[ltt-dev] [PATCH] Fixing bugs in cluster synchronisation for accuracy algorithm

[compudj@krystal.dyndns.org (Mathieu Desnoyers)]

* masoume.jabbarifar at polymtl.ca (masoume.jabbarifar at polymtl.ca) wrote:
> From: Masoume Jabbarifar <masoume.jabbarifar@polymtl.ca>
> 

Can you document the change in the patch header ?

Also, please CC Benjamin on these changes. I'd like him to have a look
at them if he has time.

> ---
>  lttv/lttv/sync/data_structures.h           |    2 +-
>  lttv/lttv/sync/factor_reduction_accuracy.c |   15 ++++++++++++---
>  lttv/lttv/sync/sync_chain_lttv.c           |   18 ++++++++++++------
>  lttv/lttv/sync/sync_chain_unittest.c       |    9 ++++++---
>  4 files changed, 31 insertions(+), 13 deletions(-)
> 
> diff --git a/lttv/lttv/sync/data_structures.h b/lttv/lttv/sync/data_structures.h
> index 627286c..2206455 100644
> --- a/lttv/lttv/sync/data_structures.h
> +++ b/lttv/lttv/sync/data_structures.h
> @@ -131,7 +131,7 @@ typedef struct
>   * synchronization */
>  typedef struct
>  {
> -	double drift, offset;
> +	double drift, offset, accuracyToRefNode;

Hrm, I see that the sync code use a different coding style than the rest
of lttv. *sight* OK then.

For your information, the rest of lttv uses lower cases for variable
identifiers, and UpperCase for type identifiers. It also uses
lower_case_with_underscore() for function names.

>  } Factors;
>  
>  // Correction factors between trace pairs, to be used for reduction
> diff --git a/lttv/lttv/sync/factor_reduction_accuracy.c b/lttv/lttv/sync/factor_reduction_accuracy.c
> index a63dae7..bf0546b 100644
> --- a/lttv/lttv/sync/factor_reduction_accuracy.c
> +++ b/lttv/lttv/sync/factor_reduction_accuracy.c
> @@ -415,12 +415,19 @@ static void getFactors(AllFactors* const allFactors, unsigned int** const
>  	unsigned int reference;
>  	PairFactors** const pairFactors= allFactors->pairFactors;
>  
> -	reference= references[traceNum];
> -
> +	if (traceNum == references[traceNum])
> +	{
> +		reference=traceNum;
> +	}
> +	else
> +	{
> +		reference = predecessors[references[traceNum]][traceNum];
> +	}
>  	if (reference == traceNum)
>  	{
>  		factors->offset= 0.;
>  		factors->drift= 1.;
> +		factors->accuracyToRefNode= 0.;
>  	}
>  	else
>  	{
> @@ -428,6 +435,8 @@ static void getFactors(AllFactors* const allFactors, unsigned int** const
>  
>  		getFactors(allFactors, predecessors, references,
>  			predecessors[reference][traceNum], &previousVertexFactors);
> +		factors->accuracyToRefNode = 
> +			pairFactors[reference][traceNum].accuracy+ pairFactors[traceNum][reference].accuracy + previousVertexFactors.accuracyToRefNode;
>  
>  		/* Convert the time from traceNum to reference;
>  		 * pairFactors[row][col] converts the time from col to row, invert the
> @@ -452,7 +461,7 @@ static void getFactors(AllFactors* const allFactors, unsigned int** const
>  		}
>  		else
>  		{
> -			g_assert_not_reached();
> +			//g_assert_not_reached();

Why commenting this ? This assertion was probably there for a reason.
Shutting up assertions without proper comments is usually a bad
practice, as assertions are our safety nets.

