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Eric Dumazet 3b098e2d7c net: Consistent skb timestamping 
With RPS inclusion, skb timestamping is not consistent in RX path.

If netif_receive_skb() is used, its deferred after RPS dispatch.

If netif_rx() is used, its done before RPS dispatch.

This can give strange tcpdump timestamps results.

I think timestamping should be done as soon as possible in the receive
path, to get meaningful values (ie timestamps taken at the time packet
was delivered by NIC driver to our stack), even if NAPI already can
defer timestamping a bit (RPS can help to reduce the gap)

Tom Herbert prefer to sample timestamps after RPS dispatch. In case
sampling is expensive (HPET/acpi_pm on x86), this makes sense.

Let admins switch from one mode to another, using a new
sysctl, /proc/sys/net/core/netdev_tstamp_prequeue

Its default value (1), means timestamps are taken as soon as possible,
before backlog queueing, giving accurate timestamps.

Setting a 0 value permits to sample timestamps when processing backlog,
after RPS dispatch, to lower the load of the pre-RPS cpu.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-05-15 23:57:10 -07:00
..
ABI Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 into merge 2010-04-08 13:34:54 -04:00
accounting Documentation/: fix warnings from -Wmissing-prototypes in HOSTCFLAGS 2009-09-23 07:39:28 -07:00
acpi ACPI: support customizing ACPI control methods at runtime 2009-12-11 01:50:08 -05:00
aoe
arm Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-03-12 16:04:50 -08:00
auxdisplay includecheck fix: Documentation, cfag12864b-example.c 2009-09-24 07:20:57 -07:00
blackfin Blackfin: add an example showing how to use the gptimers API 2009-12-15 00:15:04 -05:00
block Documentation: fix block/biodoc.txt dma mapping description 2010-03-08 09:11:07 +01:00
blockdev The DRBD driver 2009-10-01 21:17:49 +02:00
cdrom ide: doc: remove compilation options section from ide-cd documentation 2009-12-13 20:41:53 -08:00
cgroups cgroups: fix procs documentation 2010-04-24 11:31:25 -07:00
connector include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
console doc: fix console doc typo 2010-02-24 13:51:32 +01:00
cpu-freq [CPUFREQ] Processor Clocking Control interface driver 2010-01-13 10:55:16 -05:00
cpuidle
cris
crypto async_tx: add support for asynchronous RAID6 recovery operations 2009-08-29 19:09:27 -07:00
development-process docs: Encourage better changelogs in the development process document 2009-06-04 10:32:49 -06:00
device-mapper dm: document when snapshot has finished merging 2010-03-06 02:29:56 +00:00
DocBook libata: Fix several inaccuracies in developer's guide 2010-05-05 14:48:27 -04:00
driver-model Fix spelling of 'platform' in comments and doc 2010-02-05 12:22:34 +01:00
dvb V4L/DVB: get_dvb_firmware: Fix typo, sort list of components 2010-02-26 15:10:56 -03:00
early-userspace
fault-injection lkdtm: add debugfs access and loosen KPROBE ties 2010-03-06 11:26:32 -08:00
fb fbdev: rename imacfb.txt to efifb.txt and change imacfb to efifb. 2010-04-07 08:38:02 -07:00
filesystems revert "procfs: provide stack information for threads" and its fixup commits 2010-05-11 17:33:41 -07:00
firmware_class driver core: fix documentation of request_firmware_nowait 2009-06-15 21:30:24 -07:00
frv
hwmon Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
