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Eric Dumazet f1aadd5858 tcp: change tcp_adv_win_scale and tcp_rmem[2] 
[ Upstream commit b49960a05e ]

tcp_adv_win_scale default value is 2, meaning we expect a good citizen
skb to have skb->len / skb->truesize ratio of 75% (3/4)

In 2.6 kernels we (mis)accounted for typical MSS=1460 frame :
1536 + 64 + 256 = 1856 'estimated truesize', and 1856 * 3/4 = 1392.
So these skbs were considered as not bloated.

With recent truesize fixes, a typical MSS=1460 frame truesize is now the
more precise :
2048 + 256 = 2304. But 2304 * 3/4 = 1728.
So these skb are not good citizen anymore, because 1460 < 1728

(GRO can escape this problem because it build skbs with a too low
truesize.)

This also means tcp advertises a too optimistic window for a given
allocated rcvspace : When receiving frames, sk_rmem_alloc can hit
sk_rcvbuf limit and we call tcp_prune_queue()/tcp_collapse() too often,
especially when application is slow to drain its receive queue or in
case of losses (netperf is fast, scp is slow). This is a major latency
source.

We should adjust the len/truesize ratio to 50% instead of 75%

This patch :

1) changes tcp_adv_win_scale default to 1 instead of 2

2) increase tcp_rmem[2] limit from 4MB to 6MB to take into account
better truesize tracking and to allow autotuning tcp receive window to
reach same value than before. Note that same amount of kernel memory is
consumed compared to 2.6 kernels.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: 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>
2012-05-21 09:40:00 -07:00
..
ABI backlight: new driver for the ADP8870 backlight devices 2011-06-15 20:03:59 -07:00
accounting Documentation: update cgroupfs mount point 2011-06-15 21:52:50 -07:00
acpi ACPI: Split out custom_method functionality into an own driver 2011-05-29 01:50:40 -04:00
aoe Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
arm Merge branch 'for-rmk' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into devel-stable 2011-05-25 21:47:48 +01:00
auxdisplay includecheck fix: Documentation, cfag12864b-example.c 2009-09-24 07:20:57 -07:00
blackfin Blackfin: document SPI CS limitations with CPHA=0 2010-08-06 12:55:52 -04:00
block Fix common misspellings 2011-03-31 11:26:23 -03:00
blockdev cciss: add cciss_tape_cmds module paramter 2011-05-06 08:23:59 -06:00
cdrom Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
cgroups Documentation: fix cgroup blkio throttle filenames 2011-07-06 13:17:51 -07:00
connector Documentation/: it's -> its where appropriate 2010-04-23 02:09:52 +02:00
console doc: fix console doc typo 2010-02-24 13:51:32 +01:00
cpu-freq [CPUFREQ] Add documentation for sampling_down_factor 2011-03-16 17:54:31 -04:00
cpuidle
cris
crypto async_tx: add support for asynchronous RAID6 recovery operations 2009-08-29 19:09:27 -07:00
development-process Documentation: Update stable address 2012-01-12 11:34:54 -08:00
device-mapper Fix common misspellings 2011-03-31 11:26:23 -03:00
devicetree Merge branches 'devel', 'devel-stable' and 'fixes' into for-linus 2011-05-27 22:59:57 +01:00
DocBook Merge git://git.infradead.org/mtd-2.6 2011-05-27 20:06:53 -07:00
driver-model driver core: remove the driver-model structures from the documentation 2011-05-06 18:01:05 -07:00
dvb Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
early-userspace
fault-injection lkdtm: add debugfs access and loosen KPROBE ties 2010-03-06 11:26:32 -08:00
fb Fix common misspellings 2011-03-31 11:26:23 -03:00
filesystems nilfs2: remove resize from unsupported features list 2011-07-13 16:08:59 +09:00
firmware_class firmware: Update hotplug script 2010-08-05 13:53:34 -07:00
frv
hid HID: Move hiddev.txt to the new Documentation/hid directory 2011-03-22 11:43:51 +01:00
hwmon hwmon: (jc42) Add support for AT30TS00, TS3000GB2, TSE2002GB2, and MCP9804 2012-03-12 10:33:00 -07:00
i2c i2c-i801: SMBus patch for Intel Panther Point DeviceIDs 2011-05-24 20:58:49 +02:00
