Eric Dumazet 33e834ef26 tcp: tsq: restore minimal amount of queueing ... [ Upstream commit 98e09386c0 ] After commit c9eeec26e3 ("tcp: TSQ can use a dynamic limit"), several users reported throughput regressions, notably on mvneta and wifi adapters. 802.11 AMPDU requires a fair amount of queueing to be effective. This patch partially reverts the change done in tcp_write_xmit() so that the minimal amount is sysctl_tcp_limit_output_bytes. It also remove the use of this sysctl while building skb stored in write queue, as TSO autosizing does the right thing anyway. Users with well behaving NICS and correct qdisc (like sch_fq), can then lower the default sysctl_tcp_limit_output_bytes value from 128KB to 8KB. This new usage of sysctl_tcp_limit_output_bytes permits each driver authors to check how their driver performs when/if the value is set to a minimum of 4KB. Normally, line rate for a single TCP flow should be possible, but some drivers rely on timers to perform TX completion and too long TX completion delays prevent reaching full throughput. Fixes: c9eeec26e3 ("tcp: TSQ can use a dynamic limit") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Sujith Manoharan <sujith@msujith.org> Reported-by: Arnaud Ebalard <arno@natisbad.org> Tested-by: Sujith Manoharan <sujith@msujith.org> Cc: Felix Fietkau <nbd@openwrt.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Change-Id: I1fab5c795148dff3da34b42c7808476f51d99f89		2020-11-30 19:35:19 +03:00
..
ABI	netfilter: remove ip_queue support	2018-12-07 22:00:11 +04:00
accounting
acpi	Update documentation for parameter *notrigger* in einj.txt	2012-03-30 03:30:19 -04:00
aoe	Documentation: remove references to /etc/modprobe.conf	2012-03-30 16:03:15 -07:00
arm	uio: msm_sharedmem: Add new device driver for sharedmemory access	2014-07-15 23:59:19 +00:00
auxdisplay
backlight	backlight: new backlight driver for LP855x devices	2012-03-23 16:58:33 -07:00
blackfin
block	block: Add test-iosched scheduler	2013-02-27 18:13:18 -08:00
blockdev	UPSTREAM: zram: deprecate zram attrs sysfs nodes	2018-01-01 21:27:12 +03:00
cdrom
cgroups	memcg: fix/change behavior of shared anon at moving task	2018-01-01 22:02:04 +03:00
connector
console
cpu-freq	cpufreq: interactive: add boost pulse interface	2012-05-03 17:41:51 -07:00
cpuidle	cpuidle: add a sysfs entry to disable specific C state for debug purpose.	2012-03-30 01:52:58 -04:00
cris
crypto	crypto: Add MSM crypto drivers	2013-02-25 11:29:28 -08:00
development-process
device-mapper	dm: verity fix documentation	2012-07-16 09:04:25 -07:00
devicetree	ARM: configs: flo: Go back to 100Hz	2018-03-23 18:43:28 +03:00
DocBook	ALSA: Remove transfer_ack_{begin,end} callbacks from struct snd_pcm_runtime	2017-03-07 05:44:05 +00:00
driver-model	Merge remote-tracking branches 'regulator/topic/devm' and 'regulator/topic/stub' into regulator-next	2012-03-18 21:38:28 +00:00
dvb	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
early-userspace
EDID	drm: allow loading an EDID as firmware to override broken monitor	2012-03-20 10:09:28 +00:00
fault-injection
fb	Documentation: remove references to /etc/modprobe.conf	2012-03-30 16:03:15 -07:00
filesystems	vfs: improve i_op->atomic_open() documentation	2018-12-07 22:28:48 +04:00
firmware_class	firmware loader: document firmware cache mechanism	2017-12-28 12:57:14 +03:00
frv
hid	HID: uhid: add documentation	2013-03-04 12:45:09 -08:00
hwmon	hwmon: (coretemp) Add support for Atom CE4110/4150/4170	2014-04-14 06:44:31 -07:00
i2c	i2c-piix4: Add AMD CZ SMBus device ID	2014-06-07 16:02:14 -07:00
