreeArena(arena1);
>> >
>> > On Mon, Nov 25, 2019 at 2:30 PM Zhengyu Gu <zgu at redhat.com
>> <mailto:zgu at redhat.com>
>> > <mailto:zgu at redhat.com <mailto:zgu at redhat.com>>> wrote:
>> >
>> > Ping ... May I get a second review?
>> >
>> > Thanks,
>> >
>> > -Zhengyu
>> >
>> > On 11/21/19 12:12 PM, yumin qi wrote:
>> > > Hi, Zhengyu
>> > >
>> > > The fix looks good to me.
>> > >
>> > > Thanks
>> > > Yumin
>> > >
>> > >
>> > >
>> > > On Wed, Nov 20, 2019 at 5:49 AM Zhengyu Gu <zgu at redhat.com
>> <mailto:zgu at redhat.com>
>> > <mailto:zgu at redhat.com <mailto:zgu at redhat.com>>
>> > > <mailto:zgu at redhat.com <mailto:zgu at redhat.com>
>> <mailto:zgu at redhat.com <mailto:zgu at redhat.com>>>> wrote:
>> > >
>> > > JDK-8204128 did not fix the original bug. But new
>> assertion
>> > helped to
>> > > catch the problem, as it consistently failed in Oracle
>> > internal tests.
>> > >
>> > > The root cause is that, when NMT biases a resource
>> area to
>> > compiler, it
>> > > did not adjust tracking data to reflect that. When the
>> biased
>> > resource
>> > > area is released, there is a possibility that its
>> size is
>> > greater than
>> > > total size recorded, and underflow a size_t counter.
>> > >
>> > > JDK-8204128 patch also missed a long to ssize_t
>> parameter
>> > type change,
>> > > that resulted new test failure on Windows, because
>> long is
>> > 4-bytes on
>> > > Windows.
>> > >
>> > > Many thanks to Leonid Mesnik, who helped to run this
>> patch
>> > through
>> > > Oracle's internal stress tests.
>> > >
>> > > Bug: https://bugs.openjdk.java.net/browse/JDK-8234270
>> > > Webrev:
>> > http://cr.openjdk.java.net/~zgu/JDK-8234270/webrev.00/index.html
>> > >
>> > >
>> > > Test:
>> > > hotspot_nmt
>> > > Submit test
>> > > Oracle internal stress tests.
>> > >
>> > >
>> > > Thanks,
>> > >
>> > > -Zhengyu
>> > >
>> >
>>
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