From 5dd40973f75506b2f2b51d18c81b239654b44294 Mon Sep 17 00:00:00 2001
From: Zachary Ware <zach@python.org>
Date: Fri, 14 Nov 2025 19:13:40 -0600
Subject: [PATCH 1/2] Use max_builds instead of a lock

---
 master/custom/workers.py | 10 +++++++---
 master/master.cfg        |  9 ---------
 2 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/master/custom/workers.py b/master/custom/workers.py
index bf960055..3199ddd3 100644
--- a/master/custom/workers.py
+++ b/master/custom/workers.py
@@ -55,9 +55,13 @@ def __init__(
         if settings.use_local_worker:
             self.bb_worker = _worker.LocalWorker(name)
         else:
-            self.bb_worker = _worker.Worker(name, str(pw),
-                                            notify_on_missing=emails,
-                                            keepalive_interval=KEEPALIVE)
+            self.bb_worker = _worker.Worker(
+                name,
+                str(pw),
+                notify_on_missing=emails,
+                keepalive_interval=KEEPALIVE,
+                max_builds=parallel_builders or 1,
+            )
 
 # Some of Itamar's workers are reprovisioned every Wednesday at 9am PT.
 # Builds scheduled between 8am - 10am PT on Wednesdays will be delayed to
diff --git a/master/master.cfg b/master/master.cfg
index 5acf952f..8b9de3d6 100644
--- a/master/master.cfg
+++ b/master/master.cfg
@@ -149,14 +149,6 @@ GIT_KWDS = {
 c["builders"] = []
 c["schedulers"] = []
 
-# The following with the worker owners' agreement
-cpulock = locks.WorkerLock(
-    "cpu",
-    maxCountForWorker={
-        w.name: w.parallel_builders for w in WORKERS if w.parallel_builders
-    },
-)
-
 
 def is_important_file(filename):
     unimportant_prefixes = (
@@ -274,7 +266,6 @@ for branch in BRANCHES:
             builddir=f"{branch.builddir_name}.{worker.name}{f.buildersuffix}",
             factory=f,
             tags=tags,
-            locks=[cpulock.access("counting")],
         )
 
         if worker.downtime:

From 83a36880be1e8cf7bb47a8c0c82437a879e8e4d5 Mon Sep 17 00:00:00 2001
From: Petr Viktorin <encukou@gmail.com>
Date: Thu, 4 Jun 2026 14:42:46 +0200
Subject: [PATCH 2/2] Simplify

---
 master/custom/workers.py | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/master/custom/workers.py b/master/custom/workers.py
index 3199ddd3..cdc4d151 100644
--- a/master/custom/workers.py
+++ b/master/custom/workers.py
@@ -30,7 +30,7 @@ def __init__(
         tags=None,
         branches=None,
         not_branches=None,
-        parallel_builders=None,
+        parallel_builders=1,
         parallel_tests=None,
         timeout_factor=1,
         exclude_test_resources=None,
@@ -40,7 +40,6 @@ def __init__(
         self.tags = tags or set()
         self.branches = branches
         self.not_branches = not_branches
-        self.parallel_builders = parallel_builders
         self.parallel_tests = parallel_tests
         self.timeout_factor = timeout_factor
         self.exclude_test_resources = exclude_test_resources or []
@@ -60,7 +59,7 @@ def __init__(
                 str(pw),
                 notify_on_missing=emails,
                 keepalive_interval=KEEPALIVE,
-                max_builds=parallel_builders or 1,
+                max_builds=parallel_builders,
             )
 
 # Some of Itamar's workers are reprovisioned every Wednesday at 9am PT.