Drop support for cpu_affinity (#5525)

This has no useful purpose on python3, and is generally a source of confusion.
This commit is contained in:
Richard van der Hoff 2019-06-22 02:01:55 +01:00 committed by Amber Brown
parent e1a795758c
commit 6cda36777b
6 changed files with 2 additions and 74 deletions

1
changelog.d/5525.removal Normal file
View file

@ -0,0 +1 @@
Remove support for cpu_affinity setting.

View file

@ -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.
#

View file

@ -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:

View file

@ -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,
)

View file

@ -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.
#

View file

@ -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.