i2o	Documentation: Fix multiple typo in Documentation	2012-03-07 16:08:24 +01:00
ia64
ide	Documentation: remove references to /etc/modprobe.conf	2012-03-30 16:03:15 -07:00
infiniband
input	Documentation: input.txt: clarify mousedev 'cat' command syntax	2012-03-30 16:03:15 -07:00
ioctl	Merge branch 'for-next' of git://gitorious.org/kernel-hsi/kernel-hsi	2012-04-02 09:50:40 -07:00
isdn	Documentation: remove references to /etc/modprobe.conf	2012-03-30 16:03:15 -07:00
ja_JP	Documentation: Update stable address in Chinese and Japanese translations	2014-06-07 16:02:02 -07:00
kbuild	Documentation: mention scripts/diffconfig tool	2012-03-30 16:03:15 -07:00
kdump
ko_KR
laptops	Documentation: remove references to /etc/modprobe.conf	2012-03-30 16:03:15 -07:00
leds	drivers/leds/leds-lp5521.c: support led pattern data	2012-03-23 16:58:34 -07:00
m68k
make
mips
misc-devices
mmc	mmc: use percentage changed sectors as indication to check BKOPS need	2013-03-15 17:08:16 -07:00
mn10300
mtd	mtd: msm_qpic_nand: Initial driver for QPIC based NAND controller	2013-02-27 18:17:42 -08:00
namespaces
netlabel
networking	tcp: tsq: restore minimal amount of queueing	2020-11-30 19:35:19 +03:00
nfc
parisc
PCI
pcmcia
power	Documentation: Point to correct header file	2013-02-25 11:36:56 -08:00
powerpc	Documentation/powerpc/mpc52xx.txt: Checkpatch cleanup	2012-03-18 23:59:34 +01:00
pps
prctl	Documentation: prctl/seccomp_filter	2014-10-31 19:46:17 -07:00
pti
ptp
rapidio
RCU
s390	Documentation: remove references to /etc/modprobe.conf	2012-03-30 16:03:15 -07:00
scheduler
scsi	SCSI updates on 20120331	2012-03-31 13:31:23 -07:00
security	KEYS: Add invalidation support	2016-10-29 23:12:12 +08:00
serial	Documentation: remove references to /etc/modprobe.conf	2012-03-30 16:03:15 -07:00
sh
sound	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
sparc
spi	spi: create a message queueing infrastructure	2012-03-07 19:19:48 -07:00
sysctl	fs: add link restrictions	2018-12-07 22:28:48 +04:00
target
telephony
thermal
timers	time: Remove CONFIG_TIMER_STATS	2017-07-02 13:03:26 +03:00
trace	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2012-03-20 21:12:50 -07:00
usb	usb: misc: Add kickstart bridge driver	2013-02-27 18:19:01 -08:00
vDSO
video4linux	Documentation: remove references to /etc/modprobe.conf	2012-03-30 16:03:15 -07:00
virtual	Merge branch 'kvm-updates/3.4' of git://git.kernel.org/pub/scm/virt/kvm/kvm	2012-03-28 14:35:31 -07:00
vm	UPSTREAM: zsmalloc: zsmalloc documentation	2018-01-01 21:27:11 +03:00
w1
watchdog	watchdog: Add support for WDIOC_GETTIMELEFT IOCTL in watchdog core	2012-03-27 20:15:37 +02:00
wimax
x86	x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stack	2014-08-07 12:00:10 -07:00
zh_CN	Documentation: Update stable address in Chinese and Japanese translations	2014-06-07 16:02:02 -07:00
.gitignore
00-INDEX	crc32: move long comment about crc32 fundamentals to Documentation/	2012-03-23 16:58:37 -07:00
android.txt	[docs] android: Add android config documentation to boot framework.	2012-04-09 13:53:13 -07:00
applying-patches.txt
atomic_ops.txt
bad_memory.txt
basic_profiling.txt
binfmt_misc.txt
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
BUG-HUNTING
bus-virt-phys-mapping.txt
cachetlb.txt
Changes
circular-buffers.txt
clk.txt	Documentation: common clk API	2012-03-16 20:35:01 +00:00
coccinelle.txt
CodingStyle	Documentation: CodingStyle: add inline assembly guidelines	2012-03-30 16:03:15 -07:00
cpu-hotplug.txt	documentation: remove references to cpu_*_map.	2012-03-29 15:38:31 +10:30
cpu-load.txt
