Make psutil an explicit dependency

As of #4027, we require psutil to be installed, so it should be in our
dependency list. We can also remove some of the conditional import code
introduced by #992.

Fixes #4062.

1 files changed, 4 insertions, 7 deletions

diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py

index e3f0d99a3f..a0c0fc78ec 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -20,6 +20,7 @@ import sys
 
 from six import iteritems
 
+import psutil
 from prometheus_client import Gauge
 
 from twisted.application import service
@@ -502,7 +503,6 @@ def run(hs):
 
     def performance_stats_init():
         try:
-            import psutil
             process = psutil.Process()
             # Ensure we can fetch both, and make the initial request for cpu_percent
             # so the next request will use this as the initial point.
@@ -510,12 +510,9 @@ def run(hs):
             process.cpu_percent(interval=None)
             logger.info("report_stats can use psutil")
             stats_process.append(process)
-        except (ImportError, AttributeError):
-            logger.warn(
-                "report_stats enabled but psutil is not installed or incorrect version."
-                " Disabling reporting of memory/cpu stats."
-                " Ensuring psutil is available will help matrix.org track performance"
-                " changes across releases."
+        except (AttributeError):
+            logger.warning(
+                "Unable to read memory/cpu stats. Disabling reporting."
             )
 
     def generate_user_daily_visit_stats():