From 428d7337e808ec5f4dba1b0aceda002f295cc320 Mon Sep 17 00:00:00 2001
From: Sebastiaan van Stijn <github@gone.nl>
Date: Tue, 12 Jul 2016 22:54:56 +0200
Subject: [PATCH] Don't set ulimits (nproc)

There is a not-insignificant performance overhead for all containers (if
containerd is a child of Docker, which is the current setup) if rlimits are
set on the main Docker daemon process (because the limits
propogate to all children).

We recommend using cgroups to do container-local accounting.

This applies the change added in 8db61095a3d0bcb0733580734ba5d54bc27a614d
to other init scripts.

Note that nfile cannot be set to unlimited, and the limit
is hardcoded to 1048576 (2^20) , see:
http://stackoverflow.com/a/1213069/1811501

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
---
 contrib/init/openrc/docker.initd    | 5 ++++-
 contrib/init/systemd/docker.service | 2 +-
 contrib/init/sysvinit-debian/docker | 7 +++++--
 contrib/init/upstart/docker.conf    | 6 +++++-
 4 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/contrib/init/openrc/docker.initd b/contrib/init/openrc/docker.initd
index f2e1536a96..5d3160338a 100644
--- a/contrib/init/openrc/docker.initd
+++ b/contrib/init/openrc/docker.initd
@@ -13,7 +13,10 @@ start_pre() {
 	checkpath -f -m 0644 -o root:docker "$DOCKER_LOGFILE"
 
 	ulimit -n 1048576
-	ulimit -u 1048576
+
+	# Having non-zero limits causes performance problems due to accounting overhead
+	# in the kernel. We recommend using cgroups to do container-local accounting.
+	ulimit -u unlimited
 
 	return 0
 }
diff --git a/contrib/init/systemd/docker.service b/contrib/init/systemd/docker.service
index c3f3472472..5024c96525 100644
--- a/contrib/init/systemd/docker.service
+++ b/contrib/init/systemd/docker.service
@@ -11,9 +11,9 @@ Type=notify
 # for containers run by docker
 ExecStart=/usr/bin/dockerd -H fd://
 ExecReload=/bin/kill -s HUP $MAINPID
+LimitNOFILE=1048576
 # Having non-zero Limit*s causes performance problems due to accounting overhead
 # in the kernel. We recommend using cgroups to do container-local accounting.
-LimitNOFILE=infinity
 LimitNPROC=infinity
 LimitCORE=infinity
 # Uncomment TasksMax if your systemd version supports it.
diff --git a/contrib/init/sysvinit-debian/docker b/contrib/init/sysvinit-debian/docker
index 047af417f3..034f9601e8 100755
--- a/contrib/init/sysvinit-debian/docker
+++ b/contrib/init/sysvinit-debian/docker
@@ -94,10 +94,13 @@ case "$1" in
 		chgrp docker "$DOCKER_LOGFILE"
 
 		ulimit -n 1048576
+
+		# Having non-zero limits causes performance problems due to accounting overhead
+		# in the kernel. We recommend using cgroups to do container-local accounting.
 		if [ "$BASH" ]; then
-			ulimit -u 1048576
+			ulimit -u unlimited
 		else
-			ulimit -p 1048576
+			ulimit -p unlimited
 		fi
 
 		log_begin_msg "Starting $DOCKER_DESC: $BASE"
diff --git a/contrib/init/upstart/docker.conf b/contrib/init/upstart/docker.conf
index b5ad74a6af..29a66de476 100644
--- a/contrib/init/upstart/docker.conf
+++ b/contrib/init/upstart/docker.conf
@@ -2,8 +2,12 @@ description "Docker daemon"
 
 start on (filesystem and net-device-up IFACE!=lo)
 stop on runlevel [!2345]
+
 limit nofile 524288 1048576
-limit nproc 524288 1048576
+
+# Having non-zero limits causes performance problems due to accounting overhead
+# in the kernel. We recommend using cgroups to do container-local accounting.
+limit nproc unlimited unlimited
 
 respawn