From 6f6c23482be2f57fc1011187403b4aa5cdfc1a14 Mon Sep 17 00:00:00 2001
From: Christian Haudum <christian.haudum@gmail.com>
Date: Mon, 24 Jun 2024 10:17:02 +0200
Subject: [PATCH] perf(blooms): Replace sync.Mutex with sync.Once

Signed-off-by: Christian Haudum <christian.haudum@gmail.com>
---
 pkg/util/mempool/pool.go      | 8 ++------
 pkg/util/mempool/pool_test.go | 1 -
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/pkg/util/mempool/pool.go b/pkg/util/mempool/pool.go
index 3d1a89ba2813a..4ac5b96062c05 100644
--- a/pkg/util/mempool/pool.go
+++ b/pkg/util/mempool/pool.go
@@ -20,7 +20,7 @@ var (
 type slab struct {
 	buffer      chan unsafe.Pointer
 	size, count int
-	mtx         sync.Mutex
+	once        sync.Once
 	metrics     *metrics
 	name        string
 }
@@ -49,11 +49,7 @@ func (s *slab) init() {
 
 func (s *slab) get(size int) ([]byte, error) {
 	s.metrics.accesses.WithLabelValues(s.name, opTypeGet).Inc()
-	s.mtx.Lock()
-	if s.buffer == nil {
-		s.init()
-	}
-	defer s.mtx.Unlock()
+	s.once.Do(s.init)
 
 	// wait for available buffer on channel
 	var buf []byte
diff --git a/pkg/util/mempool/pool_test.go b/pkg/util/mempool/pool_test.go
index c5de6e8ae0df1..289479078df66 100644
--- a/pkg/util/mempool/pool_test.go
+++ b/pkg/util/mempool/pool_test.go
@@ -124,7 +124,6 @@ func BenchmarkSlab(b *testing.B) {
 	} {
 		b.Run(flagext.ByteSize(uint64(sz)).String(), func(b *testing.B) {
 			slab := newSlab(sz, 1, newMetrics(nil, "test"))
-			slab.init()
 			b.ResetTimer()
 
 			for i := 0; i < b.N; i++ {