RFR: 8169931: 8k class metaspace chunks misallocated from 4k chunk freelist
stefan.karlsson at oracle.com
Tue Nov 22 21:05:10 UTC 2016
On 2016-11-22 20:30, Coleen Phillimore wrote:
> Can you put this test at the end of the file with // Unit Tests and an
> explanation why this is here so people don't try to port the whole
> thing to gtest?
> I was looking for uses of list_index and found this code, which looks
> assert((word_size <= chunk->word_size()) ||
> list_index(chunk->word_size() == HumongousIndex),
> "Non-humongous variable sized chunk");
I'll fix that assert.
> This change looks good though.
Thanks, I'll send out a new patch.
> On 11/22/16 9:54 AM, Stefan Karlsson wrote:
>> Hi all,
>> Please, review this patch to fix a bug in ChunkManager::list_index():
>> There's a great description of the bug in the bug report:
>> There are two conceptual parts of the metaspace. The _class_
>> metaspace, and the _non-class_ metaspace. They have different chunk
>> sizes, and while querying for the list index of a humongous chunk in
>> the class metaspace, the code accidentally matched the size against
>> the MediumChunk size of the non-class metaspace.
>> I've changed the code to not query against the global ChunkSizes
>> enum, but rather the values stored inside the ChunkManager instances.
>> Therefore, the list_index() function was changed into an instance
>> I've written a unit test that provoked the bug. It's a simplified
>> test with vm asserts instead of gtest asserts. The reason is that the
>> ChunkManager class is currently located in metaspace.cpp, and is not
>> accessible from the gtest unit tests.
>> Testing: jprt, Kitchensink, parallel class loading tests
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