Eric Dumazet 79134e6ce2 net: do not create fallback tunnels for non-default namespaces ... fallback tunnels (like tunl0, gre0, gretap0, erspan0, sit0, ip6tnl0, ip6gre0) are automatically created when the corresponding module is loaded. These tunnels are also automatically created when a new network namespace is created, at a great cost. In many cases, netns are used for isolation purposes, and these extra network devices are a waste of resources. We are using thousands of netns per host, and hit the netns creation/delete bottleneck a lot. (Many thanks to Kirill for recent work on this) Add a new sysctl so that we can opt-out from this automatic creation. Note that these tunnels are still created for the initial namespace, to be the least intrusive for typical setups. Tested: lpk43:~# cat add_del_unshare.sh for i in `seq 1 40` do (for j in `seq 1 100` ; do unshare -n /bin/true >/dev/null ; done) & done wait lpk43:~# echo 0 >/proc/sys/net/core/fb_tunnels_only_for_init_net lpk43:~# time ./add_del_unshare.sh real 0m37.521s user 0m0.886s sys 7m7.084s lpk43:~# echo 1 >/proc/sys/net/core/fb_tunnels_only_for_init_net lpk43:~# time ./add_del_unshare.sh real 0m4.761s user 0m0.851s sys 1m8.343s lpk43:~# Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>		2018-03-09 11:23:11 -05:00
..
ABI	ACPI updates for v4.16-rc2	2018-02-15 14:50:32 -08:00
accelerators	ocxl: Documentation	2018-01-27 20:02:24 +11:00
accounting
acpi	ACPI / LPIT: Add Low Power Idle Table (LPIT) support	2017-10-11 15:38:10 +02:00
admin-guide	More ACPI updates for v4.16-rc1	2018-02-09 09:44:25 -08:00
aoe
arm	ARM: sunxi: add support for R40 SoC	2017-09-22 21:57:09 +02:00
arm64	arm64 updates for 4.16:	2018-01-30 13:57:43 -08:00
auxdisplay
backlight
blackfin
block	block, bfq: move debug blkio stats behind CONFIG_DEBUG_BLK_CGROUP	2017-11-14 20:13:33 -07:00
blockdev	SCSI misc on 20170907	2017-09-07 21:11:05 -07:00
bpf	bpf: add documentation to compare clang "-target bpf" and default target	2018-02-02 11:14:19 +01:00
bus-devices
cdrom	documentation: Update ide-cd documentation to reflect CONFIG_BLK_DEV_HD_IDE removal	2017-10-12 11:25:31 -06:00
cgroup-v1	Documentation: Fix 'file_mapped' -> 'mapped_file'	2018-01-30 09:52:11 -08:00
cma
connector
console
core-api	idr: Add documentation	2018-02-06 16:41:29 -05:00
cpu-freq	cpufreq: Add and use cpufreq_for_each_{valid_,}entry_idx()	2018-02-08 10:21:39 +01:00
cpuidle
cris
crypto	crypto: doc - adapt api sample to use async. op wait	2017-11-03 22:11:23 +08:00
dev-tools	Kbuild misc updates for v4.15	2017-11-17 17:51:33 -08:00
device-mapper	dm cache: Documentation: update default migration_throttling value	2018-01-30 16:55:47 -05:00
devicetree	dt-bindings: net: dsa: marvell: describe compatibility string	2018-03-07 12:18:50 -05:00
doc-guide	scripts: kernel-doc: parse next structs/unions	2017-12-21 13:41:46 -07:00
driver-api	s390/docs: reword airq section	2018-02-02 10:47:15 +01:00
driver-model	serdev: Introduce devm_serdev_device_open()	2018-01-08 10:08:34 +00:00
early-userspace
EDID
extcon
fault-injection	Documentation updates for 4.16. New stuff includes refcount_t	2018-01-31 19:25:25 -08:00
fb	documentation: fb: update list of available compiled-in fonts	2017-11-08 03:39:52 -07:00
features	membarrier-sync-core: Document architecture support	2018-02-10 12:45:10 +01:00
filesystems	afs: Support the AFS dynamic root	2018-02-06 14:43:37 +00:00
firmware_class
fmc
fpga	fpga: mgr: separate getting/locking FPGA manager	2017-11-28 16:30:37 +01:00
frv
gpio	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2018-02-01 10:49:58 -08:00
gpu	Fixes for 4.16. I contains fixes for deadlock on runtime suspend on few	2018-02-22 08:39:26 +10:00
