From 0f23a90d5081691dd276ef59ec24b05f23ef9a8d Mon Sep 17 00:00:00 2001
From: David Wilson <dw@botanicus.net>
Date: Sun, 4 Aug 2019 14:37:59 +0100
Subject: [PATCH] ansible: log affinity assignments

---
 ansible_mitogen/affinity.py | 27 +++++++++++++++++----------
 ansible_mitogen/process.py  |  6 +++---
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/ansible_mitogen/affinity.py b/ansible_mitogen/affinity.py
index eeeb4d38..9eb6597a 100644
--- a/ansible_mitogen/affinity.py
+++ b/ansible_mitogen/affinity.py
@@ -73,7 +73,9 @@ necessarily involves preventing the scheduler from making load balancing
 decisions.
 """
 
+from __future__ import absolute_import
 import ctypes
+import logging
 import mmap
 import multiprocessing
 import os
@@ -83,6 +85,9 @@ import mitogen.core
 import mitogen.parent
 
 
+LOG = logging.getLogger(__name__)
+
+
 try:
     _libc = ctypes.CDLL(None, use_errno=True)
     _strerror = _libc.strerror
@@ -207,11 +212,13 @@ class FixedPolicy(Policy):
             self._reserve_mask = 3
             self._reserve_shift = 2
 
-    def _set_affinity(self, mask):
+    def _set_affinity(self, descr, mask):
+        if descr:
+            LOG.debug('CPU mask for %s: %#08x', descr, mask)
         mitogen.parent._preexec_hook = self._clear
         self._set_cpu_mask(mask)
 
-    def _balance(self):
+    def _balance(self, descr):
         self.state.lock.acquire()
         try:
             n = self.state.counter
@@ -219,28 +226,28 @@ class FixedPolicy(Policy):
         finally:
             self.state.lock.release()
 
-        self._set_cpu(self._reserve_shift + (
+        self._set_cpu(descr, self._reserve_shift + (
             (n % (self.cpu_count - self._reserve_shift))
         ))
 
-    def _set_cpu(self, cpu):
-        self._set_affinity(1 << (cpu % self.cpu_count))
+    def _set_cpu(self, descr, cpu):
+        self._set_affinity(descr, 1 << (cpu % self.cpu_count))
 
     def _clear(self):
         all_cpus = (1 << self.cpu_count) - 1
-        self._set_affinity(all_cpus & ~self._reserve_mask)
+        self._set_affinity(None, all_cpus & ~self._reserve_mask)
 
     def assign_controller(self):
         if self._reserve_controller:
-            self._set_cpu(1)
+            self._set_cpu('Ansible top-level process', 1)
         else:
-            self._balance()
+            self._balance('Ansible top-level process')
 
     def assign_muxprocess(self, index):
-        self._set_cpu(index)
+        self._set_cpu('MuxProcess %d' % (index,), index)
 
     def assign_worker(self):
-        self._balance()
+        self._balance('WorkerProcess')
 
     def assign_subprocess(self):
         self._clear()
diff --git a/ansible_mitogen/process.py b/ansible_mitogen/process.py
index acf6cf36..7e74c36a 100644
--- a/ansible_mitogen/process.py
+++ b/ansible_mitogen/process.py
@@ -275,13 +275,13 @@ def common_setup(enable_affinity=True, _init_logging=True):
     save_pid('controller')
     ansible_mitogen.logging.set_process_name('top')
 
+    if _init_logging:
+        ansible_mitogen.logging.setup()
+
     if enable_affinity:
         ansible_mitogen.affinity.policy.assign_controller()
 
     mitogen.utils.setup_gil()
-    if _init_logging:
-        ansible_mitogen.logging.setup()
-
     if faulthandler is not None:
         faulthandler.enable()