[SYSTEMML-2016] Performance frame cbind and vector frame casts (shallow) This patch makes major performance improvements to the frame primitives cbind and matrix (special case of vector) to frame casts, which both can be done via shallow copies. This is safe due to copy-on-write semantics of operations.
On a scenario of 20 iterations of cbind(as.frame(X), cbind(as.frame(Y), as.frame(Z))) over 10M x 1 dense inputs, this patch improved end-to-end runtime from 26.1s (15s GC) to 3.9s (0.2s GC). Note that 90% of remaining execution time is spent in buffer pool evictions, which are unnecessary and will be addressed in a subsequent patch. Project: http://git-wip-us.apache.org/repos/asf/systemml/repo Commit: http://git-wip-us.apache.org/repos/asf/systemml/commit/1e0a4151 Tree: http://git-wip-us.apache.org/repos/asf/systemml/tree/1e0a4151 Diff: http://git-wip-us.apache.org/repos/asf/systemml/diff/1e0a4151 Branch: refs/heads/master Commit: 1e0a4151d21d0821668dd7d0de34ac6b75c33358 Parents: 9e599cd Author: Matthias Boehm <mboe...@gmail.com> Authored: Wed Nov 15 22:38:24 2017 -0800 Committer: Matthias Boehm <mboe...@gmail.com> Committed: Thu Nov 16 00:11:52 2017 -0800 ---------------------------------------------------------------------- .../RewriteAlgebraicSimplificationStatic.java | 2 +- .../apache/sysml/runtime/matrix/data/FrameBlock.java | 8 +++----- .../org/apache/sysml/runtime/util/DataConverter.java | 15 +++++++++++---- 3 files changed, 15 insertions(+), 10 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/systemml/blob/1e0a4151/src/main/java/org/apache/sysml/hops/rewrite/RewriteAlgebraicSimplificationStatic.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/sysml/hops/rewrite/RewriteAlgebraicSimplificationStatic.java b/src/main/java/org/apache/sysml/hops/rewrite/RewriteAlgebraicSimplificationStatic.java index d71c4e0..cc2fe88 100644 --- a/src/main/java/org/apache/sysml/hops/rewrite/RewriteAlgebraicSimplificationStatic.java +++ b/src/main/java/org/apache/sysml/hops/rewrite/RewriteAlgebraicSimplificationStatic.java @@ -522,7 +522,7 @@ public class RewriteAlgebraicSimplificationStatic extends HopRewriteRule private static Hop foldMultipleAppendOperations(Hop hi) throws HopsException { - if( hi.getDataType().isMatrix() //no string appends + if( hi.getDataType().isMatrix() //no string appends or frames && (HopRewriteUtils.isBinary(hi, OpOp2.CBIND, OpOp2.RBIND) || HopRewriteUtils.isNary(hi, OpOpN.CBIND, OpOpN.RBIND)) && !OptimizerUtils.isHadoopExecutionMode() ) http://git-wip-us.apache.org/repos/asf/systemml/blob/1e0a4151/src/main/java/org/apache/sysml/runtime/matrix/data/FrameBlock.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/sysml/runtime/matrix/data/FrameBlock.java b/src/main/java/org/apache/sysml/runtime/matrix/data/FrameBlock.java index a56fd6a..e83b362 100644 --- a/src/main/java/org/apache/sysml/runtime/matrix/data/FrameBlock.java +++ b/src/main/java/org/apache/sysml/runtime/matrix/data/FrameBlock.java @@ -471,9 +471,9 @@ public class FrameBlock implements Writable, CacheBlock, Externalizable for( int j=0; j<ncol; j++ ) tmpData[j] = new DoubleArray(cols[j]); _colnames = empty ? null : (String[]) ArrayUtils.addAll(getColumnNames(), - createColNames(getNumColumns(), ncol)); //before schema modification + createColNames(getNumColumns(), ncol)); //before schema modification _schema = empty ? tmpSchema : (ValueType[]) ArrayUtils.addAll(_schema, tmpSchema); - _coldata = empty ? tmpData : (Array[]) ArrayUtils.addAll(_coldata, tmpData); + _coldata = empty ? tmpData : (Array[]) ArrayUtils.addAll(_coldata, tmpData); _numRows = cols[0].length; } @@ -988,10 +988,8 @@ public class FrameBlock implements Writable, CacheBlock, Externalizable ret._colnames = (String[]) ArrayUtils.addAll(getColumnNames(), that.getColumnNames()); ret._colmeta = (ColumnMetadata[]) ArrayUtils.addAll(_colmeta, that._colmeta); - //concatenate column data (w/ deep copy to prevent side effects) + //concatenate column data (w/ shallow copy which is safe due to copy on write semantics) ret._coldata = (Array[]) ArrayUtils.addAll(_coldata, that._coldata); - for( int i=0; i<ret.getNumColumns(); i++ ) - ret._coldata[i] = ret._coldata[i].clone(); } else //ROW APPEND { http://git-wip-us.apache.org/repos/asf/systemml/blob/1e0a4151/src/main/java/org/apache/sysml/runtime/util/DataConverter.java ---------------------------------------------------------------------- diff --git a/src/main/java/org/apache/sysml/runtime/util/DataConverter.java b/src/main/java/org/apache/sysml/runtime/util/DataConverter.java index af69e81..bfc07ba 100644 --- a/src/main/java/org/apache/sysml/runtime/util/DataConverter.java +++ b/src/main/java/org/apache/sysml/runtime/util/DataConverter.java @@ -654,7 +654,7 @@ public class DataConverter if( mb.isInSparseFormat() ) //SPARSE { - SparseBlock sblock = mb.getSparseBlock(); + SparseBlock sblock = mb.getSparseBlock(); for( int i=0; i<mb.getNumRows(); i++ ) { Arrays.fill(row, null); //reset if( sblock != null && !sblock.isEmpty(i) ) { @@ -664,7 +664,7 @@ public class DataConverter double[] aval = sblock.values(i); for( int j=apos; j<apos+alen; j++ ) { row[aix[j]] = UtilFunctions.doubleToObject( - schema[aix[j]], aval[j]); + schema[aix[j]], aval[j]); } } frame.appendRow(row); @@ -673,8 +673,15 @@ public class DataConverter else //DENSE { int dFreq = UtilFunctions.frequency(schema, ValueType.DOUBLE); - - if( dFreq == schema.length ) { + + if( schema.length==1 && dFreq==1 && mb.isAllocated() ) { + // special case double schema and single columns which + // allows for a shallow copy since the physical representation + // of row-major matrix and column-major frame match exactly + frame.reset(); + frame.appendColumns(new double[][]{mb.getDenseBlock()}); + } + else if( dFreq == schema.length ) { // special case double schema (without cell-object creation, // col pre-allocation, and cache-friendly row-column copy) int m = mb.getNumRows();
