
Solving linear systems with GMRES and CG methods on GPU clusters 321
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Sparse global vector
Sparse submatrix
Reordering of
the submatrix
subvector subvector
local shared
Reordered sparse
submatrix
storage format
Global vector in compressed
FIGURE 13.3. Columns reordering of a sparse submatrix.
indices in the global vector. So as not to need to perform this at each iter-
ation, we propose to reorder the columns of each submatrix {A
i
}
0≤i<p
, so
that the shared subvectors could be used in their compressed storage formats.
Figure 13.3