pkg/fuzzer: remove signal rotation

Signal rotation is intended to make the fuzzer re-discover flaky coverage
in non flaky way. However, taking into accout that we get effectively
the same effect after each manager restart, and that the fuzzer is overloaded
with triage/smash jobs, it does not look to be worth it.

2 files changed, 0 insertions, 33 deletions

diff --git a/pkg/signal/signal.go b/pkg/signal/signal.go
index 3eb4263de..ca73578fa 100644
--- a/pkg/signal/signal.go
+++ b/pkg/signal/signal.go
@@ -4,8 +4,6 @@
 // Package signal provides types for working with feedback signal.
 package signal
 
-import "math/rand"
-
 type (
 	elemType uint64
 	prioType int8
@@ -142,23 +140,6 @@ func (s *Signal) Subtract(s1 Signal) {
 	}
 }
 
-func (s Signal) RandomSubset(r *rand.Rand, size int) Signal {
-	if size > len(s) {
-		size = len(s)
-	}
-	keys := make([]elemType, 0, len(s))
-	for e := range s {
-		keys = append(keys, e)
-	}
-	r.Shuffle(len(keys), func(i, j int) { keys[i], keys[j] = keys[j], keys[i] })
-
-	ret := make(Signal, size)
-	for _, e := range keys[:size] {
-		ret[e] = s[e]
-	}
-	return ret
-}
-
 // FilterRaw returns a subset of original raw elements that either are not present in ignore,
 // or coincides with the one in alwaysTake.
 func FilterRaw(raw []uint64, ignore, alwaysTake Signal) []uint64 {
diff --git a/pkg/signal/signal_test.go b/pkg/signal/signal_test.go
index 52b91fc19..2610fe792 100644
--- a/pkg/signal/signal_test.go
+++ b/pkg/signal/signal_test.go
@@ -4,25 +4,11 @@
 package signal
 
 import (
-	"math/rand"
 	"testing"
 
-	"github.com/google/syzkaller/pkg/testutil"
 	"github.com/stretchr/testify/assert"
 )
 
-func TestRandomSubset(t *testing.T) {
-	r := rand.New(testutil.RandSource(t))
-	base := FromRaw([]uint64{0, 1, 2, 3, 4}, 0)
-	var s Signal
-	for i := 0; i < 1000 && s.Len() < base.Len(); i++ {
-		delta := base.RandomSubset(r, 1)
-		assert.Equal(t, 1, delta.Len())
-		s.Merge(delta)
-	}
-	assert.Equal(t, base.Len(), s.Len())
-}
-
 func TestSubtract(t *testing.T) {
 	base := FromRaw([]uint64{0, 1, 2, 3, 4}, 0)
 	assert.Equal(t, 5, base.Len())