linux/Documentation
Eric Dumazet 98e09386c0 tcp: tsq: restore minimal amount of queueing
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>
2013-11-14 16:25:14 -05:00
..
ABI Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-11-13 17:40:34 +09:00
DocBook Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-11-13 17:40:34 +09:00
EDID drm: Add 1600x1200 (UXGA) screen resolution to the built-in EDIDs 2013-04-12 14:06:16 +10:00
PCI PCI/MSI: Enable multiple MSIs with pci_enable_msi_block_auto() 2013-01-24 17:25:13 +01:00
RCU rcu: Fix occurrence of "the the" in checklist.txt 2013-09-25 10:07:02 -07:00
accounting Documentation/accounting/getdelays.c: avoid strncpy in accounting tool 2013-07-03 16:08:06 -07:00
acpi gpiolib / ACPI: document the GPIO descriptor based interface 2013-10-19 23:32:50 +02:00
aoe aoe: remove do-nothing NAME="%k" term from example udev rules 2013-09-11 15:59:28 -07:00
arm Allwinner sunXi SoCs machine additions for 3.13 2013-10-28 10:19:38 -07:00
arm64 arm64: Use 42-bit address space with 64K pages 2013-11-05 17:23:52 +00:00
auxdisplay
backlight backlight: lp855x_bl: support new LP8555 device 2013-11-13 12:09:14 +09:00
blackfin
block block: change config option name for cmdline partition parsing 2013-09-30 14:31:02 -07:00
blockdev nbd: update documentation and link to mailinglist 2013-02-27 19:10:22 -08:00
bus-devices ARM: OMAP2+: gpmc: generic timing calculation 2012-11-09 18:07:11 +05:30
cdrom
cgroups memcg: support hierarchical memory.numa_stats 2013-11-13 12:09:06 +09:00
connector connector - documentation: simplify netlink message length assignment 2013-10-02 16:03:51 -04:00
console TTY:console: update document console.txt 2013-05-21 10:21:57 -07:00
cpu-freq cpufreq: Drop the owner field from struct cpufreq_driver 2013-08-10 03:24:47 +02:00
cpuidle cpuidle: make a single register function for all 2013-04-23 13:45:22 +02:00
cris
crypto drivers/dma: remove unused support for MEMSET operations 2013-07-03 16:07:42 -07:00
development-process Documentation: development-process: Update -mm and -next URLs 2013-07-25 12:37:24 +02:00
device-mapper dm: add statistics support 2013-09-05 20:46:06 -04:00
devicetree Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-11-13 17:40:34 +09:00
driver-model spi: Updates for v3.13 2013-11-12 15:01:39 +09:00
dvb [media] get_dvb_firmware: Fix the location of firmware for Terratec HTC 2013-01-01 11:18:26 -02:00
early-userspace Documentation: remove reference to 2.7 kernel in early-userspace 2013-08-20 12:47:28 +02:00
extcon extcon: Simplify extcon_dev_register() prototype by removing unnecessary parameter 2013-09-27 09:37:01 +09:00
fault-injection doc: fix quite a few typos within Documentation 2012-11-19 14:28:24 +01:00
fb Documentation/fb/viafb.modes fix a typo 2013-08-20 12:41:11 +02:00
filesystems Merge branch 'akpm' (patches from Andrew Morton) 2013-11-13 15:45:43 +09:00
firmware_class firmware loader: document firmware cache mechanism 2012-11-14 15:07:18 -08:00
fmc doc: Fix typo "is is" in Documentations 2013-08-27 10:50:52 +02:00
frv
hid HID: uhid: use generic hidinput_input_event() 2013-07-31 10:33:05 +02:00
hwmon hwmon: (pmbus/ltc2978): Add support for LTC2978A 2013-10-18 09:12:03 -07:00
i2c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-09-06 09:36:28 -07:00
i2o
ia64 Fix example error_injection_tool 2013-04-02 09:39:55 -07:00
ide
infiniband IB/ipoib: Add rtnl_link_ops support 2012-09-20 16:49:17 -04:00