i2c i2c-core: Erase pointer to clientdata on removal 2010-05-04 11:09:27 +02:00
i2o
ia64 Documentation/: fix warnings from -Wmissing-prototypes in HOSTCFLAGS 2009-09-23 07:39:28 -07:00
ide ide: preserve Host Protected Area by default (v2) 2009-06-07 13:52:52 +02:00
infiniband IB: Fix typo in ipoib.txt 2009-12-09 14:21:36 -08:00
input Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2010-05-05 07:53:18 -07:00
ioctl Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2010-03-19 09:43:06 -07:00
isdn gigaset: small documentation improvement 2010-02-26 01:24:22 -08:00
ja_JP block: rename CONFIG_LBD to CONFIG_LBDAF 2009-06-19 08:08:50 +02:00
kbuild kbuild: generate modules.builtin 2009-12-12 13:08:16 +01:00
kdump trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
ko_KR
kvm KVM: trivial document fixes 2010-03-01 12:35:43 -03:00
laptops Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2010-03-12 16:04:50 -08:00
lguest lguest: remove unneeded zlib.h include in example launcher 2010-02-24 14:22:22 +10:30
m68k
make
mips
misc-devices ad525x_dpot: new driver for AD525x digital potentiometers 2009-12-15 08:53:25 -08:00
mn10300 trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
mtd trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
namespaces
netlabel
networking net: reserve ports for applications using fixed port numbers 2010-05-15 23:28:40 -07:00
parisc
PCI Documentation: rename PCI/PCI-DMA-mapping.txt to DMA-API-HOWTO.txt 2010-03-24 16:31:20 -07:00
pcmcia pcmcia: use ops_mutex for rsrc_{mgr,nonstatic} locking 2010-02-17 17:48:24 +01:00
power Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
powerpc powerpc/fsl: add device tree binding for QE firmware 2010-03-26 22:09:57 -06:00
pps LinuxPPS: core support 2009-06-18 13:04:04 -07:00
prctl
RCU rcu: Update docs for rcu_access_pointer and rcu_dereference_protected 2010-04-14 12:20:12 +02:00
s390 Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
scheduler sched: Documentation/sched-rt-group: Fix style issues & bump version 2009-06-21 13:12:46 +02:00
scsi Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
serial ldisc: new dcd_change() method for line disciplines 2010-03-12 15:52:43 -08:00
sh
sound ALSA: hda - Update document about MSI and interrupts 2010-04-01 18:08:29 +02:00
sparc
spi spi: spidev_test gives error upon 1-byte transfer 2010-04-29 16:40:30 -06:00
sysctl net: Consistent skb timestamping 2010-05-15 23:57:10 -07:00
telephony
thermal thermal: add sanity check for the passive attribute 2009-11-05 18:18:10 -05:00
timers Documentation/timers/: split txt and source files 2010-03-12 15:52:35 -08:00
trace Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
uml
usb USB: convert to the runtime PM framework 2010-03-02 14:54:12 -08:00
video4linux V4L/DVB: Documentation: gspca.txt: update known mr97310a cams 2010-02-26 15:11:09 -03:00
vm Documentation/vm/: split txt and source files 2010-03-12 15:52:35 -08:00
w1 ds2482: Discard obsolete detect method 2009-10-04 22:53:41 +02:00
watchdog [WATCHDOG] doc: Fix use of WDIOC_SETOPTIONS ioctl. 2010-04-06 14:23:55 +00:00
wimax
x86 x86, numa: Remove configurable node size support for numa emulation 2010-02-15 14:34:18 -08:00
zh_CN
00-INDEX Bluetooth: Add documentation for Marvell Bluetooth driver 2009-08-22 14:25:32 -07:00
applying-patches.txt
atomic_ops.txt Documentation/atomic_ops.txt: fix sample code 2009-06-16 19:47:52 -07:00
bad_memory.txt
basic_profiling.txt
