[Users] cctk_ash versus cctk_lsh

Yosef Zlochower yosef at astro.rit.edu
Tue Oct 21 09:24:55 CDT 2014



On 10/21/2014 10:22 AM, Erik Schnetter wrote:
> Yosef
>
> Yes, I accidentally pointed you to a previous implementation that
> should have been deleted. cacheinfo.cc is the right file to modify.
>
> I assume that you are seeing problems because there is some code that
> still looks at lsh instead of at lsh, probably some boundary condition
> related code. We will need to debug.

Thanks for the help. I'll continue to debug.

One other question. Can I assume that index 0 of a GF
corresponds to CCTK_GFINDEX3D(cctkGH, 0, 0, 0)?


>
> -erik
>
>
> On Tue, Oct 21, 2014 at 10:02 AM, Yosef Zlochower <yosef at astro.rit.edu> wrote:
>> On 10/21/2014 09:39 AM, Erik Schnetter wrote:
>>>
>>> Yes, if VECTORISE_ALIGNED_ARRAYS=no (which is the default), then ash
>>> will be identical to lsh.
>>>
>>> No, there is currently no way to enforce this, although this would be
>>> very good to have for debugging.
>>>
>>> The respective code is in CarpetLib's gdata.cc, bracketed by #if
>>> VECTORISE && VECTORISE_ALIGNED_ARRAYS. To test, you could artificially
>>> add 1 to shape[0] after the line that modifies shape[0].
>>>
>>
>> The above code in gdata.cc seems to be commented out by an #if 0
>>
>>
>>
>> I tried modifying cacheinfo.cc as follows
>>
>> diff --git a/Carpet/CarpetLib/src/cacheinfo.cc
>> b/Carpet/CarpetLib/src/cacheinfo.
>> index c6b33b1..8a68859 100644
>> --- a/Carpet/CarpetLib/src/cacheinfo.cc
>> +++ b/Carpet/CarpetLib/src/cacheinfo.cc
>> @@ -121,8 +121,9 @@ pad_shape(vect<int,D> const& shape)
>>       }   // if pad_to_cachelines
>>   #endif
>>
>> -    padded_shape[d] = npoints;
>> -    accumulated_npoints *= npoints;
>> +#define TEST_PAD 1
>> +    padded_shape[d] = npoints + TEST_PAD*(d==0);
>> +    accumulated_npoints *= npoints + TEST_PAD*(d==0);
>>     }
>>     assert(prod(padded_shape) == accumulated_npoints);
>>
>> This seemed to add padding, but I'm still trying to debug why
>> the result of the test is that for timesteps 1, I get the
>> same results as for no padding, but on timestep 2, I get that
>> every other point in the buffer zone is modified by a small
>> amount (but larger than roundoff), while at iteration
>> 4 nans appear on the symmetry boundary.
>>
>>
>>
>>> -erik
>>>
>>> On Tue, Oct 21, 2014 at 8:59 AM, Yosef Zlochower <yosef at astro.rit.edu>
>>> wrote:
>>>>
>>>> Hi,
>>>>
>>>>      Is it the case that cctk_ash[i] = cctk_lsh[i] (i=0..3)
>>>> if  VECTORISE_ALIGNED_ARRAYS= no? I want to update and
>>>> test  a code that assumed the GF sizes were
>>>> given by cctk_lsh. Is there a way to force
>>>> cctk_ash to be larger than cctk_lsh in order
>>>> to test the update.
>>>>
>>>> Thanks
>>>>
>>>> --
>>>> Dr. Yosef Zlochower
>>>> Center for Computational Relativity and Gravitation
>>>> Associate Professor
>>>> School of Mathematical Sciences
>>>> Rochester Institute of Technology
>>>> 85 Lomb Memorial Drive
>>>> Rochester, NY 14623
>>>>
>>>> Office:74-2067
>>>> Phone: +1 585-475-6103
>>>>
>>>> yosef at astro.rit.edu
>>>>
>>>> CONFIDENTIALITY NOTE: The information transmitted, including
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>>>
>>>
>>>
>>>
>>
>>
>> --
>> Dr. Yosef Zlochower
>> Center for Computational Relativity and Gravitation
>> Associate Professor
>> School of Mathematical Sciences
>> Rochester Institute of Technology
>> 85 Lomb Memorial Drive
>> Rochester, NY 14623
>>
>> Office:74-2067
>> Phone: +1 585-475-6103
>>
>> yosef at astro.rit.edu
>>
>> CONFIDENTIALITY NOTE: The information transmitted, including
>> attachments, is intended only for the person(s) or entity to which it
>> is addressed and may contain confidential and/or privileged material.
>> Any review, retransmission, dissemination or other use of, or taking
>> of any action in reliance upon this information by persons or entities
>> other than the intended recipient is prohibited. If you received this
>> in error, please contact the sender and destroy any copies of this
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>
>
>


-- 
Dr. Yosef Zlochower
Center for Computational Relativity and Gravitation
Associate Professor
School of Mathematical Sciences
Rochester Institute of Technology
85 Lomb Memorial Drive
Rochester, NY 14623

Office:74-2067
Phone: +1 585-475-6103

yosef at astro.rit.edu

CONFIDENTIALITY NOTE: The information transmitted, including
attachments, is intended only for the person(s) or entity to which it
is addressed and may contain confidential and/or privileged material.
Any review, retransmission, dissemination or other use of, or taking
of any action in reliance upon this information by persons or entities
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