Eric Dumazet 5e25ba5003 tcp: TSO packets automatic sizing ... [ Upstream commits 6d36824e730f247b602c90e8715a792003e3c5a7, 02cf4ebd82ff0ac7254b88e466820a290ed8289a, and parts of 7eec4174ff29cd42f2acfae8112f51c228545d40 ] After hearing many people over past years complaining against TSO being bursty or even buggy, we are proud to present automatic sizing of TSO packets. One part of the problem is that tcp_tso_should_defer() uses an heuristic relying on upcoming ACKS instead of a timer, but more generally, having big TSO packets makes little sense for low rates, as it tends to create micro bursts on the network, and general consensus is to reduce the buffering amount. This patch introduces a per socket sk_pacing_rate, that approximates the current sending rate, and allows us to size the TSO packets so that we try to send one packet every ms. This field could be set by other transports. Patch has no impact for high speed flows, where having large TSO packets makes sense to reach line rate. For other flows, this helps better packet scheduling and ACK clocking. This patch increases performance of TCP flows in lossy environments. A new sysctl (tcp_min_tso_segs) is added, to specify the minimal size of a TSO packet (default being 2). A follow-up patch will provide a new packet scheduler (FQ), using sk_pacing_rate as an input to perform optional per flow pacing. This explains why we chose to set sk_pacing_rate to twice the current rate, allowing 'slow start' ramp up. sk_pacing_rate = 2 * cwnd * mss / srtt v2: Neal Cardwell reported a suspect deferring of last two segments on initial write of 10 MSS, I had to change tcp_tso_should_defer() to take into account tp->xmit_size_goal_segs Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Van Jacobson <vanj@google.com> Cc: Tom Herbert <therbert@google.com> Acked-by: Yuchung Cheng <ycheng@google.com> Acked-by: Neal Cardwell <ncardwell@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2013-11-04 04:30:59 -08:00
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ABI	- Lots of cleanups from Artem, including deletion of some obsolete drivers	2013-05-09 10:15:46 -07:00
DocBook	media: DocBook: upgrade media_api DocBook version to 4.2	2013-09-26 17:18:20 -07:00
EDID	drm: Add 1600x1200 (UXGA) screen resolution to the built-in EDIDs	2013-04-12 14:06:16 +10:00
PCI	…
RCU	Merge commit '8700c95adb03' into timers/nohz	2013-05-02 17:54:19 +02:00
accounting	…
acpi	Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma	2013-05-09 09:46:45 -07:00
aoe	…
arm	ARM: platform specific firmware interfaces for 3.10	2013-05-04 12:33:36 -07:00
arm64	…
auxdisplay	…
backlight	backlight: lp855x: remove duplicate platform data	2013-04-29 18:28:19 -07:00
blackfin	…
block	Documentation: cfq-iosched: update documentation help for cfq tunables	2013-04-09 14:57:06 +02:00
blockdev	nbd: update documentation and link to mailinglist	2013-02-27 19:10:22 -08:00
bus-devices	…
cdrom	…
cgroups	mm, memcg: add rss_huge stat to memory.stat	2013-05-07 18:38:26 -07:00
connector	…
console	…
cpu-freq	Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-05-05 13:23:27 -07:00
cpuidle	cpuidle: make a single register function for all	2013-04-23 13:45:22 +02:00
cris	…
crypto	…
development-process	…
device-mapper	DM RAID: Add message/status support for changing sync action	2013-04-24 11:42:43 +10:00
devicetree	Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media	2013-06-18 06:25:08 -10:00
driver-model	…
dvb	…
early-userspace	…
extcon	…
fault-injection	…
fb	…
filesystems	xfs: disable noattr2/attr2 mount options for CRC enabled filesystems	2013-06-06 10:51:34 -05:00
