[SCIP] locking while separating

[Gerald Gamrath]

Hi James,

nice to hear that you figured out what the problem was. It's strange 
that the SCIP_CALL seems to mess up your profiling, I did not experience 
this before. Did you do the profiling using the OPT=prf option?

Recently, I prefer using valgrind --tool=callgrind. It is quite slow, 
but gives you good output, you can even use the opt-mode, but should 
compile with USROFLAGS="-g".

Best,
Gerald

On 07.03.2016 10:03, James Cussens wrote:
> Dear Gerald,
>
> I finally got to the bottom of this. Some of the functions my 
> "ChordalSeparate" function was calling returned SCIP_RETCODE and were 
> wrapped inside a SCIP_CALL. These functions did not appear
> in the output from the profile. I altered them to be 'normal' 
> functions and called them without the SCIP_CALL wrapping. After doing 
> this they appeared as expected in the profile output and my constraint 
> handler's
> lock method ( consLockChordal ) only showed up as being called twice. 
> So everything now makes sense.
>
> One thing perhaps noting, my original approach - where the functions 
> were wrapped inside a SCIP_CALL - was a bit silly: there was no point 
> doing this wrapping and the SCIP* pointer I sent to the functions
> was not even used in them. (An earlier version had done some 
> SCIPallocMemoryArray calls but I then removed these.) Perhaps this 
> weird code somehow confused the profiling.
>
> James
>
>
>
> On 1 March 2016 at 22:52, Gerald Gamrath <gamrath at zib.de 
> <mailto:gamrath at zib.de>> wrote:
>
>     Dear James,
>
>     this looks unexpected. Your separator adds constraints of your
>     constraints handler and no rows? Then, the CONSLOCK callback of
>     your constraint handler is called whenever a constraint is added
>     to update the rounding locks of variables in the constraint. Could
>     there be a performance issue in that CALLBACK implementation?
>
>     Best,
>     Gerald
>
>     Am 28.02.2016 um 17:14 schrieb James Cussens:
>>     I have implemented a separator for a constraint handler I have
>>     written. When profiling I find that most of the time is spent
>>     when my separator calls my constraint hander's lock method:
>>
>>                                      2 SCIPconsAddLocks <cycle 2> [2184]
>>                                  257328483     ChordalSeparate <cycle
>>     2> [19]
>>     [3]     49.2   27.00    0.64 257328485 consLockChordal <cycle 2> [3]
>>                     0.35    0.00 110035069/224944534    
>>     BMSreallocMemoryArray_call [45]
>>                     0.29    0.00 147293414/176070304    
>>     BMSallocMemoryArray_call [61]
>>                     0.00    0.00    1332/12022817   readNextLine [147]
>>                     0.00    0.00    1332/262849  get_edge [2084]
>>                                      498   SCIPaddVarLocks <cycle 2>
>>     [2102]
>>
>>     I'm not sure why this is happening. Can anyone enlighten me?
>>
>>     Thanks,
>>
>>     James
>>
>>     -- 
>>     James Cussens
>>     Dept of Computer Science &
>>     York Centre for Complex Systems Analysis
>>     Room 326, The Hub, Deramore Lane            Tel  +44 (0)1904 325371
>>     University of York        Fax +44 (0)1904 500159
>>     <tel:%2B44%20%280%291904%20500159>
>>     York YO10 5GE, UK http://www.cs.york.ac.uk/~jc
>>     <http://www.cs.york.ac.uk/%7Ejc>
>>     http://www.york.ac.uk/docs/disclaimer/email.htm
>>
>>
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>
>
>
>
> -- 
> James Cussens
> Dept of Computer Science &
> York Centre for Complex Systems Analysis
> Room 326, The Hub, Deramore Lane            Tel    +44 (0)1904 325371
> University of York                                        Fax  +44 
> (0)1904 500159
> York YO10 5GE, UK http://www.cs.york.ac.uk/~jc 
> <http://www.cs.york.ac.uk/%7Ejc>
> http://www.york.ac.uk/docs/disclaimer/email.htm

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