Commit graph

12,669 commits

Author SHA1 Message Date
Ingo Molnar
09b22a2f67 Merge commit 'v2.6.27-rc6' into sched/devel 2008-09-11 13:37:28 +02:00
Eric Miao
4d5975e501 Input: ads7846 - introduce .gpio_pendown to get pendown state
The GPIO connected to ADS7846 nPENIRQ signal is usually used to get
the pendown state as well. Introduce a .gpio_pendown, and use this
to decide the pendown state if .get_pendown_state is NULL.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2008-09-10 12:13:28 -04:00
Ingo Molnar
3ce9bcb583 Merge branch 'core/xen' into x86/xen 2008-09-10 14:05:45 +02:00
Jeremy Fitzhardinge
f7d0b926ac mm: define USE_SPLIT_PTLOCKS rather than repeating expression
Define USE_SPLIT_PTLOCKS as a constant expression rather than repeating
"NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS" all over the place.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-10 14:04:59 +02:00
Ingo Molnar
59c37bf892 Merge commit 'v2.6.27-rc6' into x86/unify-cpu-detect
Conflicts:
	arch/x86/kernel/cpu/amd.c
	arch/x86/kernel/cpu/common.c
	arch/x86/kernel/cpu/common_64.c
	arch/x86/kernel/cpu/feature_names.c
	include/asm-x86/cpufeature.h

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-10 14:00:45 +02:00
FUJITA Tomonori
636dc67cbf add is_buffer_dma_capable helper function
is_buffer_dma_capable helper function is to see if a memory region is
DMA-capable or not. The arugments are the dma_mask (or
coherent_dma_mask) of a device and the address and size of a memory
region.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-10 11:33:43 +02:00
Ingo Molnar
e92b4fdacc Merge commit 'v2.6.27-rc6' into x86/iommu 2008-09-10 11:32:52 +02:00
Ingo Molnar
429b022af4 Merge commit 'v2.6.27-rc6' into core/rcu 2008-09-10 08:35:40 +02:00
Marc Zyngier
fb683f1627 Export smc91x led definitions
Now that we can configure smc91x leds from its platform data,
it seems rather useful to move the led definitions to the
externally visible header file.

Signed-off-by: Marc Zyngier <marc.zyngier@altran.com>
2008-09-09 17:41:42 +02:00
Gerrit Renker
410e27a49b This reverts "Merge branch 'dccp' of git://eden-feed.erg.abdn.ac.uk/dccp_exp"
as it accentally contained the wrong set of patches. These will be
submitted separately.
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-09 13:27:22 +02:00
David S. Miller
0a68a20cc3 Merge branch 'dccp' of git://eden-feed.erg.abdn.ac.uk/dccp_exp
Conflicts:

	net/dccp/input.c
	net/dccp/options.c
2008-09-08 17:28:59 -07:00
David S. Miller
17dce5dfe3 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6
Conflicts:

	net/mac80211/mlme.c
2008-09-08 16:59:05 -07:00
Linus Torvalds
e1d7bf1499 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: arch_reinit_sched_domains() must destroy domains to force rebuild
  sched, cpuset: rework sched domains and CPU hotplug handling (v4)
2008-09-08 15:47:21 -07:00
Jeremy Fitzhardinge
9c3254ad42 x86: fix compile error with corruption checking disabled
Fix compile error:

 arch/x86/mm/init_32.c: In function 'mem_init':
 arch/x86/mm/init_32.c:908: error: implicit declaration of function 'start_periodic_check_for_corruption'

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-08 20:03:06 +02:00
Manfred Spraul
e545a6140b kernel/cpu.c: create a CPU_STARTING cpu_chain notifier
Right now, there is no notifier that is called on a new cpu, before the new
cpu begins processing interrupts/softirqs.
Various kernel function would need that notification, e.g. kvm works around
by calling smp_call_function_single(), rcu polls cpu_online_map.

The patch adds a CPU_STARTING notification. It also adds a helper function
that sends the message to all cpu_chain handlers.

