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authorJakob Unterwurzacher2017-08-16 18:33:00 +0200
committerJakob Unterwurzacher2017-08-16 18:33:00 +0200
commit312ea32bb70abb93be315d0b7c442d5c4ae571d9 (patch)
tree31c7b91db06bf208a6d44dae0058171dd6735b80 /internal/cryptocore
parent838bf883df579a414289a3e05d238c582ac78523 (diff)
cryptocore: add urandom + randprefetch benchmarks
The benchmark that supported the decision for 512-byte prefetching previously lived outside the repo. Let's add it where it belongs so it cannot get lost.
Diffstat (limited to 'internal/cryptocore')
-rw-r--r--internal/cryptocore/randprefetch.go17
-rw-r--r--internal/cryptocore/randprefetch_test.go8
-rw-r--r--internal/cryptocore/randsize_test.go40
3 files changed, 51 insertions, 14 deletions
diff --git a/internal/cryptocore/randprefetch.go b/internal/cryptocore/randprefetch.go
index 081559d..0cde31d 100644
--- a/internal/cryptocore/randprefetch.go
+++ b/internal/cryptocore/randprefetch.go
@@ -6,20 +6,9 @@ import (
"sync"
)
-/*
-Number of bytes to prefetch.
-
-512 looks like a good compromise between throughput and latency:
-Benchmark16-2 3000000 567 ns/op 28.18 MB/s
-Benchmark64-2 5000000 293 ns/op 54.51 MB/s
-Benchmark128-2 10000000 220 ns/op 72.48 MB/s
-Benchmark256-2 10000000 210 ns/op 76.17 MB/s
-Benchmark512-2 10000000 191 ns/op 83.75 MB/s
-Benchmark1024-2 10000000 171 ns/op 93.48 MB/s
-Benchmark2048-2 10000000 165 ns/op 96.45 MB/s
-Benchmark4096-2 10000000 165 ns/op 96.58 MB/s
-Benchmark40960-2 10000000 147 ns/op 108.82 MB/s
-*/
+// Number of bytes to prefetch.
+// 512 looks like a good compromise between throughput and latency - see
+// randsize_test.go for numbers.
const prefetchN = 512
func init() {
diff --git a/internal/cryptocore/randprefetch_test.go b/internal/cryptocore/randprefetch_test.go
index 2a568f3..b263ef3 100644
--- a/internal/cryptocore/randprefetch_test.go
+++ b/internal/cryptocore/randprefetch_test.go
@@ -38,3 +38,11 @@ func TestRandPrefetch(t *testing.T) {
t.Errorf("random data should be incompressible, but: in=%d compressed=%d\n", p*l*l, b.Len())
}
}
+
+func BenchmarkRandPrefetch(b *testing.B) {
+ // 16-byte nonces are default since gocryptfs v0.7
+ b.SetBytes(16)
+ for i := 0; i < b.N; i++ {
+ randPrefetcher.read(16)
+ }
+}
diff --git a/internal/cryptocore/randsize_test.go b/internal/cryptocore/randsize_test.go
new file mode 100644
index 0000000..1db4745
--- /dev/null
+++ b/internal/cryptocore/randsize_test.go
@@ -0,0 +1,40 @@
+// +build go1.7
+
+// ^^^^^^^^^^^^ we use the "sub-benchmark" feature that was added in Go 1.7
+
+package cryptocore
+
+import (
+ "fmt"
+ "testing"
+)
+
+/*
+The troughput we get from /dev/urandom / getentropy depends a lot on the used
+block size. Results on my Pentium G630 running Linux 4.11:
+
+BenchmarkRandSize/16-2 3000000 571 ns/op 27.98 MB/s
+BenchmarkRandSize/32-2 3000000 585 ns/op 54.66 MB/s
+BenchmarkRandSize/64-2 2000000 860 ns/op 74.36 MB/s
+BenchmarkRandSize/128-2 1000000 1197 ns/op 106.90 MB/s
+BenchmarkRandSize/256-2 1000000 1867 ns/op 137.06 MB/s
+BenchmarkRandSize/512-2 500000 3187 ns/op 160.61 MB/s
+BenchmarkRandSize/1024-2 200000 5888 ns/op 173.91 MB/s
+BenchmarkRandSize/2048-2 100000 11554 ns/op 177.25 MB/s
+BenchmarkRandSize/4096-2 100000 22523 ns/op 181.86 MB/s
+BenchmarkRandSize/8192-2 30000 43111 ns/op 190.02 MB/s
+
+Results are similar when testing with dd, so this is not due to Go allocation
+overhead: dd if=/dev/urandom bs=16 count=100000 of=/dev/null
+*/
+func BenchmarkUrandomBlocksize(b *testing.B) {
+ for s := 16; s <= 8192; s *= 2 {
+ title := fmt.Sprintf("%d", s)
+ b.Run(title, func(b *testing.B) {
+ b.SetBytes(int64(s))
+ for i := 0; i < b.N; i++ {
+ RandBytes(s)
+ }
+ })
+ }
+}