From e4ccddf5b7f31b04bee6847e54f2bdbeef58fcee Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Tue, 14 Jun 2022 15:20:17 +0100
Subject: [PATCH] Estimate cost for metrics better

---
 internal/caching/impl_ristretto.go | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/internal/caching/impl_ristretto.go b/internal/caching/impl_ristretto.go
index 52452be70..cfbd0bdd7 100644
--- a/internal/caching/impl_ristretto.go
+++ b/internal/caching/impl_ristretto.go
@@ -35,8 +35,7 @@ func NewRistrettoCache(maxCost CacheSize, enablePrometheus bool) (*Caches, error
 		Subsystem: "caching_ristretto",
 		Name:      "cost",
 	}, func() float64 {
-		evicted := cache.Metrics.CostEvicted() + cache.Metrics.CostEvicted()
-		return float64(cache.Metrics.CostAdded() - evicted)
+		return float64(cache.Metrics.CostAdded() - cache.Metrics.CostEvicted())
 	})
 	return &Caches{
 		RoomVersions: &RistrettoCachePartition[string, gomatrixserverlib.RoomVersion]{