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Posted to commits@systemml.apache.org by mb...@apache.org on 2017/10/16 22:38:53 UTC
[2/3] systemml git commit: [SYSTEMML-1836] Fix unnecessary GC
overhead in codegen row operations
[SYSTEMML-1836] Fix unnecessary GC overhead in codegen row operations
This patch fixes issues of huge garbage collection overhead in special
cases of codegen row operations with relatively large intermediate rows,
matrix side inputs, and especially for multi-threaded operations. The
major problem was that, for aggregations, the temporary output per
thread was allocated as the product of the two temporary vector sizes
(as necessary for matrix multiplication outputs), which however is often
completely unnecessary.
On a scenario of row operations for sum( (X != 0) * (UV - X) ^ 2) over
small inputs of 10K x 3K, this patch improved performance for 10
iterations from 80s (74s GC) to 1.4s (0.074s GC).
Project: http://git-wip-us.apache.org/repos/asf/systemml/repo
Commit: http://git-wip-us.apache.org/repos/asf/systemml/commit/586f8229
Tree: http://git-wip-us.apache.org/repos/asf/systemml/tree/586f8229
Diff: http://git-wip-us.apache.org/repos/asf/systemml/diff/586f8229
Branch: refs/heads/master
Commit: 586f82299292019583b68dd98ccb8fbb71a2fcd3
Parents: b6b6772
Author: Matthias Boehm <mb...@gmail.com>
Authored: Sun Oct 15 21:50:17 2017 -0700
Committer: Matthias Boehm <mb...@gmail.com>
Committed: Sun Oct 15 21:50:17 2017 -0700
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.../sysml/runtime/codegen/LibSpoofPrimitives.java | 11 +++++++++--
.../apache/sysml/runtime/codegen/SpoofRowwise.java | 14 +++++++-------
2 files changed, 16 insertions(+), 9 deletions(-)
----------------------------------------------------------------------
http://git-wip-us.apache.org/repos/asf/systemml/blob/586f8229/src/main/java/org/apache/sysml/runtime/codegen/LibSpoofPrimitives.java
----------------------------------------------------------------------
diff --git a/src/main/java/org/apache/sysml/runtime/codegen/LibSpoofPrimitives.java b/src/main/java/org/apache/sysml/runtime/codegen/LibSpoofPrimitives.java
index 8444b5f..7624d96 100644
--- a/src/main/java/org/apache/sysml/runtime/codegen/LibSpoofPrimitives.java
+++ b/src/main/java/org/apache/sysml/runtime/codegen/LibSpoofPrimitives.java
@@ -1829,9 +1829,9 @@ public class LibSpoofPrimitives
private int _len2;
public VectorBuffer(int num, int len1, int len2) {
- int lnum = (len2 > 0) ? 2*num : num;
+ int lnum = (len2>0 && len1!=len2) ? 2*num : num;
_data = new double[lnum][];
- for( int i=0; i<num; i++ )
+ for( int i=0; i<num; i++ ) {
if( lnum > num ) {
_data[2*i] = new double[len1];
_data[2*i+1] = new double[len2];
@@ -1839,6 +1839,7 @@ public class LibSpoofPrimitives
else {
_data[i] = new double[len1];
}
+ }
_pos = -1;
_len1 = len1;
_len2 = len2;
@@ -1851,5 +1852,11 @@ public class LibSpoofPrimitives
} while( _data[_pos].length!=len );
return _data[_pos];
}
+ @SuppressWarnings("unused")
+ public boolean isReusable(int num, int len1, int len2) {
+ int lnum = (len2>0 && len1!=len2) ? 2*num : num;
+ return (_len1 == len1 && _len2 == len2
+ && _data.length == lnum);
+ }
}
}
http://git-wip-us.apache.org/repos/asf/systemml/blob/586f8229/src/main/java/org/apache/sysml/runtime/codegen/SpoofRowwise.java
----------------------------------------------------------------------
diff --git a/src/main/java/org/apache/sysml/runtime/codegen/SpoofRowwise.java b/src/main/java/org/apache/sysml/runtime/codegen/SpoofRowwise.java
index d8a747b..9d5675b 100644
--- a/src/main/java/org/apache/sysml/runtime/codegen/SpoofRowwise.java
+++ b/src/main/java/org/apache/sysml/runtime/codegen/SpoofRowwise.java
@@ -209,8 +209,9 @@ public abstract class SpoofRowwise extends SpoofOperator
if( _type.isColumnAgg() || _type == RowType.FULL_AGG ) {
//execute tasks
ArrayList<ParColAggTask> tasks = new ArrayList<>();
+ int outLen = out.getNumRows() * out.getNumColumns();
for( int i=0; i<nk & i*blklen<m; i++ )
- tasks.add(new ParColAggTask(a, b, scalars, n, n2, i*blklen, Math.min((i+1)*blklen, m)));
+ tasks.add(new ParColAggTask(a, b, scalars, n, n2, outLen, i*blklen, Math.min((i+1)*blklen, m)));
List<Future<double[]>> taskret = pool.invokeAll(tasks);
//aggregate partial results
int len = _type.isColumnAgg() ? out.getNumRows()*out.getNumColumns() : 1;
@@ -343,17 +344,16 @@ public abstract class SpoofRowwise extends SpoofOperator
private final MatrixBlock _a;
private final SideInput[] _b;
private final double[] _scalars;
- private final int _clen;
- private final int _clen2;
- private final int _rl;
- private final int _ru;
+ private final int _clen, _clen2, _outLen;
+ private final int _rl, _ru;
- protected ParColAggTask( MatrixBlock a, SideInput[] b, double[] scalars, int clen, int clen2, int rl, int ru ) {
+ protected ParColAggTask( MatrixBlock a, SideInput[] b, double[] scalars, int clen, int clen2, int outLen, int rl, int ru ) {
_a = a;
_b = b;
_scalars = scalars;
_clen = clen;
_clen2 = clen2;
+ _outLen = outLen;
_rl = rl;
_ru = ru;
}
@@ -364,7 +364,7 @@ public abstract class SpoofRowwise extends SpoofOperator
//allocate vector intermediates and partial output
if( _reqVectMem > 0 )
LibSpoofPrimitives.setupThreadLocalMemory(_reqVectMem, _clen, _clen2);
- double[] c = new double[(_clen2>0)?_clen*_clen2 : _clen];
+ double[] c = new double[_outLen];
if( _a instanceof CompressedMatrixBlock )
executeCompressed((CompressedMatrixBlock)_a, _b, _scalars, c, _clen, _rl, _ru);