Tested on x86-64.
All other archs are untested. Especially on sparc, I'm not sure if I got
it right.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-08 19:25:24 +02:00
Theodore Ts'o
05496769e5 jbd2: clean up how the journal device name is printed
Calculate the journal device name once and stash it away in the
journal_s structure.  This avoids needing to call bdevname()
everywhere and reduces stack usage by not needing to allocate an
on-stack buffer.  In addition, we eliminate the '/' that can appear in
device names (e.g. "cciss/c0d0p9" --- see kernel bugzilla #11321) that
can cause problems when creating proc directory names, and include the
inode number to support ocfs2 which creates multiple journals with
different inode numbers.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-09-16 14:36:17 -04:00
Russell King
b0dbcf511c [NET] smc91x: provide configurable leds
This patch provides a mechanism for platforms to be able to supply the
LED configuration via platform data, rather than having to hard code
it in smc91x.h.

Acked-by: Eric Miao <eric.y.miao@gmail.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-09-07 17:32:58 +01:00
Hugh Dickins
bb577f980e x86: add periodic corruption check
Perodically check for corruption in low phusical memory.  Don't bother
checking at fault time, since it won't show anything useful.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-07 17:40:00 +02:00
Jeremy Fitzhardinge
5394f80f92 x86: check for and defend against BIOS memory corruption
Some BIOSes have been observed to corrupt memory in the low 64k.  This
change:
 - Reserves all memory which does not have to be in that area, to
   prevent it from being used as general memory by the kernel.  Things
   like the SMP trampoline are still in the memory, however.
 - Clears the reserved memory so we can observe changes to it.
 - Adds a function check_for_bios_corruption() which checks and reports on
   memory becoming unexpectedly non-zero.  Currently it's called in the
   x86 fault handler, and the powermanagement debug output.

Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-07 17:39:59 +02:00
Linus Torvalds
f532522565 Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  clocksource, acpi_pm.c: check for monotonicity
  clocksource, acpi_pm.c: use proper read function also in errata mode
  ntp: fix calculation of the next jiffie to trigger RTC sync
  x86: HPET: read back compare register before reading counter
  x86: HPET fix moronic 32/64bit thinko
  clockevents: broadcast fixup possible waiters
  HPET: make minimum reprogramming delta useful
  clockevents: prevent endless loop lockup
  clockevents: prevent multiple init/shutdown
  clockevents: enforce reprogram in oneshot setup
  clockevents: prevent endless loop in periodic broadcast handler
  clockevents: prevent clockevent event_handler ending up handler_noop
2008-09-06 19:33:26 -07:00
Ingo Molnar
291c54ff76 Merge branch 'sched/cpuset' into sched/urgent 2008-09-06 21:03:16 +02:00
Alexey Dobriyan
978b0116cd softirq: allocate less vectors
We don't need whole 32 of them, only NR_SOFTIRQS.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-06 20:04:36 +02:00
Max Krasnyansky
dfb512ec48 sched: arch_reinit_sched_domains() must destroy domains to force rebuild
What I realized recently is that calling rebuild_sched_domains() in
arch_reinit_sched_domains() by itself is not enough when cpusets are enabled.
partition_sched_domains() code is trying to avoid unnecessary domain rebuilds
and will not actually rebuild anything if new domain masks match the old ones.

What this means is that doing
     echo 1 > /sys/devices/system/cpu/sched_mc_power_savings
on a system with cpusets enabled will not take affect untill something changes
in the cpuset setup (ie new sets created or deleted).

This patch fixes restore correct behaviour where domains must be rebuilt in
order to enable MC powersaving flags.

Test on quad-core Core2 box with both CONFIG_CPUSETS and !CONFIG_CPUSETS.
Also tested on dual-core Core2 laptop. Lockdep is happy and things are working
as expected.

Signed-off-by: Max Krasnyansky <maxk@qualcomm.com>
Tested-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-06 19:22:15 +02:00
Ingo Molnar
7f79d852ed Merge branch 'linus' into sched/devel 2008-09-06 16:51:57 +02:00
Roland McGrath
22f30168d2 tracehook: comment pasto fixes
Fix some pasto's in comments in the new linux/tracehook.h and
asm-generic/syscall.h files.