firmware_class	…
frv	…
hid	…
hwmon	hwmon: (k10temp) Add support for Fam16h (Kabini)	2013-09-07 22:09:59 -07:00
i2c	i2c-piix4: Add AMD CZ SMBus device ID	2013-07-25 14:07:28 -07:00
i2o	…
ia64	Fix example error_injection_tool	2013-04-02 09:39:55 -07:00
ide	…
infiniband	…
input	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2013-03-11 07:49:37 -07:00
ioctl	USB: cdc-wdm: implement IOCTL_WDM_MAX_COMMAND	2013-03-25 13:32:20 -07:00
isdn	…
ja_JP	…
kbuild	Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild	2013-05-07 07:59:19 -07:00
kdump	Add size restriction to the kdump documentation	2013-04-02 09:40:03 -07:00
ko_KR	…
laptops	…
leds	leds: lp55xx: configure the clock detection	2013-04-01 11:04:53 -07:00
m68k	block: remove refs to XD disks from documentation	2013-05-17 15:17:12 +02:00
make	…
memory-devices	…
metag	metag: Basic documentation	2013-03-02 20:09:50 +00:00
mips	…
misc-devices	mei: bus: Add device enabling and disabling API	2013-04-08 16:57:15 -07:00
mmc	mmc: core: Add in support to expose PRV for v4 MMCs	2013-03-22 12:10:42 -04:00
mn10300	…
mtd	…
namespaces	…
netlabel	…
networking	tcp: TSO packets automatic sizing	2013-11-04 04:30:59 -08:00
nfc	…
parisc	parisc: document the shadow registers	2013-07-21 18:21:26 -07:00
pcmcia	…
power	PM / hibernate: Correct documentation	2013-05-14 01:58:43 +02:00
powerpc	powerpc/tm: Fix userspace stack corruption on signal delivery for active transactions	2013-06-01 08:29:23 +10:00
pps	…
prctl	…
pti	…
ptp	…
rapidio	rapidio: documentation update for enumeration changes	2013-05-24 16:22:50 -07:00
s390	s390/cio: add condev keyword to cio_ignore	2013-05-02 15:50:20 +02:00
scheduler	…
scsi	[SCSI] qla2xxx: Update copyright dates information in LICENSE.qla2xxx file.	2013-04-06 11:31:30 +01:00
security	Smack: add support for modification of existing rules	2013-03-19 14:16:42 -07:00
serial	…
sh	…
sound	ALSA: hda - Add models for Dell headset jacks	2013-06-17 11:15:56 +02:00
spi	…
sysctl	mm: replace hardcoded 3% with admin_reserve_pages knob	2013-04-29 15:54:36 -07:00
target	…
thermal	Thermal: update documentation for thermal_zone_device_register	2013-04-27 09:16:04 +08:00
timers	nohz_full: Add documentation.	2013-04-27 16:41:43 -07:00
trace	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2013-04-30 09:36:50 -07:00
usb	USB: remove CONFIG_USB_SUSPEND from Documentation	2013-03-28 14:45:56 -07:00
vDSO	…
video4linux	[media] v4l2: Add a V4L2 driver for SI476X MFD	2013-04-18 21:20:34 -03:00
virtual	Merge tag 'kvm-3.10-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm	2013-05-05 14:47:31 -07:00
vm	mm: limit growth of 3% hardcoded other user reserve	2013-04-29 15:54:36 -07:00
w1	w1: w1_therm: Add force-pullup option for "broken" sensors	2013-02-18 13:55:24 -08:00
watchdog	watchdog: core: dt: add support for the timeout-sec dt property	2013-03-01 12:48:36 +01:00
wimax	…
x86	Merge branch 'x86-debug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-04-30 08:35:20 -07:00
xtensa	xtensa: document MMUv3 setup sequence	2013-05-09 01:07:09 -07:00
zh_CN	gpio: update gpio Chinese documentation	2013-04-16 18:47:22 +09:00
.gitignore	…
00-INDEX	ImgTec Meta architecture changes for v3.9-rc1	2013-03-03 12:06:09 -08:00
BUG-HUNTING	…
Changes	…
CodingStyle	…
DMA-API-HOWTO.txt	Documentation/DMA-API-HOWTO.txt: fix typo	2013-02-27 19:10:23 -08:00
DMA-API.txt	…
DMA-ISA-LPC.txt	…
DMA-attributes.txt	…
HOWTO	…
IPMI.txt	ipmi: add options to disable openfirmware and PCI scanning	2013-02-27 19:10:21 -08:00
IRQ-affinity.txt	…
IRQ-domain.txt	…
IRQ.txt	…
Intel-IOMMU.txt	…
Makefile	…
ManagementStyle	…
SAK.txt	…
SM501.txt	…
