diff --git a/changelog.d/5525.removal b/changelog.d/5525.removal
new file mode 100644
index 0000000000..af71560f36
--- /dev/null
+++ b/changelog.d/5525.removal
@@ -0,0 +1 @@
+Remove support for cpu_affinity setting.
diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml
index bd80d97a93..d5cc3e7abc 100644
--- a/docs/sample_config.yaml
+++ b/docs/sample_config.yaml
@@ -23,29 +23,6 @@ server_name: "SERVERNAME"
#
pid_file: DATADIR/homeserver.pid
-# 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).
-#
-# 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/.
-#
-# This setting requires the affinity package to be installed!
-#
-#cpu_affinity: 0xFFFFFFFF
-
# The path to the web client which will be served at /_matrix/client/
# if 'webclient' is configured under the 'listeners' configuration.
#
diff --git a/synapse/app/_base.py b/synapse/app/_base.py
index df4c2d4c97..d50a9840d4 100644
--- a/synapse/app/_base.py
+++ b/synapse/app/_base.py
@@ -19,7 +19,6 @@ import signal
import sys
import traceback
-import psutil
from daemonize import Daemonize
from twisted.internet import defer, error, reactor
@@ -68,21 +67,13 @@ def start_worker_reactor(appname, config):
gc_thresholds=config.gc_thresholds,
pid_file=config.worker_pid_file,
daemonize=config.worker_daemonize,
- cpu_affinity=config.worker_cpu_affinity,
print_pidfile=config.print_pidfile,
logger=logger,
)
def start_reactor(
- appname,
- soft_file_limit,
- gc_thresholds,
- pid_file,
- daemonize,
- cpu_affinity,
- print_pidfile,
- logger,
+ appname, soft_file_limit, gc_thresholds, pid_file, daemonize, print_pidfile, logger
):
""" Run the reactor in the main process
@@ -95,7 +86,6 @@ def start_reactor(
gc_thresholds:
pid_file (str): name of pid file to write to if daemonize is True
daemonize (bool): true to run the reactor in a background process
- cpu_affinity (int|None): cpu affinity mask
print_pidfile (bool): whether to print the pid file, if daemonize is True
logger (logging.Logger): logger instance to pass to Daemonize
"""
@@ -109,20 +99,6 @@ def start_reactor(
# between the sentinel and `run` logcontexts.
with PreserveLoggingContext():
logger.info("Running")
- if cpu_affinity is not None:
- # Turn the bitmask into bits, reverse it so we go from 0 up
- mask_to_bits = bin(cpu_affinity)[2:][::-1]
-
- cpus = []
- cpu_num = 0
-
- for i in mask_to_bits:
- if i == "1":
- cpus.append(cpu_num)
- cpu_num += 1
-
- p = psutil.Process()
- p.cpu_affinity(cpus)
change_resource_limit(soft_file_limit)
if gc_thresholds:
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index d19c7c7d71..49da105cf6 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -641,7 +641,6 @@ def run(hs):
gc_thresholds=hs.config.gc_thresholds,
pid_file=hs.config.pid_file,
daemonize=hs.config.daemonize,
- cpu_affinity=hs.config.cpu_affinity,
print_pidfile=hs.config.print_pidfile,
logger=logger,
)
diff --git a/synapse/config/server.py b/synapse/config/server.py
index 6d3f1da96c..9ceca0a606 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -57,7 +57,6 @@ class ServerConfig(Config):
self.user_agent_suffix = config.get("user_agent_suffix")
self.use_frozen_dicts = config.get("use_frozen_dicts", False)
self.public_baseurl = config.get("public_baseurl")
- self.cpu_affinity = config.get("cpu_affinity")
# Whether to send federation traffic out in this process. This only
# applies to some federation traffic, and so shouldn't be used to
@@ -336,29 +335,6 @@ class ServerConfig(Config):
#
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.
- #
- # For example:
- # 0x00000001 is processor #0,
- # 0x00000003 is processors #0 and #1,
- # 0xFFFFFFFF is all processors (#0 through #31).
- #
- # 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/.
- #
- # This setting requires the affinity package to be installed!
- #
- #cpu_affinity: 0xFFFFFFFF
-
# The path to the web client which will be served at /_matrix/client/
# if 'webclient' is configured under the 'listeners' configuration.
#
diff --git a/synapse/config/workers.py b/synapse/config/workers.py
index 75993abf35..4f283a0c2f 100644
--- a/synapse/config/workers.py
+++ b/synapse/config/workers.py
@@ -46,7 +46,6 @@ class WorkerConfig(Config):
self.worker_name = config.get("worker_name", self.worker_app)
self.worker_main_http_uri = config.get("worker_main_http_uri", None)
- self.worker_cpu_affinity = config.get("worker_cpu_affinity")
# This option is really only here to support `--manhole` command line
# argument.
|