i2o Fix common misspellings 2011-03-31 11:26:23 -03:00
ia64 Fix common misspellings 2011-03-31 11:26:23 -03:00
ide
infiniband Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
input Input: elantech - describe further the protocol 2011-05-16 22:48:24 -07:00
ioctl Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc 2011-05-25 16:55:55 -07:00
isdn Fix common misspellings 2011-03-31 11:26:23 -03:00
ja_JP HOWTO: sync up Documentaion/ja_JP/HOWTO 2011-04-19 16:53:45 -07:00
kbuild Merge branch 'kconfig-for-40' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6 2011-05-25 16:54:01 -07:00
kdump kdump: update kexec-tools URL and Vivek's email 2010-11-25 14:36:38 +01:00
ko_KR Docs/Kconfig: Update: osdl.org -> linuxfoundation.org 2010-11-15 23:50:13 +01:00
laptops thinkpad-acpi: handle HKEY 0x4010, 0x4011 events 2011-07-07 10:39:05 -04:00
leds Documentation: consolidate leds files to leds/ subdir 2011-04-04 17:51:47 -07:00
m68k
make kbuild: introduce HDR_ARCH_LIST for headers_install_all 2010-12-14 22:16:19 +01:00
mips Fix common misspellings 2011-03-31 11:26:23 -03:00
misc-devices Fix common misspellings 2011-03-31 11:26:23 -03:00
mmc mmc: MMC boot partitions support. 2011-05-24 21:01:21 -04:00
mn10300
mtd Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
namespaces
netlabel Documentation/: it's -> its where appropriate 2010-04-23 02:09:52 +02:00
networking tcp: change tcp_adv_win_scale and tcp_rmem[2] 2012-05-21 09:40:00 -07:00
nfc NFC: Driver for NXP Semiconductors PN544 NFC chip. 2011-01-13 08:03:19 -08:00
parisc
PCI Fix common misspellings 2011-03-31 11:26:23 -03:00
pcmcia pcmcia: use autoconfiguration feature for ioports and iomem 2010-09-29 17:20:24 +02:00
power PM / Runtime: Automatically retry failed autosuspends 2011-11-11 09:36:57 -08:00
powerpc Fix common misspellings 2011-03-31 11:26:23 -03:00
pps pps: add parallel port PPS signal generator 2011-01-13 08:03:21 -08:00
prctl
pti Kernel documentation for the PTI feature. 2011-05-13 16:31:00 -07:00
ptp ptp: Added a brand new class driver for ptp clocks. 2011-05-23 13:01:00 -07:00
rapidio rapidio: add RapidIO documentation 2011-03-23 19:46:41 -07:00
RCU rcu: Decrease memory-barrier usage based on semi-formal proof 2011-05-26 09:42:23 -07:00
s390 Documentation: fix minor typos/spelling 2011-04-04 17:51:47 -07:00
scheduler Documentation: update cgroupfs mount point 2011-06-15 21:52:50 -07:00
scsi [SCSI] megaraid_sas: Version and Changelog update 2011-05-24 12:36:06 -04:00
security Create Documentation/security/, 2011-05-19 15:59:38 -07:00
serial Fix common misspellings 2011-03-31 11:26:23 -03:00
sh sh: clkfwk: Kill off unused clk_set_rate_ex(). 2010-11-15 18:25:12 +09:00
sound Merge branch 'topic/hda' into for-linus 2011-05-22 10:01:35 +02:00
sparc
spi Fix common misspellings 2011-03-31 11:26:23 -03:00
sysctl coredump: add support for exe_file in core name 2011-05-26 17:12:36 -07:00
target [SCSI] tcm_mod_builder.py: Fix generated *_drop_nodeacl() handler 2011-03-23 11:36:45 -05:00
telephony Fix common misspellings 2011-03-31 11:26:23 -03:00
thermal thermal: Add event notification to thermal framework 2011-01-12 00:08:35 -05:00
timers doc: timers-howto: fix a typo ("unsgined") 2011-05-17 10:52:02 +02:00
trace sched: Get rid of lock_depth 2011-04-24 13:18:38 +02:00
usb USB: update documentation for usbmon 2012-01-12 11:35:06 -08:00
video4linux [media] uvcvideo: Add driver documentation 2011-05-20 09:30:36 -03:00
virtual lguest: allow booting guest with CONFIG_RELOCATABLE=y 2011-08-17 10:55:53 -07:00
vm Documentation: update cgroupfs mount point 2011-06-15 21:52:50 -07:00
w1 Fix common misspellings 2011-03-31 11:26:23 -03:00
watchdog Fix common misspellings 2011-03-31 11:26:23 -03:00
wimax
x86 x86, doc only: Correct real-mode kernel header offset for init_size 2011-07-12 20:39:11 -07:00
zh_CN Translated Documentation/email-clients.txt 2011-05-06 17:59:20 -07:00