binfmt_misc.txt
braille-console.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
bt8xxgpio.txt
btmrvl.txt Bluetooth: Add documentation for Marvell Bluetooth driver 2009-08-22 14:25:32 -07:00
BUG-HUNTING
cachetlb.txt Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm 2010-03-01 09:15:15 -08:00
Changes netfilter: xtables: remove xt_string revision 0 2010-03-25 17:04:57 +01:00
circular-buffers.txt Document Linux's circular buffering capabilities 2010-03-24 16:31:22 -07:00
CodingStyle trivial: fix typo milisecond/millisecond for documentation and source comments. 2009-06-12 18:01:46 +02:00
cpu-hotplug.txt cpumask: don't recommend set_cpus_allowed hack in Documentation/cpu-hotplug.txt 2009-12-17 11:43:29 +10:30
cpu-load.txt
cputopology.txt Documentation: ABI: /sys/devices/system/cpu/cpu#/ topology files 2009-10-30 14:59:52 -07:00
credentials.txt
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 trivial: Documentation/dell_rbu.txt: fix typos 2009-06-12 18:01:50 +02:00
devices.txt lanana: assign a device name and numbering for MAX3100 2009-04-07 08:44:05 -07:00
DMA-API-HOWTO.txt Documentation: rename PCI/PCI-DMA-mapping.txt to DMA-API-HOWTO.txt 2010-03-24 16:31:20 -07:00
DMA-API.txt Documentation: rename PCI-DMA-mapping.txt to DMA-API-HOWTO.txt 2010-03-12 15:52:43 -08:00
DMA-attributes.txt
DMA-ISA-LPC.txt
dmaengine.txt
dontdiff Merge branch 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-kconfig 2010-02-25 14:43:57 -08:00
dynamic-debug-howto.txt Dynamic debug: allow simple quoting of words 2009-03-24 16:38:27 -07:00
edac.txt fix typos/grammos in Documentation/edac.txt 2009-12-04 15:39:53 +01:00
eisa.txt doc: fix Defaultd -> Defaults typo in EISA doc 2010-02-05 12:22:39 +01:00
email-clients.txt Documentation/email-clients.txt: update gmail information 2010-03-12 15:52:35 -08:00
feature-removal-schedule.txt Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 2010-05-12 00:05:35 -07:00
flexible-arrays.txt Update flex_arrays.txt 2009-10-15 07:25:20 -06:00
futex-requeue-pi.txt futex: add requeue-pi documentation 2009-05-09 07:12:50 +02:00
gcov.txt trivial: fix typo in CONFIG_DEBUG_FS in gcov doc 2009-09-21 15:14:56 +02:00
gpio.txt gpio: introduce gpio_request_one() and friends 2010-03-06 11:26:48 -08:00
highuid.txt
HOWTO Documentation/HOWTO: update git home URL 2010-04-22 15:24:56 -07:00
hw_random.txt
init.txt init/main.c: improve usability in case of init binary failure 2010-03-06 11:26:29 -08:00
initrd.txt
Intel-IOMMU.txt intel-iommu: Kill DMAR_BROKEN_GFX_WA option. 2009-09-19 09:37:23 -07:00
intel_txt.txt x86, intel_txt: Intel TXT boot support 2009-07-21 11:49:06 -07:00
io-mapping.txt
IO-mapping.txt Documentation: fix ioremap return type 2010-01-02 10:09:44 -08:00
io_ordering.txt
iostats.txt
IPMI.txt ipmi: add parameter to limit CPU usage in kipmid 2010-03-12 15:52:39 -08:00
IRQ-affinity.txt
IRQ.txt
irqflags-tracing.txt
isapnp.txt
java.txt
kernel-doc-nano-HOWTO.txt documentation: update kernel-doc-nano-HOWTO information 2010-01-11 09:34:07 -08:00
kernel-docs.txt
kernel-parameters.txt libata: fix docs, RE port and device of libata.force ID separated by point 2010-04-22 21:52:14 -04:00
keys-request-key.txt
keys.txt KEYS: Add a keyctl to install a process's session keyring on its parent [try #6] 2009-09-02 21:29:22 +10:00
kmemcheck.txt kmemcheck: update documentation 2009-07-01 22:36:22 +02:00
kmemleak.txt kmemleak: add clear command support 2009-09-08 16:36:08 +01:00