input Merge branch 'master' into for-3.12/upstream 2013-09-04 10:49:57 +02:00
ioctl ALSA: add DICE driver 2013-10-17 21:18:32 +02:00
isdn
ja_JP HOWTO ja_JP sync 2013-07-24 22:06:34 -07:00
kbuild kconfig: do not allow more than one symbol to have 'option modules' 2013-09-05 11:10:08 +02:00
kdump Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-07-04 11:40:58 -07:00
ko_KR Correct unfaithful translation on HOWTO in ko_KR 2013-08-12 17:43:13 -07:00
laptops thinkpad-acpi: Add mute and mic-mute LED functionality 2013-10-17 14:38:44 +02:00
leds Documentation: leds-lp5521,lp5523: update device attribute information 2013-08-26 17:22:13 -07:00
m68k block: remove refs to XD disks from documentation 2013-05-17 15:17:12 +02:00
make
memory-devices
metag doc: fix misspellings with 'codespell' tool 2013-05-28 12:02:12 +02:00
mic misc: mic: Enable OSPM suspend and resume support. 2013-10-05 18:01:42 -07:00
mips
misc-devices doc: fix misspellings with 'codespell' tool 2013-05-28 12:02:12 +02:00
mmc mmc: core: Add in support to expose PRV for v4 MMCs 2013-03-22 12:10:42 -04:00
mn10300
mtd doc: Fix typo "is is" in Documentations 2013-08-27 10:50:52 +02:00
namespaces userns: Recommend use of memory control groups. 2013-01-26 22:20:06 -08:00
netlabel
networking tcp: tsq: restore minimal amount of queueing 2013-11-14 16:25:14 -05:00
nfc NFC: Update pn544 documentation 2013-01-10 01:27:46 +01:00
parisc parisc: document the shadow registers 2013-07-09 22:09:19 +02:00
pcmcia
power power: Documentation: Update s2ram link 2013-08-27 10:54:52 +02:00
powerpc powerpc: Update the 00-Index in Documentation/powerpc 2013-08-27 14:44:27 +10:00
pps USB: serial: invoke dcd_change ldisc's handler. 2013-09-26 09:45:40 -07:00
prctl seccomp: Make syscall skipping and nr changes more consistent 2012-10-02 21:14:29 +10:00
pti
ptp ptp: add the PTP_SYS_OFFSET ioctl to the testptp program 2013-09-23 16:46:17 -04:00
rapidio doc: Fix typo in doucmentations 2013-07-25 12:34:15 +02:00
s390 s390/s390dbf: add debug_level_enabled() function 2013-10-24 17:16:53 +02:00
scheduler H8/300 has been dead for several years, the kernel for it has 2013-11-12 14:13:14 +09:00
scsi SCSI misc on 20130915 2013-09-15 17:41:30 -04:00
security Smack: add support for modification of existing rules 2013-03-19 14:16:42 -07:00
serial serial: core: delete .set_wake() callback 2013-10-16 13:16:19 -07:00
sh
sound ALSA: Fix typo in documentation/alsa 2013-10-29 11:38:04 +01:00
spi spi/documentation: Fix usage of __initdata 2013-08-20 12:52:28 +02:00
sysctl vsprintf: check real user/group id for %pK 2013-11-13 12:09:14 +09:00
target Documentation: replace strict_strtoul() with kstrtoul() 2013-08-20 12:56:26 +02:00
thermal thermal: thermal_core: allow binding with limits on bind_params 2013-09-03 09:10:24 -04:00
timers nohz_full: Add testing information to documentation 2013-08-18 18:06:55 -07:00
tpm drivers/tpm: add xen tpmfront interface 2013-08-09 10:57:06 -04:00
trace Documentation/trace/tracepoints.txt: add links to TRACE_EVENT documentation 2013-11-13 12:09:32 +09:00
usb proc_usb_info.txt: Correct documentation about endianness of config descriptors 2013-08-12 12:24:27 -07:00
vDSO
video4linux [media] V4L: Add support for integer menu controls with standard menu items 2013-08-18 07:12:59 -03:00
virtual Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-09-06 09:36:28 -07:00
vm Documentation/vm/zswap.txt: fix typos 2013-11-13 12:09:05 +09:00
