Fix histogram memory issues.
Before we had buckets of 5 micro second size. For a 100 MS GC
this used at least 16 * (100 / .005) bytes of storage inside of the
histogram data structure. If you consider the 3 different GC types,
and each timing logger having its own histogram its easy to see
how memory used was significant.
We now have an upper bound on the number of buckets (default 100).
When we hit the upper bound we simply combine adjacent buckets
together. This reduces the total number of buckets by a factor of
2, while increasing the bucket size by a factor of 2. This means
that we may lose a slight amount of precision, but the confidence
intervals remain nearly as useful.
Total unknown memory (occam-svelte):
Before: 45648 kB:
After: 33304 kB
There are probably still some additional optimizations which can be
done as disabling histograms altogether reduces the memory used by
another ~2mB.
A bit of other cleanup in image_space.cc and dlmalloc_space.cc.
Bug: 9967927
Change-Id: I87bb6fe4a3e0e790f104abf3cf07f67677cd7ab3
diff --git a/runtime/base/histogram_test.cc b/runtime/base/histogram_test.cc
index 218c022..534440c 100644
--- a/runtime/base/histogram_test.cc
+++ b/runtime/base/histogram_test.cc
@@ -23,7 +23,7 @@
namespace art {
// Simple usage:
-// Histogram *hist = new Histogram("SimplePercentiles");
+// Histogram *hist(new Histogram("SimplePercentiles"));
// Percentile PerValue
// hist->AddValue(121);
// hist->AddValue(132);
@@ -34,7 +34,7 @@
// PerValue = hist->PercentileVal(0.50); finds the 50th percentile(median).
TEST(Histtest, MeanTest) {
- UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("MeanTest"));
+ UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("MeanTest", 5));
double mean;
for (size_t Idx = 0; Idx < 90; Idx++) {
@@ -52,20 +52,20 @@
}
TEST(Histtest, VarianceTest) {
- UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("VarianceTest"));
+ UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("VarianceTest", 5));
double variance;
hist->AddValue(9);
hist->AddValue(17);
hist->AddValue(28);
hist->AddValue(28);
- hist->CreateHistogram();
variance = hist->Variance();
EXPECT_EQ(64.25, variance);
}
TEST(Histtest, Percentile) {
- UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("Percentile"));
+ UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("Percentile", 5));
+ Histogram<uint64_t>::CumulativeData data;
double PerValue;
@@ -85,13 +85,14 @@
hist->AddValue(145);
hist->AddValue(155);
- hist->CreateHistogram();
- PerValue = hist->Percentile(0.50);
+ hist->CreateHistogram(data);
+ PerValue = hist->Percentile(0.50, data);
EXPECT_EQ(875, static_cast<int>(PerValue * 10));
}
TEST(Histtest, UpdateRange) {
- UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("UpdateRange"));
+ UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("UpdateRange", 5));
+ Histogram<uint64_t>::CumulativeData data;
double PerValue;
@@ -116,14 +117,13 @@
hist->AddValue(200);
hist->AddValue(205);
hist->AddValue(212);
- hist->CreateHistogram();
- PerValue = hist->Percentile(0.50);
+ hist->CreateHistogram(data);
+ PerValue = hist->Percentile(0.50, data);
std::string text;
std::stringstream stream;
- std::string expected =
- "UpdateRange:\t99% C.I. 15us-212us Avg: 126.380us Max: 212us\n";
- hist->PrintConfidenceIntervals(stream, 0.99);
+ std::string expected("UpdateRange:\t99% C.I. 15us-212us Avg: 126.380us Max: 212us\n");
+ hist->PrintConfidenceIntervals(stream, 0.99, data);
EXPECT_EQ(expected, stream.str());
EXPECT_GE(PerValue, 132);
@@ -131,7 +131,8 @@
}
TEST(Histtest, Reset) {
- UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("Reset"));
+ UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("Reset", 5));
+ Histogram<uint64_t>::CumulativeData data;
double PerValue;
hist->AddValue(0);
@@ -159,14 +160,13 @@
hist->AddValue(200);
hist->AddValue(205);
hist->AddValue(212);
- hist->CreateHistogram();
- PerValue = hist->Percentile(0.50);
+ hist->CreateHistogram(data);
+ PerValue = hist->Percentile(0.50, data);