>  		}
>  	}
>  }
> diff --git a/lttv/lttv/sync/sync_chain_lttv.c b/lttv/lttv/sync/sync_chain_lttv.c
> index 95bef44..20ed111 100644
> --- a/lttv/lttv/sync/sync_chain_lttv.c
> +++ b/lttv/lttv/sync/sync_chain_lttv.c
> @@ -218,6 +218,7 @@ bool syncTraceset(LttvTracesetContext* const traceSetContext)
>  	double minOffset, minDrift;
>  	unsigned int refFreqTrace;
>  	int retval;
> +	double sumAccuracy;
>  
>  	if (!optionSync.present)
>  	{
> @@ -370,8 +371,6 @@ bool syncTraceset(LttvTracesetContext* const traceSetContext)
>  					t->drift * t->start_tsc + t->offset));
>  	}
>  
> -	g_array_free(factors, TRUE);
> -
>  	lttv_traceset_context_compute_time_span(traceSetContext,
>  		&traceSetContext->time_span);
>  
> @@ -395,21 +394,28 @@ bool syncTraceset(LttvTracesetContext* const traceSetContext)
>  	if (!optionSyncNull.present && optionSyncStats.present)
>  	{
>  		printStats(syncState);
> -
> +		sumAccuracy = 0;

  = 0.;

>  		printf("Resulting synchronization factors:\n");
>  		for (i= 0; i < syncState->traceNb; i++)
>  		{
>  			LttTrace* t;
> +			Factors* traceFactors;
>  
>  			t= traceSetContext->traces[i]->t;
> -
> -			printf("\ttrace %u drift= %g offset= %g (%f) start time= %ld.%09ld\n",
> +			traceFactors= &g_array_index(factors, Factors, i);
> +			
> +			printf("\ttrace %u drift= %g offset= %g (%f) start time= %ld.%09ld accuracyToRefNode= %g\n",
>  				i, t->drift, t->offset, (double) tsc_to_uint64(t->freq_scale,
>  					t->start_freq, t->offset) / NANOSECONDS_PER_SECOND,
>  				t->start_time_from_tsc.tv_sec,
> -				t->start_time_from_tsc.tv_nsec);
> +				t->start_time_from_tsc.tv_nsec,traceFactors->accuracyToRefNode);
> +			sumAccuracy += traceFactors->accuracyToRefNode;
> +
>  		}
>  	}
> +	printf("Total accuracy (0.0 is the best): %g\n",sumAccuracy);
> +
> +	g_array_free(factors, TRUE);
>  
>  	syncState->processingModule->destroyProcessing(syncState);
>  	if (syncState->matchingModule != NULL)
> diff --git a/lttv/lttv/sync/sync_chain_unittest.c b/lttv/lttv/sync/sync_chain_unittest.c
> index 40302a0..d59eb09 100644
> --- a/lttv/lttv/sync/sync_chain_unittest.c
> +++ b/lttv/lttv/sync/sync_chain_unittest.c
> @@ -114,6 +114,7 @@ int main(const int argc, char* const argv[])
>  	GString* analysisModulesNames;
>  	GString* reductionModulesNames;
>  	unsigned int id;
> +	double sumAccuracy;
>  	AllFactors* allFactors;
>  
>  	/*
> @@ -266,15 +267,17 @@ int main(const int argc, char* const argv[])
>  		unsigned int i;
>  
>  		printStats(syncState);
> -
> +		sumAccuracy = 0;

 = 0.;

Thanks,

Mathieu

>  		printf("Resulting synchronization factors:\n");
>  		for (i= 0; i < factors->len; i++)
>  		{
>  			Factors* traceFactors= &g_array_index(factors, Factors, i);
> -			printf("\ttrace %u drift= %g offset= %g\n", i,
> -				traceFactors->drift, traceFactors->offset);
> +			printf("\ttrace %u drift= %g offset= %g accuracyToRefNode= %g\n", i,
> +				traceFactors->drift, traceFactors->offset, traceFactors->accuracyToRefNode);
> +			sumAccuracy += traceFactors->accuracyToRefNode;
>  		}
>  	}
> +	printf("Total accuracy (0.0 is the best): %g\n",sumAccuracy);
>  
>  	// Destroy modules and clean up
>  	syncState->processingModule->destroyProcessing(syncState);
> -- 
> 1.6.0.4
> 
> 
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> 

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com