w1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-07-04 11:40:58 -07:00
watchdog watchdog: delete mpcore_wdt driver 2013-07-11 21:47:58 +02:00
wimax
x86 Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-11-12 10:48:30 +09:00
xtensa xtensa: document MMUv3 setup sequence 2013-05-09 01:07:09 -07:00
zh_CN Documentation/zh_CN/SubmittingPatches fix a typo 2013-08-20 12:41:25 +02:00
.gitignore
00-INDEX doc: fix a typo in Documentation/00-INDEX 2013-08-27 10:53:07 +02:00
BUG-HUNTING
Changes
CodingStyle Documentation/CodingStyle: allow multiple return statements per function 2013-07-03 16:08:01 -07:00
DMA-API-HOWTO.txt Documentation/DMA-API-HOWTO.txt: fix typo 2013-02-27 19:10:23 -08:00
DMA-API.txt dma-debug: New interfaces to debug dma mapping errors 2012-10-24 17:06:43 +02:00
DMA-ISA-LPC.txt
DMA-attributes.txt common: DMA-mapping: add DMA_ATTR_FORCE_CONTIGUOUS attribute 2012-11-29 03:30:34 -08:00
HOWTO Documentation: Updated broken link in HOWTO 2013-06-03 14:22:57 -07:00
IPMI.txt ipmi: add options to disable openfirmware and PCI scanning 2013-02-27 19:10:21 -08:00
IRQ-affinity.txt doc: fix a typo about irq affinity 2013-08-20 12:59:18 +02:00
IRQ-domain.txt irqdomain: update documentation 2012-12-05 23:52:10 +00:00
IRQ.txt
Intel-IOMMU.txt
Makefile
ManagementStyle
SAK.txt
SM501.txt
SecurityBugs
SubmitChecklist Finally eradicate CONFIG_HOTPLUG 2013-06-03 14:20:18 -07:00
SubmittingDrivers
SubmittingPatches Documentation/SubmittingPatches: Request summaries for commit references 2013-08-20 12:58:15 +02:00
VGA-softcursor.txt
applying-patches.txt
atomic_ops.txt Documentation: Memory barrier semantics of atomic_xchg() 2013-01-08 14:14:55 -08:00
bad_memory.txt
basic_profiling.txt
bcache.txt Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-07-04 11:40:58 -07:00
binfmt_misc.txt
braille-console.txt
bt8xxgpio.txt
btmrvl.txt
bus-virt-phys-mapping.txt
cachetlb.txt Documentation: fix typo and update version in cachetlb.txt 2013-08-20 12:46:52 +02:00
circular-buffers.txt
clk.txt clk: add support for clock reparent on set_rate 2013-08-19 12:27:17 -07:00
coccinelle.txt Coccinelle: Update information about the minimal version required 2013-07-03 22:58:20 +02:00
cpu-hotplug.txt MAINTAINERS: update Zwane Mwaikambo's e-mail address 2013-11-13 12:09:14 +09:00
cpu-load.txt
cputopology.txt doc: Documentation/cputopology.txt fix typo 2013-09-04 12:59:47 +02:00
crc32.txt
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt
dell_rbu.txt
devices.txt cuse: add fix minor number to /dev/cuse 2013-10-01 16:44:54 +02:00
digsig.txt
dma-buf-sharing.txt dma-buf: Expose buffer size to userspace (v2) 2013-09-10 11:36:45 +05:30
dmaengine.txt
dmatest.txt dmatest: make module parameters writable 2013-08-22 22:57:32 -07:00
dontdiff x86: remove offsets.h from .gitignore and dontdiff 2012-11-19 14:10:53 +01:00
dynamic-debug-howto.txt doc: fix misspellings with 'codespell' tool 2013-05-28 12:02:12 +02:00
edac.txt Merge branch 'devel' 2012-07-29 21:11:05 -03:00
efi-stub.txt EFI stub documentation updates 2013-09-25 12:34:32 +01:00
eisa.txt
email-clients.txt
flexible-arrays.txt
futex-requeue-pi.txt
gcov.txt gcov: compile specific gcov implementation based on gcc version 2013-11-13 12:09:34 +09:00
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 doc: documentation/hwspinlock.txt fix typo 2013-08-27 10:46:02 +02:00
init.txt
initrd.txt
intel_txt.txt Documentation: remove depends on CONFIG_EXPERIMENTAL 2013-01-11 11:38:03 -08:00