cputopology.txt
crc32.txt	crc32: move long comment about crc32 fundamentals to Documentation/	2012-03-23 16:58:37 -07:00
csdio.txt	mmc: Char SDIO Device Driver	2013-02-25 11:29:22 -08:00
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt
devices.txt
digsig.txt
DMA-API-HOWTO.txt
DMA-API.txt
DMA-attributes.txt	common: DMA-mapping: Add strongly ordered memory attribute	2013-03-07 15:23:21 -08:00
dma-buf-sharing.txt	dma-buf: mmap support	2012-05-22 14:01:06 -07:00
DMA-ISA-LPC.txt
dmaengine.txt	Documentation: Fix multiple typo in Documentation	2012-03-07 16:08:24 +01:00
dontdiff	Documentation: remove 'mach' from dontdiff file	2012-03-30 16:03:15 -07:00
dynamic-debug-howto.txt
edac.txt	EDAC: Correct scrub rate API	2012-03-19 12:03:58 +01:00
eisa.txt
email-clients.txt
feature-removal-schedule.txt	netfilter: remove xt_NOTRACK	2018-12-07 22:04:24 +04:00
flexible-arrays.txt
futex-requeue-pi.txt
gcov.txt
genlock.txt	base: genlock: allow synchronization with a single gralloc handle	2013-02-25 11:29:17 -08:00
gpio.txt	Documentation/gpio.txt: Explain expected pinctrl interaction	2012-03-12 11:27:07 -06:00
highuid.txt
HOWTO	docs: update HOWTO for 2.6.x -> 3.x versioning	2012-06-01 15:18:18 +08:00
hw_random.txt
hwspinlock.txt
init.txt
initrd.txt
Intel-IOMMU.txt
intel_txt.txt
io-mapping.txt
io_ordering.txt
iostats.txt
IPMI.txt
IRQ-affinity.txt
IRQ-domain.txt
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kernel-doc-nano-HOWTO.txt
kernel-docs.txt
kernel-parameters.txt	Merge remote-tracking branch 'stable/linux-3.4.y' into lineage-15.1	2017-12-27 17:13:15 +03:00
kmemcheck.txt
kmemleak.txt
kobject.txt
kprobes.txt
kref.txt
ldm.txt
local_ops.txt
lockdep-design.txt
lockstat.txt
lockup-watchdogs.txt
logo.gif
logo.txt
lzo.txt	Documentation: lzo: document part of the encoding	2015-02-02 17:04:43 +08:00
magic-number.txt
Makefile	mm: move hugepage test examples to tools/testing/selftests/vm	2012-03-28 17:14:37 -07:00
ManagementStyle
mca.txt
md.txt
media-framework.txt
memory-barriers.txt
memory-hotplug.txt
memory.txt
mono.txt	Documentation: remove references to /etc/modprobe.conf	2012-03-30 16:03:15 -07:00
mutex-design.txt
nommu-mmap.txt
numastat.txt	Doc: Update numastat.txt	2012-02-28 16:05:06 +01:00
oops-tracing.txt
padata.txt
parport-lowlevel.txt
parport.txt	Documentation: remove references to /etc/modprobe.conf	2012-03-30 16:03:15 -07:00
pi-futex.txt
pinctrl.txt	pinctrl: fix example .get_group_pins implementation signature	2015-09-18 09:20:24 +08:00
pnp.txt
preempt-locking.txt
printk-formats.txt
prio_tree.txt
ramoops.txt
rbtree.txt
remoteproc.txt	remoteproc: remove the single rpmsg vdev limitation	2012-03-06 19:14:12 +02:00
rfkill.txt
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt
rt-mutex-design.txt
rt-mutex.txt
rtc.txt
SAK.txt
SecurityBugs
serial-console.txt
sgi-ioc4.txt
sgi-visws.txt
SM501.txt
sparse.txt
spinlocks.txt
stable_api_nonsense.txt
stable_kernel_rules.txt	stable_kernel_rules: Add pointer to netdev-FAQ for network patches	2014-09-25 11:49:09 +08:00
static-keys.txt	static keys: Add docs better explaining the whole 'struct static_key' mechanism	2012-02-24 09:12:19 +01:00
SubmitChecklist
SubmittingDrivers
SubmittingPatches
svga.txt
sync.txt	sync: add Documentation/sync.txt	2013-03-15 17:13:08 -07:00
sysfs-rules.txt
sysrq.txt	Documentation: sysrq: Crutcher Dunnavant is unavailable	2012-03-30 16:03:15 -07:00
unaligned-memory-access.txt
unicode.txt
unshare.txt
VGA-softcursor.txt
vgaarbiter.txt
video-output.txt
volatile-considered-harmful.txt
workqueue.txt
xz.txt
zorro.txt