Hi everyone,
> Hi everyone,
>
> I am running into bugs in a multi-locale Chapel program and came across the
> following in $CHPL_HOME/STATUS:
>
> - The --gdb flag is only supported for single-locale platforms that
> support gdb. Please ask us for help if you want to debug a
> multilocale program.
>
> That being said, I would like to know what options I have to debug a
> multi-locale Chapel program and how to use these options.
>
> The specific problems I think I am encountering in my multi-locale program
> have to do with the chpl_comm_get_strd and chpl_comm_put_strd communication
> calls. I want to split a single get or put call into multiple calls to
> conserve memory on a locale. The following code shows a single call
> (assuming parameters are declared beforehand):
>
> //copy remote data to local buffer
> __primitive("chpl_comm_get_strd",
> __primitive("array_get", dest, buf._value.getDataIndex(1)),
> __primitive("array_get",dststr,dstStride._value.getDataIndex(1)),
> rid,
> __primitive("array_get", src,
> arrSection.myElems._value.getDataIndex(myFollowThis.low)),
> __primitive("array_get",srcstr,srcStride._value.getDataIndex(1)),
> __primitive("array_get",cnt, count._value.getDataIndex(1)),
> stridelevels);
Regarding the strided get call in my previous message, what does each
"array_get" call mean semantically? For example, the __primitive("array_get",
src, arrSection.myElems._value.getDataIndex(myFollowThis.low)). I understand
vaguely that this call determines the source pointer at which to start from
when communicating remote data, but that is about it. If I wanted to start from
another source pointer (some offset from the original source pointer) that is
determined dynamically at runtime, how might I do this? Any further help in
understanding this would be appreciated. Here is the full code portion that
might be useful in answering my question:
var buf: [1..bufsize] this.eltType;
var dest = buf._value.theData;
const src = arrSection.myElems._value.theData;
const rid=arrSection.locale.id;
var dststr=dstStride._value.theData;
var srcstr=srcStride._value.theData;
var cnt=bounded_count._value.theData;
//copy remote data to local buffer
__primitive("chpl_comm_get_strd",
__primitive("array_get", dest, buf._value.getDataIndex(1)),
__primitive("array_get",dststr,dstStride._value.getDataIndex(1)),
rid,
__primitive("array_get", src,
arrSection.myElems._value.getDataIndex(myFollowThis.low)),
__primitive("array_get",srcstr,srcStride._value.getDataIndex(1)),
__primitive("array_get",cnt, bounded_count._value.getDataIndex(1)),
stridelevels);
Aroon Sharma
University of Maryland, Class of 2015
M.S. Computer Engineering
(301) 908-9528
On Wednesday, January 22, 2014 3:31 PM, Rafael Larrosa Jiménez
<[email protected]> wrote:
Hi,
> Hi everyone,
>
> I am running into bugs in a multi-locale Chapel program and came across the
> following in $CHPL_HOME/STATUS:
>
> - The --gdb flag is only supported for single-locale platforms that
> support gdb. Please ask us for help if you want to debug a
> multilocale program.
>
> That being said, I would like to know what options I have to debug a
> multi-locale Chapel program and how to use these options.
>
> The specific problems I think I am encountering in my multi-locale program
> have to do with the chpl_comm_get_strd and chpl_comm_put_strd communication
> calls. I want to split a single get or put call into multiple calls to
> conserve memory on a locale. The following code shows a single call
> (assuming parameters are declared beforehand):
>
> //copy remote data to local buffer
> __primitive("chpl_comm_get_strd",
> __primitive("array_get", dest, buf._value.getDataIndex(1)),
> __primitive("array_get",dststr,dstStride._value.getDataIndex(1)),
> rid,
> __primitive("array_get", src,
> arrSection.myElems._value.getDataIndex(myFollowThis.low)),
> __primitive("array_get",srcstr,srcStride._value.getDataIndex(1)),
> __primitive("array_get",cnt, count._value.getDataIndex(1)),
> stridelevels);
If you are using the trunk, one problem can be that you need to use
getUnshiftedDataIndex in the pointers to source and destination instead of
getDataIndex.
Also I have found quite useful to activate the bounds checker for the programs
with:
--bounds-checks --local-checks --nil-checks --debug
And it can help also to wrap those primitive calls with :
startVerboseComm();
__primitive("chpl_comm_get_strd",....
stopVerboseComm();
Hope this helps,
Rafael
> with the following semantics:
>
> __primitive("chpl_comm_get_strd",
> pointer to source,
> source strides,
> remote locale id,
> pointer to destination,
> destination strides,
> copy length,
> number of dimensions
> );
>
> Any suggestions or documentation relating to either of these topics would be
> helpful.
> Aroon Sharma
> University of Maryland, Class of 2015
> M.S. Computer Engineering
> (301) 908-9528
--
Rafael Larrosa Jiménez
Centro de Supercomputación y Bioinformática - http://www.scbi.uma.es
Universidad de Málaga
EMAIL: [email protected] Edificio de Bioinnovación
TELEF: + 34951952788 C/ Severo Ochoa 34
FAX : +34951952792 Parque Tecnológico de Andalucía
29590 Málaga (SPAIN)------------------------------------------------------------------------------
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