RFR(S): 8058897 - Unsafe.reallocateMemory() ignores -XX:MallocMaxTestWords setting.
Daniel D. Daugherty
daniel.daugherty at oracle.com
Wed Jan 7 14:47:26 UTC 2015
On 1/6/15 5:12 PM, Christian Tornqvist wrote:
> Hi everyone,
>
>
>
> This change makes realloc use MallocMaxTestWords, a debug option used to
> simulate malloc OOM.
>
>
>
> Webrev:
>
> http://cr.openjdk.java.net/~ctornqvi/webrev/8058897/webrev.00/
src/share/vm/runtime/os.cpp
The old testMalloc() function would increment cur_malloc_words only
if the underlying ::malloc() call succeeded. This was intentional.
The switch to has_reached_max_malloc_test_peak() followed by the
::malloc() call means that an intentionally large failing ::malloc()
call will result in falsely reaching the test peak.
test/runtime/Unsafe/Reallocate.java
Should this test have an @bug entry?
line 59: unsafe.reallocateMemory(address, 20 * 1000 * 1000 * 8);
Shouldn't this be "1024 * 1024" instead of "1000 * 1000"?
Also, -XX:MallocMaxTestWords=20m means 20m words and not
20m bytes so the "* 8" part might not always cause an OOM.
Dan
>
>
>
> Bug:
>
> https://bugs.openjdk.java.net/browse/JDK-8058897
>
>
>
> Thanks,
>
> Christian
>
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