kobject.txt kobject: documentation: Update to refer to kset-example.c. 2010-03-19 07:12:20 -07:00
kprobes.txt kprobes: Add documents of jump optimization 2010-02-25 17:49:27 +01:00
kref.txt kref: double kref_put() in my_data_handler() 2009-09-18 09:48:52 -07:00
ldm.txt
leds-class.txt led: document sysfs interface 2009-08-28 15:21:12 -04:00
leds-lp3944.txt leds: LED driver for National Semiconductor LP3944 Funlight Chip 2009-06-23 20:21:38 +01:00
local_ops.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
lockdep-design.txt lockdep: Fix typos in documentation 2009-08-07 12:03:46 +02:00
lockstat.txt lockstat: Add usage info to Documentation/lockstat.txt 2009-12-06 13:20:02 +01:00
logo.gif Revert "linux.conf.au 2009: Tuz" 2009-04-27 12:00:27 -07:00
logo.txt Revert "linux.conf.au 2009: Tuz" 2009-04-27 12:00:27 -07:00
magic-number.txt
Makefile Documentation/fs/: split txt and source files 2010-03-12 15:52:35 -08:00
ManagementStyle
mca.txt
md.txt md: add 'recovery_start' per-device sysfs attribute 2009-12-14 12:58:57 +11:00
memory-barriers.txt Document Linux's circular buffering capabilities 2010-03-24 16:31:22 -07:00
memory-hotplug.txt mm: add numa node symlink for memory section in sysfs 2009-12-15 08:53:17 -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
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 docs: Describe the 'C' taint flag in oops-tracing.txt 2009-11-09 09:40:56 +01:00
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
prio_tree.txt
rbtree.txt trivial: rbtree.txt: fix rb_entry() parameters in sample code 2009-06-12 18:01:47 +02:00
rfkill.txt Document the rfkill sysfs ABI 2010-03-10 17:09:33 -05:00
robust-futex-ABI.txt futex: documentation: fix inconsistent description of futex list_op_pending 2009-06-18 13:03:56 -07:00
robust-futexes.txt
rt-mutex-design.txt
rt-mutex.txt
rtc.txt rtc: add boot_timesource sysfs attribute 2009-09-23 07:39:46 -07:00
SAK.txt
SecurityBugs
SELinux.txt
serial-console.txt
sgi-ioc4.txt
sgi-visws.txt
slow-work.txt SLOW_WORK: Move slow_work's proc file to debugfs 2009-12-01 08:20:31 -08:00
SM501.txt trivial: Miscellaneous documentation typo fixes 2009-06-12 18:01:47 +02:00
Smack.txt smack: implement logging V3 2009-04-14 09:00:23 +10:00
sparse.txt Documentation: explain the difference between __bitwise and __bitwise__ 2009-04-11 08:18:11 +02:00
spinlocks.txt Documentation: rw_lock lessons learned 2009-12-14 09:46:56 -08:00
stable_api_nonsense.txt
stable_kernel_rules.txt Documentation: -stable rules: upstream commit ID requirement reworded 2010-04-22 15:24:56 -07:00
SubmitChecklist Documentation/SubmitChecklist: add rule #1 2010-03-12 15:52:35 -08:00
SubmittingDrivers
SubmittingPatches docs: update patch size in SubmittingPatches 2009-10-01 16:11:12 -07:00
svga.txt
sysfs-rules.txt Doc/sysfs-rules: Swap the order of the words so the sentence makes more sense 2009-05-08 19:22:20 -07:00
sysrq.txt sysrq, kdump: make sysrq-c consistent 2009-07-29 19:10:36 -07:00
tomoyo.txt tomoyo: add Documentation/tomoyo.txt 2009-04-14 09:14:58 +10:00
unaligned-memory-access.txt
unicode.txt
unshare.txt
VGA-softcursor.txt
vgaarbiter.txt vgaarbiter: fix a typo in the vgaarbiter Documentation 2009-12-16 11:28:58 -08:00
video-output.txt
volatile-considered-harmful.txt Documentation/volatile-considered-harmful.txt: correct cpu_relax() documentation 2010-03-24 16:31:20 -07:00
zorro.txt