diff options
Diffstat (limited to 'synapse')
| -rw-r--r-- | synapse/config/server.py | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/synapse/config/server.py b/synapse/config/server.py index e33cd51f7c..89d61a0503 100644 --- a/synapse/config/server.py +++ b/synapse/config/server.py @@ -1,5 +1,6 @@ # -*- coding: utf-8 -*- # Copyright 2014-2016 OpenMarket Ltd +# Copyright 2017 New Vector Ltd # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. @@ -148,22 +149,24 @@ class ServerConfig(Config): # When running as a daemon, the file to store the pid in pid_file: %(pid_file)s - # CPU affinity mask. Setting this restricts the CPUs on which the process - # will be scheduled. It is represented as a bitmask, with the lowest order - # bit corresponding to the first logical CPU and the highest order bit - # corresponding to the last logical CPU. Not all CPUs may exist on a - # given system but a mask may specify more CPUs than are present. + # CPU affinity mask. Setting this restricts the CPUs on which the + # process will be scheduled. It is represented as a bitmask, with the + # lowest order bit corresponding to the first logical CPU and the + # highest order bit corresponding to the last logical CPU. Not all CPUs + # may exist on a given system but a mask may specify more CPUs than are + # present. # # For example: # 0x00000001 is processor #0, # 0x00000003 is processors #0 and #1, # 0xFFFFFFFF is all processors (#0 through #31). # - # This is desirable for Synapse processes (especially workers), which are - # inherently single-threaded due to the GIL and can suffer a 30-40% slowdown - # due to cache blow-out and thread context switching if the scheduler happens - # to schedule the underlying threads across different cores. - # See https://www.mirantis.com/blog/improve-performance-python-programs-restricting-single-cpu/ + # Pinning a Python process to a single CPU is desirable, because Python + # is inherently single-threaded due to the GIL, and can suffer a + # 30-40%% slowdown due to cache blow-out and thread context switching + # if the scheduler happens to schedule the underlying threads across + # different cores. See + # https://www.mirantis.com/blog/improve-performance-python-programs-restricting-single-cpu/. # # cpu_affinity: 0xFFFFFFFF |