hid	Documentation: fix input related doc refs	2017-10-12 11:14:06 -06:00
hwmon	hwmon: (pmbus/max31785) Add dual tachometer support	2018-01-02 15:05:34 -08:00
i2c	i2c: i801: Add missing documentation entries for Braswell and Kaby Lake	2018-02-21 09:17:20 +01:00
ia64	ia64: doc: tweak whitespace for 'console=' parameter	2018-03-05 14:41:38 -08:00
ide
iio
infiniband	IB: Update references to libibverbs	2018-02-04 11:56:49 -05:00
input	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2018-02-01 10:49:58 -08:00
ioctl	ocxl: Documentation	2018-01-27 20:02:24 +11:00
isdn
kbuild	Documentation updates for 4.16. New stuff includes refcount_t	2018-01-31 19:25:25 -08:00
kdump
kernel-hacking	Documentation: Fix misconversion of #if	2018-01-17 16:45:01 -07:00
laptops	Documentation: fix admin-guide doc refs	2017-10-12 11:13:28 -06:00
leds	Documentation: leds: Update 00-INDEX file	2017-10-23 20:17:03 +02:00
lightnvm
livepatch	livepatch: Remove immediate feature	2018-01-11 10:58:03 +01:00
locking	Documentation/locking/mutex-design: Update to reflect latest changes	2018-02-11 12:28:58 +01:00
m68k
maintainer	docs: Add an intro note to the maintainers handbook	2017-12-11 14:46:10 -07:00
md	raid5-ppl: PPL support for disks with write-back cache enabled	2018-01-15 14:29:42 -08:00
media	media: dvb: add continuity error indicators for memory mapped buffers	2018-02-23 05:28:41 -05:00
memory-devices
metag
mic
mips	Documentation: mips: Update AU1xxx_IDE Kconfig dependencies	2018-02-01 12:45:35 -07:00
misc-devices
mmc
mn10300
mtd	mtd: spi-nor: add an API to restore the status of SPI flash chip	2017-12-13 00:36:00 +01:00
namespaces
netlabel
networking	net/ipv6: Add support for path selection using hash of 5-tuple	2018-03-04 13:04:23 -05:00
nfc
nios2
nvdimm
nvmem	NVMEM documentation fix: A minor typo	2017-08-24 13:31:58 -06:00
openrisc	Documentation: openrisc: Updates to README	2017-10-30 21:37:53 +09:00
parisc
PCI	PCI: Update location of pci.ids file	2018-02-22 15:00:43 -06:00
pcmcia
perf	perf: ARM DynamIQ Shared Unit PMU support	2018-01-02 16:43:12 +00:00
phy
platform
power	regulator: Changes for v4.16	2018-01-29 11:32:44 -08:00
powerpc
pps	drivers/pps: aesthetic tweaks to PPS-related content	2017-09-08 18:26:51 -07:00
process	A few late-arriving fixes, along with Konstantin's PGP document that had	2018-02-07 09:42:59 -08:00
pti
ptp
rapidio
RCU	Merge branches 'cond_resched.2017.12.04a', 'dyntick.2017.11.28a', 'fixes.2017.12.11a', 'srbd.2017.12.05a' and 'torture.2017.12.11a' into HEAD	2017-12-11 09:21:58 -08:00
s390
scheduler	sched/deadline: Fix the description of runtime accounting in the documentation	2017-11-16 09:00:35 +01:00
scsi	scsi: documentation: Fix case of 'scsi_device' struct mention(s)	2017-12-02 08:43:43 -07:00
security	Documentation: security/credentials.rst: explain need to sort group_list	2018-01-08 14:20:31 -07:00
serial
sh
sound	sound updates for 4.15-rc1	2017-11-14 18:01:46 -08:00
sparc	sparc64: Oracle DAX driver	2018-01-22 08:17:16 -08:00
sphinx	linux-next: docs-rst: Fix typos in kfigure.py	2018-01-17 16:49:05 -07:00
sphinx-static
spi
sysctl	net: do not create fallback tunnels for non-default namespaces	2018-03-09 11:23:11 -05:00
target
thermal	cpu_cooling: Remove static-power related documentation	2018-01-03 13:11:48 +01:00
timers	docs: highres: fix broken urls	2017-09-26 14:58:23 -06:00
trace	docs: ftrace-uses.rst fix varios code-block directives	2017-12-21 13:39:31 -07:00
translations	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk	2018-02-01 13:36:15 -08:00
usb	Documentation updates for 4.16. New stuff includes refcount_t	2018-01-31 19:25:25 -08:00
