From c6ba099428833a611059f7b15bf27201b5d588ce Mon Sep 17 00:00:00 2001
From: Hatsuyuki <hatsuyuki15@gmail.com>
Date: Thu, 15 Sep 2022 13:17:52 +0000
Subject: [PATCH] fix incorrect scaling behaviour with buffer capacity in some
 edge cases

---
 engine/planner.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/engine/planner.go b/engine/planner.go
index f71b10e6..06db743d 100644
--- a/engine/planner.go
+++ b/engine/planner.go
@@ -76,8 +76,8 @@ func (p *planner) Plan(ctx context.Context) error {
 
 	ctx = logger.WithContext(ctx, log)
 
-	free := max(capacity-running-p.buffer, 0)
-	diff := serverDiff(pending, free, p.cap)
+	free := max(capacity-running, 0)
+	diff := serverDiff(pending+p.buffer, free, p.cap)
 
 	// if the server differential to handle the build volume
 	// is positive, we can reduce server capacity.