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Posted to commits@spark.apache.org by da...@apache.org on 2016/02/09 22:06:41 UTC
spark git commit: [SPARK-12888] [SQL] [FOLLOW-UP] benchmark the new
hash expression
Repository: spark
Updated Branches:
refs/heads/master 2dbb91644 -> 7fe4fe630
[SPARK-12888] [SQL] [FOLLOW-UP] benchmark the new hash expression
Adds the benchmark results as comments.
The codegen version is slower than the interpreted version for `simple` case becasue of 3 reasons:
1. codegen version use a more complex hash algorithm than interpreted version, i.e. `Murmur3_x86_32.hashInt` vs [simple multiplication and addition](https://github.com/apache/spark/blob/master/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/rows.scala#L153).
2. codegen version will write the hash value to a row first and then read it out. I tried to create a `GenerateHasher` that can generate code to return hash value directly and got about 60% speed up for the `simple` case, does it worth?
3. the row in `simple` case only has one int field, so the runtime reflection may be removed because of branch prediction, which makes the interpreted version faster.
The `array` case is also slow for similar reasons, e.g. array elements are of same type, so interpreted version can probably get rid of runtime reflection by branch prediction.
Author: Wenchen Fan <we...@databricks.com>
Closes #10917 from cloud-fan/hash-benchmark.
Project: http://git-wip-us.apache.org/repos/asf/spark/repo
Commit: http://git-wip-us.apache.org/repos/asf/spark/commit/7fe4fe63
Tree: http://git-wip-us.apache.org/repos/asf/spark/tree/7fe4fe63
Diff: http://git-wip-us.apache.org/repos/asf/spark/diff/7fe4fe63
Branch: refs/heads/master
Commit: 7fe4fe630a3fc9755ebd0325bb595d76381633e8
Parents: 2dbb916
Author: Wenchen Fan <we...@databricks.com>
Authored: Tue Feb 9 13:06:36 2016 -0800
Committer: Davies Liu <da...@gmail.com>
Committed: Tue Feb 9 13:06:36 2016 -0800
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.../scala/org/apache/spark/util/Benchmark.scala | 4 +-
.../org/apache/spark/sql/HashBenchmark.scala | 40 ++++++++++++++++----
2 files changed, 35 insertions(+), 9 deletions(-)
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http://git-wip-us.apache.org/repos/asf/spark/blob/7fe4fe63/core/src/main/scala/org/apache/spark/util/Benchmark.scala
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diff --git a/core/src/main/scala/org/apache/spark/util/Benchmark.scala b/core/src/main/scala/org/apache/spark/util/Benchmark.scala
index 1bf6f82..39d1829 100644
--- a/core/src/main/scala/org/apache/spark/util/Benchmark.scala
+++ b/core/src/main/scala/org/apache/spark/util/Benchmark.scala
@@ -35,7 +35,8 @@ import org.apache.commons.lang3.SystemUtils
* If outputPerIteration is true, the timing for each run will be printed to stdout.
*/
private[spark] class Benchmark(
- name: String, valuesPerIteration: Long,
+ name: String,
+ valuesPerIteration: Long,
iters: Int = 5,
outputPerIteration: Boolean = false) {
val benchmarks = mutable.ArrayBuffer.empty[Benchmark.Case]
@@ -61,7 +62,6 @@ private[spark] class Benchmark(
println
val firstBest = results.head.bestMs
- val firstAvg = results.head.avgMs
// The results are going to be processor specific so it is useful to include that.
println(Benchmark.getProcessorName())
printf("%-35s %16s %12s %13s %10s\n", name + ":", "Best/Avg Time(ms)", "Rate(M/s)",
http://git-wip-us.apache.org/repos/asf/spark/blob/7fe4fe63/sql/catalyst/src/test/scala/org/apache/spark/sql/HashBenchmark.scala
----------------------------------------------------------------------
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/HashBenchmark.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/HashBenchmark.scala
index 184f845..5a929f2 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/HashBenchmark.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/HashBenchmark.scala
@@ -29,9 +29,7 @@ import org.apache.spark.util.Benchmark
*/
object HashBenchmark {
- def test(name: String, schema: StructType, iters: Int): Unit = {
- val numRows = 1024 * 8
-
+ def test(name: String, schema: StructType, numRows: Int, iters: Int): Unit = {
val generator = RandomDataGenerator.forType(schema, nullable = false).get
val encoder = RowEncoder(schema)
val attrs = schema.toAttributes
@@ -70,7 +68,14 @@ object HashBenchmark {
def main(args: Array[String]): Unit = {
val simple = new StructType().add("i", IntegerType)
- test("simple", simple, 1024)
+ /*
+ Intel(R) Core(TM) i7-4960HQ CPU @ 2.60GHz
+ Hash For simple: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
+ -------------------------------------------------------------------------------------------
+ interpreted version 941 / 955 142.6 7.0 1.0X
+ codegen version 1737 / 1775 77.3 12.9 0.5X
+ */
+ test("simple", simple, 1 << 13, 1 << 14)
val normal = new StructType()
.add("null", NullType)
@@ -87,18 +92,39 @@ object HashBenchmark {
.add("binary", BinaryType)
.add("date", DateType)
.add("timestamp", TimestampType)
- test("normal", normal, 128)
+ /*
+ Intel(R) Core(TM) i7-4960HQ CPU @ 2.60GHz
+ Hash For normal: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
+ -------------------------------------------------------------------------------------------
+ interpreted version 2209 / 2271 0.9 1053.4 1.0X
+ codegen version 1887 / 2018 1.1 899.9 1.2X
+ */
+ test("normal", normal, 1 << 10, 1 << 11)
val arrayOfInt = ArrayType(IntegerType)
val array = new StructType()
.add("array", arrayOfInt)
.add("arrayOfArray", ArrayType(arrayOfInt))
- test("array", array, 64)
+ /*
+ Intel(R) Core(TM) i7-4960HQ CPU @ 2.60GHz
+ Hash For array: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
+ -------------------------------------------------------------------------------------------
+ interpreted version 1481 / 1529 0.1 11301.7 1.0X
+ codegen version 2591 / 2636 0.1 19771.1 0.6X
+ */
+ test("array", array, 1 << 8, 1 << 9)
val mapOfInt = MapType(IntegerType, IntegerType)
val map = new StructType()
.add("map", mapOfInt)
.add("mapOfMap", MapType(IntegerType, mapOfInt))
- test("map", map, 64)
+ /*
+ Intel(R) Core(TM) i7-4960HQ CPU @ 2.60GHz
+ Hash For map: Best/Avg Time(ms) Rate(M/s) Per Row(ns) Relative
+ -------------------------------------------------------------------------------------------
+ interpreted version 1820 / 1861 0.0 444347.2 1.0X
+ codegen version 205 / 223 0.0 49936.5 8.9X
+ */
+ test("map", map, 1 << 6, 1 << 6)
}
}
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