SecurityBugs	…
SubmitChecklist	…
SubmittingDrivers	…
SubmittingPatches	checkpatch: add Suggested-by as a standard signature	2013-04-29 18:28:20 -07:00
VGA-softcursor.txt	…
applying-patches.txt	…
atomic_ops.txt	…
bad_memory.txt	…
basic_profiling.txt	…
bcache.txt	bcache: clarify free/available/unused space	2013-05-15 00:42:52 -07:00
binfmt_misc.txt	…
braille-console.txt	…
bt8xxgpio.txt	…
btmrvl.txt	…
bus-virt-phys-mapping.txt	…
cachetlb.txt	…
circular-buffers.txt	…
clk.txt	clk: add clk_ignore_unused option to keep boot clocks on	2013-04-27 23:03:43 -07:00
coccinelle.txt	Coccinelle: Add support to the SPFLAGS variable	2013-04-08 15:42:03 +02:00
cpu-hotplug.txt	…
cpu-load.txt	…
cputopology.txt	…
crc32.txt	…
dcdbas.txt	…
debugging-modules.txt	…
debugging-via-ohci1394.txt	…
dell_rbu.txt	…
devices.txt	block: remove refs to XD disks from documentation	2013-05-17 15:17:12 +02:00
digsig.txt	…
dma-buf-sharing.txt	dma-buf: replace dma_buf_export() with dma_buf_export_named()	2013-05-01 16:35:36 +05:30
dmaengine.txt	…
dmatest.txt	dmatest: do not allow to interrupt ongoing tests	2013-06-08 02:13:44 +05:30
dontdiff	…
dynamic-debug-howto.txt	…
edac.txt	…
eisa.txt	…
email-clients.txt	…
flexible-arrays.txt	…
futex-requeue-pi.txt	…
gcov.txt	…
gpio.txt	Remove GENERIC_GPIO config option	2013-04-16 18:47:19 +09:00
highuid.txt	…
hw_random.txt	hwrng: Fix a wrong comment in Documentation/hw_random.txt	2013-03-10 18:16:36 +08:00
hwspinlock.txt	…
init.txt	…
initrd.txt	…
intel_txt.txt	…
io-mapping.txt	…
io_ordering.txt	…
iostats.txt	iostats.txt: add easy-to-find description for field 6	2013-04-29 15:18:50 +02:00
irqflags-tracing.txt	…
isapnp.txt	…
java.txt	…
kernel-doc-nano-HOWTO.txt	…
kernel-docs.txt	…
kernel-parameters.txt	Merge branch 'for-linus' of git://git.kernel.dk/linux-block	2013-06-12 16:42:39 -07:00
kernel-per-CPU-kthreads.txt	kthread: Document ways of reducing OS jitter due to per-CPU kthreads	2013-04-27 16:52:47 -07:00
kmemcheck.txt	…
kmemleak.txt	…
kobject.txt	…
kprobes.txt	…
kref.txt	…
ldm.txt	…
local_ops.txt	…
lockdep-design.txt	…
lockstat.txt	locking/stat: Fix a typo	2013-02-19 08:42:37 +01:00
lockup-watchdogs.txt	…
logo.gif	…
logo.txt	…
magic-number.txt	wanrouter: completely decouple obsolete code from kernel.	2013-01-31 19:20:33 -05:00
md.txt	MD: Fix typos in MD documentation	2013-04-24 11:42:42 +10:00
media-framework.txt	[media] Documentation/media-framework.txt: fix a sentence	2013-02-08 13:27:13 -02:00
memory-barriers.txt	…
memory-hotplug.txt	…
mono.txt	…
mutex-design.txt	…
nommu-mmap.txt	…
numastat.txt	…
oops-tracing.txt	…
padata.txt	…
parport-lowlevel.txt	…
parport.txt	…
percpu-rw-semaphore.txt	…
pi-futex.txt	…
pinctrl.txt	pinctrl: document the "GPIO mode" pitfall	2013-03-18 11:03:29 +01:00
pnp.txt	…
preempt-locking.txt	…
printk-formats.txt	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2013-04-30 13:47:37 -07:00
pwm.txt	…
ramoops.txt	…
rbtree.txt	…
remoteproc.txt	…
rfkill.txt	…
robust-futex-ABI.txt	…
robust-futexes.txt	…
rpmsg.txt	…
rt-mutex-design.txt	…
rt-mutex.txt	…
rtc.txt	…
serial-console.txt	…
sgi-ioc4.txt	…
sgi-visws.txt	…
smsc_ece1099.txt	…
sparse.txt	…
spinlocks.txt	…
stable_api_nonsense.txt	…
stable_kernel_rules.txt	…
static-keys.txt	…
svga.txt	…
sysfs-rules.txt	…
sysrq.txt	Documentation/sysrq: fix inconstistent help message of sysrq key	2013-04-30 17:04:10 -07:00
this_cpu_ops.txt	percpu: add documentation on this_cpu operations	2013-04-04 10:24:53 -07:00
unaligned-memory-access.txt	…
unicode.txt	…
unshare.txt	…
vfio.txt	…
vgaarbiter.txt	…
video-output.txt	…
vme_api.txt	…
volatile-considered-harmful.txt	…
workqueue.txt	…
xz.txt	…
zorro.txt	…