.gitignore add random binaries to .gitignore 2010-04-08 11:34:34 +02:00
00-INDEX Merge branch 'docs-security' into docs-move 2011-05-20 09:10:04 -07:00
applying-patches.txt
atomic_ops.txt Documentation/atomic_ops.txt: avoid volatile in sample code 2011-05-26 17:12:34 -07:00
bad_memory.txt
basic_profiling.txt
binfmt_misc.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
braille-console.txt
bt8xxgpio.txt
btmrvl.txt Bluetooth: Add documentation for Marvell Bluetooth driver 2009-08-22 14:25:32 -07:00
BUG-HUNTING
bus-virt-phys-mapping.txt documentation: fix almost duplicate filenames (IO/io-mapping.txt) 2010-07-20 17:49:30 +00:00
cachetlb.txt mm: convert mm->cpu_vm_cpumask into cpumask_var_t 2011-05-25 08:39:21 -07:00
Changes Documentation/Changes: remove some really obsolete text 2011-07-11 16:48:38 -07:00
circular-buffers.txt Document Linux's circular buffering capabilities 2010-03-24 16:31:22 -07:00
coccinelle.txt scripts/coccinelle: update for compatability with Coccinelle 0.2.4 2010-12-03 12:27:01 +01:00
CodingStyle Documentation: update CodingStyle memory allocators 2011-07-06 13:17:51 -07:00
cpu-hotplug.txt Fix common misspellings 2011-03-31 11:26:23 -03:00
cpu-load.txt
cputopology.txt topology/sysfs: Provide book id and siblings attributes 2010-09-09 20:41:25 +02:00
dcdbas.txt
debugging-modules.txt
debugging-via-ohci1394.txt ieee1394: update URLs in debugging-via-ohci1394.txt 2009-10-03 09:28:11 +02:00
dell_rbu.txt Fix common misspellings 2011-03-31 11:26:23 -03:00
devices.txt Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 2010-10-28 09:35:11 -07:00
DMA-API-HOWTO.txt Documentation: DMA-API-HOWTO.txt: rename ARCH_KMALLOC_MINALIGN to ARCH_DMA_MINALIGN 2010-08-14 11:56:46 -07:00
DMA-API.txt dma-mapping: remove dma_is_consistent API 2010-08-11 08:59:21 -07:00
DMA-attributes.txt
DMA-ISA-LPC.txt
dmaengine.txt dmaengine: Add API documentation for slave dma usage 2011-05-25 14:49:20 -07:00
dontdiff Documentation: update dontdiff file 2011-05-23 15:14:11 -07:00
dynamic-debug-howto.txt Merge branch 'docs-next' of git://git.lwn.net/linux-2.6 2011-03-27 19:46:59 -07:00
edac.txt Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
eisa.txt Fix common misspellings 2011-03-31 11:26:23 -03:00
email-clients.txt Documentation/email-clients.txt: update Thunderbird docs with wordwrap plugin 2011-01-13 08:03:15 -08:00
feature-removal-schedule.txt Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 2011-07-11 16:43:27 -07:00
flexible-arrays.txt flex_array: flex_array_prealloc takes a number of elements, not an end 2011-04-28 16:12:47 -04:00
futex-requeue-pi.txt
gcov.txt trivial: fix typo in CONFIG_DEBUG_FS in gcov doc 2009-09-21 15:14:56 +02:00
gpio.txt Revert "gpiolib: annotate gpio-intialization with __must_check" 2011-01-13 17:26:46 -08:00
highuid.txt
HOWTO Documentation: Update stable address 2012-01-12 11:34:54 -08:00
hw_random.txt
hwspinlock.txt hwspinlock/core: use a mutex to protect the radix tree 2011-11-11 09:36:31 -08:00
init.txt init/main.c: improve usability in case of init binary failure 2010-03-06 11:26:29 -08:00
initrd.txt
intel_txt.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
Intel-IOMMU.txt intel-iommu: Kill DMAR_BROKEN_GFX_WA option. 2009-09-19 09:37:23 -07:00
io_ordering.txt
io-mapping.txt
iostats.txt Documentation/iostats.txt: bit-size reference etc. 2011-03-23 20:44:18 +01:00
IPMI.txt IPMI: Add the document description of ipmi_get_smi_info 2010-12-14 00:22:00 -05:00
IRQ-affinity.txt bitmap, irq: add smp_affinity_list interface to /proc/irq 2011-05-25 08:39:45 -07:00
IRQ.txt
irqflags-tracing.txt Fix common misspellings 2011-03-31 11:26:23 -03:00
isapnp.txt
java.txt
kernel-doc-nano-HOWTO.txt docbook: warn on unused doc entries 2010-09-11 16:49:21 -07:00
kernel-docs.txt Documentation: update kernel-docs.txt 2011-01-06 09:59:38 -08:00
kernel-parameters.txt PCI: conditional resource-reallocation through kernel parameter pci=realloc 2011-07-08 15:49:20 -07:00
