RFR 8073124: Tune test and document TimSort runs length stack size increase

[Lev Priima]

Thanks, David,
Could you please push it ?

Lev

On 02/16/2015 08:55 AM, David Holmes wrote:
> On 14/02/2015 12:03 AM, Lev Priima wrote:
>> Please review and push:
>> http://cr.openjdk.java.net/~lpriima/8073124/webrev.00/
>> bug: https://bugs.openjdk.java.net/browse/JDK-8073124
>
> I hadn't realized 8072909 had been pushed without final reviewer 
> comments being addressed. :(
>
> These changes seem okay. I hope they get promoted at the same time as 
> the original changeset so we don't get test failures.
>
> Thanks,
> David
>
>> Lev
>>
>> On 02/13/2015 05:20 AM, David Holmes wrote:
>>> Hi Lev,
>>>
>>> On 13/02/2015 2:56 AM, Lev Priima wrote:
>>>> Christos,
>>>>
>>>> Test may fail on shorter arrays(page 8 of paper). For instance, on 
>>>> worst
>>>> case, generated by test, it starts to fail on length 67108864.
>>>> After increasing stack size of runs to merge, Arrays.sort(T[]) works
>>>> also on maximum possible array for HotSpot JVM.
>>>
>>> I'd also like to see this documented somewhere in the code. Presently
>>> there is a reference to listsort.txt but then you have to go and find
>>> it on the web. :( At a minimum could we please add:
>>>
>>>  175          * computation below must be changed if MIN_MERGE is
>>> decreased.  See
>>>  176          * the MIN_MERGE declaration above for more information.
>>> +             * The maximum value of 49 allows for an array up to 
>>> length
>>> +             * Integer.MAX_VALUE-4.
>>>
>>>> Roger, David,
>>>> I've updated the test (
>>>> http://cr.openjdk.java.net/~lpriima/8072909/webrev.01/test/java/util/Arrays/TimSortStackSize2.java.html 
>>>>
>>>>
>>>> ) to make it more suitable for regular execution:
>>>>
>>>>    27  * @run main/othervm TimSortStackSize2 67108864
>>>
>>> This will still fail on small memory devices:
>>>
>>> :~> java TimSortStackSize2 67108864
>>> Exception in thread "main" java.lang.OutOfMemoryError: Java heap space
>>>
>>> as the default heap ergonomics may not be large enough. I had to add a
>>> minimum heap of -Xmx385M to get it to run.
>>>
>>> Thanks,
>>> David
>>>
>>>>    28  * not for regular execution on all platforms:
>>>>    29  * run main/othervm -Xmx8g TimSortStackSize2 1073741824
>>>>    30  * run main/othervm -Xmx32g TimSortStackSize2 2147483644
>>>>
>>>> Could you please push this:
>>>> http://cr.openjdk.java.net/~lpriima/8072909/webrev.01/
>>>> ?
>>>>
>>>> Lev
>>>>
>>>> On 02/12/2015 12:54 PM, christos at zoulas.com wrote:
>>>>> On Feb 12, 9:57pm,david.holmes at oracle.com  (David Holmes) wrote:
>>>>> -- Subject: Re: 8072909: TimSort fails with
>>>>> ArrayIndexOutOfBoundsException on
>>>>>
>>>>> | Ok - thanks Lev!
>>>>> |
>>>>> | David
>>>>>
>>>>> For posterity can someone document this, and also the value for which
>>>>> Integer.MAX_VALUE-4 fails?
>>>>>
>>>>> christos
>>>>
>>