chromeos-base/chromeos-base/files/sysctl.conf

# /etc/sysctl.conf
#
# For more information on how this file works, please see
# the manpages sysctl(8) and sysctl.conf(5).
#
# In order for this file to work properly, you must first
# enable 'Sysctl support' in the kernel.
#
# Look in /proc/sys/ for all the things you can setup.
#

#
# Original Gentoo settings:
#

# Disables packet forwarding
net.ipv4.ip_forward = 0
# Disables IP dynaddr
#net.ipv4.ip_dynaddr = 0
# Disable ECN
#net.ipv4.tcp_ecn = 0
# Enables source route verification
net.ipv4.conf.default.rp_filter = 1
# Enable reverse path
net.ipv4.conf.all.rp_filter = 1

# Enable SYN cookies (yum!)
# http://cr.yp.to/syncookies.html
#net.ipv4.tcp_syncookies = 1

# Disable source route
#net.ipv4.conf.all.accept_source_route = 0
#net.ipv4.conf.default.accept_source_route = 0

# Disable redirects
#net.ipv4.conf.all.accept_redirects = 0
#net.ipv4.conf.default.accept_redirects = 0

# Disable secure redirects
#net.ipv4.conf.all.secure_redirects = 0
#net.ipv4.conf.default.secure_redirects = 0

# Ignore ICMP broadcasts
#net.ipv4.icmp_echo_ignore_broadcasts = 1

# Perform PLPMTUD only after detecting a "blackhole" in old-style PMTUD
net.ipv4.tcp_mtu_probing = 1

# Disables the magic-sysrq key
#kernel.sysrq = 0
# When the kernel panics, automatically reboot in 3 seconds
#kernel.panic = 3
# Allow for more PIDs (cool factor!); may break some programs
#kernel.pid_max = 999999

# You should compile nfsd into the kernel or add it
# to modules.autoload for this to work properly
# TCP Port for lock manager
#fs.nfs.nlm_tcpport = 0
# UDP Port for lock manager
#fs.nfs.nlm_udpport = 0

#
# ChromeOS specific settings:
#

# Set watchdog_thresh
kernel.watchdog_thresh = 5
# When the kernel panics, automatically reboot to preserve dump in ram
kernel.panic = -1
# Reboot on oops as well
kernel.panic_on_oops = 1

# Disable shrinking the cwnd when connection is idle
net.ipv4.tcp_slow_start_after_idle = 0

# Protect working set in order to avoid thrashing.
# See http://crosbug.com/7561 for details.
vm.min_filelist_kbytes = 50000

# Allow full memory overcommit as we rather close or kill tabs than
# refuse memory to arbitrary core processes.
vm.overcommit_memory = 1

# Use laptop mode settings always
vm.dirty_background_ratio = 1
vm.dirty_expire_centisecs = 60000
vm.dirty_ratio = 60
vm.dirty_writeback_centisecs = 60000
vm.laptop_mode = 0

# Disable kernel address visibility to non-root users.
kernel.kptr_restrict = 1

# Increase shared memory segment limit for plugins rendering large areas
kernel.shmmax = 134217728