kmemcheck.txt kmemcheck: update documentation 2009-07-01 22:36:22 +02:00
kmemleak.txt Documentation: update kmemleak supported archs 2011-06-15 21:52:50 -07:00
kobject.txt kobject: documentation: Update to refer to kset-example.c. 2010-03-19 07:12:20 -07:00
kprobes.txt tree-wide: fix comment/printk typos 2010-11-01 15:38:34 -04:00
kref.txt kref: Fix typo in kref documentation 2011-03-07 13:20:05 -08:00
ldm.txt Documentation: update broken web addresses. 2010-08-04 15:21:40 +02:00
local_ops.txt
lockdep-design.txt lockdep: Fix typos in documentation 2009-08-07 12:03:46 +02:00
lockstat.txt Documentation: Add statistics about nested locks 2011-05-28 17:03:29 +02:00
logo.gif
logo.txt
magic-number.txt take coda-private headers out of include/linux 2011-01-12 20:02:48 -05:00
Makefile [media] Remove the old V4L1 v4lgrab.c file 2010-12-29 08:17:12 -02:00
ManagementStyle
mca.txt
md.txt md:Documentation/md.txt - fix typo 2011-06-09 11:43:04 +10:00
media-framework.txt Fix common misspellings 2011-03-31 11:26:23 -03:00
memory-barriers.txt smp: Document transitivity for memory barriers. 2011-03-04 08:05:49 -08:00
memory-hotplug.txt memory hotplug: Allow memory blocks to span multiple memory sections 2011-02-03 16:08:57 -08:00
memory.txt Documentation/memory.txt: remove some very outdated recommendations 2009-09-22 07:17:26 -07:00
mono.txt
mutex-design.txt mutex: Fix annotations to include it in kernel-locking docbook 2010-09-03 08:19:51 +02:00
nmi_watchdog.txt
nommu-mmap.txt nommu: fix malloc performance by adding uninitialized flag 2009-12-15 08:53:24 -08:00
numastat.txt mm: fix NUMA accounting in numastat.txt 2009-09-22 07:17:39 -07:00
oops-tracing.txt panic: Add taint flag TAINT_FIRMWARE_WORKAROUND ('I') 2010-05-19 08:37:43 +01:00
padata.txt Documentation/padata.txt: fix typos etc. 2010-08-11 08:59:18 -07:00
parport-lowlevel.txt
parport.txt
pi-futex.txt
pnp.txt doc: capitalization and other minor fixes in pnp doc 2010-02-05 12:22:44 +01:00
preempt-locking.txt
printk-formats.txt Documentation: update printk-formats.txt 2011-06-15 21:52:50 -07:00
prio_tree.txt
rbtree.txt Documentation: remove anticipatory scheduler info 2010-11-11 12:09:59 +01:00
rfkill.txt Document the rfkill sysfs ABI 2010-03-10 17:09:33 -05:00
robust-futex-ABI.txt
robust-futexes.txt
rt-mutex-design.txt variable name fix to Documentation/rt-mutex-design.txt 2010-06-05 17:39:09 +02:00
rt-mutex.txt
rtc.txt RTC: Fix up rtc.txt documentation to reflect changes to generic rtc layer 2011-03-09 11:25:10 -08:00
SAK.txt
SecurityBugs Fix common misspellings 2011-03-31 11:26:23 -03:00
serial-console.txt
sgi-ioc4.txt
sgi-visws.txt
SM501.txt
sparse.txt update email address 2010-07-19 10:56:54 +02:00
spinlocks.txt Documentation/spinlocks.txt: Remove reference to sti()/cli() 2011-07-11 12:45:04 -07:00
stable_api_nonsense.txt doc: stable_api_nonsense.txt: fix paragraph to make more sense. 2011-03-30 12:02:05 +02:00
stable_kernel_rules.txt Update email address for stable patch submission 2011-11-11 09:35:46 -08:00
SubmitChecklist Documentation: update SubmitChecklist for O=objdir and kconfig testing 2010-05-24 07:31:20 -07:00
SubmittingDrivers Fix common misspellings 2011-03-31 11:26:23 -03:00
SubmittingPatches Documentation: update GregKH links 2011-05-23 15:14:11 -07:00
svga.txt
sysfs-rules.txt Fix typos in comments 2010-03-16 11:47:56 +01:00
sysrq.txt documentation: update sysrq.txt magic sysrq keys 2010-10-26 17:32:41 -07:00
unaligned-memory-access.txt
unicode.txt
unshare.txt
VGA-softcursor.txt
vgaarbiter.txt Documentation: fix vgaarbiter.txt typos etc. 2011-05-23 15:14:11 -07:00
video-output.txt
volatile-considered-harmful.txt Documentation/volatile-considered-harmful.txt: correct cpu_relax() documentation 2010-03-24 16:31:20 -07:00
workqueue.txt workqueue: Document debugging tricks 2011-03-31 13:40:42 +02:00
xz.txt decompressors: add XZ decompressor module 2011-01-13 08:03:24 -08:00
zorro.txt