std::string text;
std::stringstream stream;
- std::string expected =
- "Reset:\t99% C.I. 15us-212us Avg: 126.380us Max: 212us\n";
- hist->PrintConfidenceIntervals(stream, 0.99);
+ std::string expected("Reset:\t99% C.I. 15us-212us Avg: 126.380us Max: 212us\n");
+ hist->PrintConfidenceIntervals(stream, 0.99, data);
EXPECT_EQ(expected, stream.str());
EXPECT_GE(PerValue, 132);
@@ -174,7 +174,8 @@
}
TEST(Histtest, MultipleCreateHist) {
- UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("MultipleCreateHist"));
+ UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("MultipleCreateHist", 5));
+ Histogram<uint64_t>::CumulativeData data;
double PerValue;
hist->AddValue(15);
@@ -184,7 +185,7 @@
hist->AddValue(68);
hist->AddValue(75);
hist->AddValue(93);
- hist->CreateHistogram();
+ hist->CreateHistogram(data);
hist->AddValue(110);
hist->AddValue(121);
hist->AddValue(132);
@@ -193,19 +194,18 @@
hist->AddValue(155);
hist->AddValue(163);
hist->AddValue(168);
- hist->CreateHistogram();
+ hist->CreateHistogram(data);
hist->AddValue(175);
hist->AddValue(182);
hist->AddValue(193);
hist->AddValue(200);
hist->AddValue(205);
hist->AddValue(212);
- hist->CreateHistogram();
- PerValue = hist->Percentile(0.50);
+ hist->CreateHistogram(data);
+ PerValue = hist->Percentile(0.50, data);
std::stringstream stream;
- std::string expected =
- "MultipleCreateHist:\t99% C.I. 15us-212us Avg: 126.380us Max: 212us\n";
- hist->PrintConfidenceIntervals(stream, 0.99);
+ std::string expected("MultipleCreateHist:\t99% C.I. 15us-212us Avg: 126.380us Max: 212us\n");
+ hist->PrintConfidenceIntervals(stream, 0.99, data);
EXPECT_EQ(expected, stream.str());
EXPECT_GE(PerValue, 132);
@@ -213,18 +213,20 @@
}
TEST(Histtest, SingleValue) {
- UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("SingleValue"));
+ UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("SingleValue", 5));
+ Histogram<uint64_t>::CumulativeData data;
hist->AddValue(1);
- hist->CreateHistogram();
+ hist->CreateHistogram(data);
std::stringstream stream;
std::string expected = "SingleValue:\t99% C.I. 1us-1us Avg: 1us Max: 1us\n";
- hist->PrintConfidenceIntervals(stream, 0.99);
+ hist->PrintConfidenceIntervals(stream, 0.99, data);
EXPECT_EQ(expected, stream.str());
}
TEST(Histtest, CappingPercentiles) {
- UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("CappingPercentiles"));
+ UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("CappingPercentiles", 5));
+ Histogram<uint64_t>::CumulativeData data;
double per_995;
double per_005;
@@ -232,8 +234,8 @@
for (uint64_t idx = 0ull; idx < 150ull; idx++) {
hist->AddValue(0);
}
- hist->CreateHistogram();
- per_995 = hist->Percentile(0.995);
+ hist->CreateHistogram(data);
+ per_995 = hist->Percentile(0.995, data);
EXPECT_EQ(per_995, 0);
hist->Reset();
for (size_t idx = 0; idx < 200; idx++) {
@@ -241,15 +243,16 @@
hist->AddValue(val);
}
}
- hist->CreateHistogram();
- per_005 = hist->Percentile(0.005);
- per_995 = hist->Percentile(0.995);
+ hist->CreateHistogram(data);
+ per_005 = hist->Percentile(0.005, data);
+ per_995 = hist->Percentile(0.995, data);
EXPECT_EQ(1, per_005);
EXPECT_EQ(4, per_995);
}
TEST(Histtest, SpikyValues) {
- UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("SpikyValues"));
+ UniquePtr<Histogram<uint64_t> > hist(new Histogram<uint64_t>("SpikyValues", 5, 4096));
+ Histogram<uint64_t>::CumulativeData data;
for (uint64_t idx = 0ull; idx < 30ull; idx++) {
for (uint64_t idx_inner = 0ull; idx_inner < 5ull; idx_inner++) {
@@ -257,11 +260,10 @@
}
}
hist->AddValue(10000);
- hist->CreateHistogram();
+ hist->CreateHistogram(data);
std::stringstream stream;
- std::string expected =
- "SpikyValues:\t99% C.I. 0.089us-2541.825us Avg: 95.033us Max: 10000us\n";
- hist->PrintConfidenceIntervals(stream, 0.99);
+ std::string expected = "SpikyValues:\t99% C.I. 0.089us-2541.825us Avg: 95.033us Max: 10000us\n";
+ hist->PrintConfidenceIntervals(stream, 0.99, data);
EXPECT_EQ(expected, stream.str());
}