Document Measure Contention

[ssiccha]

Fixes #250.

[ssiccha]

#! gap> n := 4000;; numberBlocks := 8;; q := 5;;
#! gap> A := RandomMat(n, n, GF(q));;
#! gap> GAUSS_MeasureContention(numberBlocks, q, A);
#! Make sure you called GAP with sufficient preallocated memory via `-m` if you
#! try non-trivial examples! Otherwise garbage collection will be a big
#! overhead.
#! 
#! Starting the parallel algorithm
#!     EchelonMatTransformationBlockwise.
#!
#! Wall time  parallel execution (ms): 33940.
#! CPU  time  parallel execution (ms): 2
#! Lock statistics(estimates):
#! acquired - 181502, contended - 1120, ratio - 1.%
#! Locks acquired and contention counters per thread
#! [ thread, locks acquired, locks contended ]:
#! [ 5, 54093, 248 ]
#! [ 6, 51004, 228 ]
#! [ 7, 37102, 389 ]
#! [ 8, 39303, 255 ]
#! 
#! Starting the sequential algorithm
#!     EchelonMatTransformation
#!
#! Wall time Gauss pkg execution (ms): 66778.
#! 
#! Speedup factor (sequential / parallel wall time):
#! 1.96