userspace-api
virtual	KVM: x86: Add a framework for supporting MSR-based features	2018-03-01 19:00:28 +01:00
vm	Documentation updates for 4.16. New stuff includes refcount_t	2018-01-31 19:25:25 -08:00
w1	Documentation updates for 4.16. New stuff includes refcount_t	2018-01-31 19:25:25 -08:00
watchdog	documentation: watchdog: remove documentation of w83697hf_wdt/w83697ug_wdt	2018-02-03 11:09:54 +01:00
wimax
x86	Documentation, x86, resctrl: Make text and sample command match	2018-02-28 19:59:05 +01:00
xtensa	xtensa: add support for KASAN	2017-12-16 22:37:12 -08:00
.gitignore
00-INDEX	docs: get rid of kernel-doc-nano-HOWTO.txt	2017-12-21 13:41:46 -07:00
atomic_bitops.txt	locking/atomic/bitops: Document and clarify ordering semantics for failed test_and_{}_bit()	2018-02-13 14:55:53 +01:00
atomic_t.txt	Documentation/locking/atomic: Finish the document...	2017-08-25 11:06:33 +02:00
bcache.txt
bt8xxgpio.txt
btmrvl.txt
bus-virt-phys-mapping.txt
cachetlb.txt
cgroup-v2.txt	cgroup, docs: document the root cgroup behavior of cpu and io controllers	2018-01-16 08:07:09 -08:00
Changes
circular-buffers.txt	doc: De-emphasize smp_read_barrier_depends	2017-12-05 11:57:53 -08:00
clearing-warn-once.txt	kernel debug: support resetting WARN*_ONCE	2017-11-17 16:10:00 -08:00
clk.txt
CodingStyle
conf.py	docs: Remove "could not extract kernel version" warning	2017-12-11 15:20:04 -07:00
cpu-load.txt
cputopology.txt
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt
digsig.txt
DMA-API-HOWTO.txt
DMA-API.txt	dma-coherent: remove the DMA_MEMORY_MAP and DMA_MEMORY_IO flags	2017-09-01 11:59:17 +02:00
DMA-attributes.txt
DMA-ISA-LPC.txt
docutils.conf
dontdiff
efi-stub.txt
eisa.txt
flexible-arrays.txt
futex-requeue-pi.txt
gcc-plugins.txt
highuid.txt
hw_random.txt
hwspinlock.txt
index.rst	Documentation: Add license-rules.rst to describe how to properly identify file licenses	2018-01-06 10:58:02 -07:00
Intel-IOMMU.txt
intel_txt.txt
io-mapping.txt
io_ordering.txt
iostats.txt
IPMI.txt	ipmi: Make IPMI panic strings always available	2017-09-27 16:03:45 -05:00
IRQ-affinity.txt
IRQ-domain.txt	irqdomain: Kill CONFIG_IRQ_DOMAIN_DEBUG	2018-01-24 12:32:58 +01:00
IRQ.txt
irqflags-tracing.txt
isa.txt
isapnp.txt
kernel-per-CPU-kthreads.txt
kobject.txt
kprobes.txt	kprobes/docs: Remove jprobes related documents	2017-10-20 11:02:55 +02:00
kref.txt
ldm.txt
lockup-watchdogs.txt
logo.gif
logo.txt
lsm.txt
lzo.txt
mailbox.txt
Makefile	Documentation: add script and build target to check for broken file references	2017-10-12 11:07:42 -06:00
memory-barriers.txt	doc: De-emphasize smp_read_barrier_depends	2017-12-05 11:57:53 -08:00
memory-hotplug.txt
men-chameleon-bus.txt
nommu-mmap.txt
ntb.txt
numastat.txt
padata.txt
parport-lowlevel.txt
percpu-rw-semaphore.txt
phy.txt
pi-futex.txt	Documentation: fix locking rt-mutex doc refs	2017-10-19 12:56:44 -06:00
pnp.txt
preempt-locking.txt
pwm.txt
rbtree.txt	rbtree: cache leftmost node internally	2017-09-08 18:26:48 -07:00
remoteproc.txt
rfkill.txt
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rtc.txt	Documentation: rtc: move iotcl interface documentation to ABI	2018-01-12 00:20:41 +01:00
SAK.txt
sgi-ioc4.txt
siphash.txt
SM501.txt
smsc_ece1099.txt
speculation.txt	Documentation: Document array_index_nospec	2018-01-30 21:54:28 +01:00
static-keys.txt
SubmittingPatches
svga.txt	documentation/svga.txt: update outdated file	2017-11-20 10:45:50 -07:00
switchtec.txt	NTB: switchtec_ntb: Update switchtec documentation with notes for NTB	2017-11-18 20:37:13 -05:00
sync_file.txt
tee.txt
this_cpu_ops.txt
unaligned-memory-access.txt
vfio-mediated-device.txt
vfio.txt
video-output.txt
xillybus.txt
xz.txt
zorro.txt