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-doc: Update references to SGML to refs to XML instead. 2013-05-28 12:02:11 +02:00
kernel-docs.txt
kernel-parameters.txt drivers/char/hpet.c: allow user controlled mmap for user processes 2013-11-13 12:09:11 +09:00
kernel-per-CPU-kthreads.txt kthread: Add pointer to vmstat-avoidance patch 2013-09-25 06:49:46 -07:00
kmemcheck.txt Documentation/kmemcheck: update kmemcheck documentation 2013-08-27 10:47:05 +02:00
kmemleak.txt
kobject.txt Documentation: Fix "struct kobj_type" to include newer members. 2012-09-04 16:06:34 -07:00
kprobes.txt
kref.txt kref: Add kref_get_unless_zero documentation 2012-11-28 18:36:06 +10:00
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: remove doubled description for sync_max, merging it within sync_min/sync_max 2013-07-03 09:43:28 +10:00
media-framework.txt Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media 2013-07-13 12:09:57 -07:00
memory-barriers.txt doc: Fix memory-barrier control-dependency example 2013-08-19 21:39:42 -07:00
memory-hotplug.txt Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-09-06 09:36:28 -07:00
mono.txt
mutex-design.txt
nommu-mmap.txt
numastat.txt
oops-tracing.txt
padata.txt
parport-lowlevel.txt
parport.txt
percpu-rw-semaphore.txt percpu-rw-semaphore: fix documentation typos 2012-09-26 19:56:15 +02:00
phy.txt drivers: phy: add generic PHY framework 2013-09-27 17:35:41 -07:00
pi-futex.txt
pinctrl.txt pinctrl: add documentation for pinctrl_get_group_pins() 2013-10-16 15:35:21 +02:00
pnp.txt
preempt-locking.txt
printk-formats.txt Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-09-06 09:36:28 -07:00
pwm.txt pwm: Add sysfs interface 2013-06-21 11:32:51 +02:00
ramoops.txt pstore/ftrace: Convert to its own enable/disable debugfs knob 2012-09-06 22:16:58 -07:00
rbtree.txt rbtree: move augmented rbtree functionality to rbtree_augmented.h 2012-10-09 16:22:40 +09:00
remoteproc.txt remoteproc: add rproc_report_crash function to notify rproc crashes 2012-09-18 12:53:22 +03:00
rfkill.txt
robust-futex-ABI.txt
robust-futexes.txt
rpmsg.txt Documentation: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
rt-mutex-design.txt sched: Rename sched.c as sched/core.c in comments and Documentation 2013-06-19 12:58:42 +02:00
rt-mutex.txt
rtc.txt rtc: add ability to push out an existing wakealarm using sysfs 2013-07-03 16:07:54 -07:00
serial-console.txt
sgi-ioc4.txt
sgi-visws.txt
smsc_ece1099.txt mfd: smsc: Add support for smsc gpio io/keypad driver 2012-10-01 15:27:48 +02:00
sparse.txt Documentation/sparse.txt: document context annotations for lock checking 2012-12-17 17:15:23 -08:00
spinlocks.txt sched: Rename sched.c as sched/core.c in comments and Documentation 2013-06-19 12:58:42 +02:00
stable_api_nonsense.txt
stable_kernel_rules.txt
static-keys.txt
svga.txt
sysfs-rules.txt doc: Fix typo in doucmentations 2013-07-25 12:34:15 +02:00
sysrq.txt sysrq: Allow magic SysRq key functions to be disabled through Kconfig 2013-10-16 13:01:44 -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 vfio: fix documentation 2013-09-05 16:36:21 -06:00
vgaarbiter.txt
video-output.txt
vme_api.txt
volatile-considered-harmful.txt
workqueue.txt workqueue: Correct/Drop references to gcwq in Documentation 2013-08-21 10:32:09 -04:00
ww-mutex-design.txt mutex: Add support for wound/wait style locks 2013-06-26 12:10:56 +02:00
xz.txt
zorro.txt