Reported-by: Wenji Huang <wenji.huang@oracle.com>
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-05 14:39:38 -07:00
Li Zefan
11d55d2cba res_counter: fix off-by-one bug in setting limit
I found we can no longer set limit to 0 with 2.6.27-rcX:
 # mount -t cgroup -omemory xxx /mnt
 # mkdir /mnt/0
 # echo 0 > /mnt/0/memory.limit_in_bytes
 bash: echo: write error: Device or resource busy

It turned out 'limit' can't be set to 'usage', which is wrong IMO.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-05 14:39:37 -07:00
Linus Torvalds
7f621861fb Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: fix process time monotonicity
  sched_clock: fix NOHZ interaction
2008-09-05 14:37:15 -07:00
Linus Torvalds
6f74b1849b Merge git://git.infradead.org/~dwmw2/dwmw2-2.6.27
* git://git.infradead.org/~dwmw2/dwmw2-2.6.27:
  Revert "[ARM] use the new byteorder headers"
  Fix conditional export of kvh.h and a.out.h to userspace.
  [MTD] [NAND] tmio_nand: fix base address programming
2008-09-05 14:31:54 -07:00
Linus Torvalds
14408c4f41 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (98 commits)
  V4L/DVB (8881): gspca: After 'while (retry--) {...}', retry will be -1 but not 0.
  V4L/DVB (8880): PATCH: Fix parents on some webcam drivers
  V4L/DVB (8877): b2c2 and bt8xx: udelay to mdelay
  V4L/DVB (8876): budget: udelay changed to mdelay
  V4L/DVB (8874): gspca: Adjust hstart for sn9c103/ov7630 and update usb-id's.
  V4L/DVB (8873): gspca: Bad image offset with rev012a of spca561 and adjust exposure.
  V4L/DVB (8872): gspca: Bad image format and offset with rev072a of spca561.
  V4L/DVB (8870): gspca: Fix dark room problem with sonixb.
  V4L/DVB (8869): gspca: Move the Sonix webcams with TAS5110C1B from sn9c102 to gspca.
  V4L/DVB (8868): gspca: Support for vga modes with sif sensors in sonixb.
  V4L/DVB (8844): dabusb_fpga_download(): fix a memory leak
  V4L/DVB (8843): tda10048_firmware_upload(): fix a memory leak
  V4L/DVB (8842): vivi_release(): fix use-after-free
  V4L/DVB (8840): dib0700: add basic support for Hauppauge Nova-TD-500 (84xxx)
  V4L/DVB (8839): dib0700: add comment to identify 35th USB id pair
  V4L/DVB (8837): dvb: fix I2C adapters name size
  V4L/DVB (8835): gspca: Same pixfmt as the sn9c102 driver and raw Bayer added in sonixb.
  V4L/DVB (8834): gspca: Have a bigger buffer for sn9c10x compressed images.
  V4L/DVB (8833): gspca: Cleanup the sonixb code.
  V4L/DVB (8832): gspca: Bad pixelformat of vc0321 webcams.
  ...
2008-09-05 14:29:50 -07:00
Linus Torvalds
54e2a3270f Merge branch 'core/debugobjects' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core/debugobjects' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  debugobjects: fix lockdep warning
2008-09-05 14:28:19 -07:00
Luis R. Rodriguez
f59ac04816 cfg80211: keep track of supported interface modes
It is obviously good for userspace to know up front which
interface modes a given piece of hardware might support (even
if adding such an interface might fail later because of
concurrency issues), so let's make cfg80211 aware of that.
For good measure, disallow adding interfaces in all other
modes so drivers don't forget to announce support for one mode
when they add it.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Stephen Blackheath <tramp.enshrine.stephen@blacksapphire.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-09-05 16:17:42 -04:00
Joerg Roedel
ca1af29a73 x86, pci: add northbridge pci ids for fam 0x11 processors
The PCI device ids for AMD family 0x11 processors are missing in pci_ids.h.
This patch adds them.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 19:11:43 +02:00
Balbir Singh
49048622ea sched: fix process time monotonicity
Spencer reported a problem where utime and stime were going negative despite
the fixes in commit b27f03d4bd. The suspected
reason for the problem is that signal_struct maintains it's own utime and
stime (of exited tasks), these are not updated using the new task_utime()
routine, hence sig->utime can go backwards and cause the same problem
to occur (sig->utime, adds tsk->utime and not task_utime()). This patch
fixes the problem

TODO: using max(task->prev_utime, derived utime) works for now, but a more
generic solution is to implement cputime_max() and use the cputime_gt()
function for comparison.

Reported-by: spencer@bluehost.com
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 18:14:35 +02:00
Khem Raj
afbc8d8e72 Fix conditional export of kvh.h and a.out.h to userspace.
Some architectures have moved the asm/ into arch/ and some have not.
This patch checks for a.out.h and kvh.h in both places before exporting
the corresponding file from linux/

[dwmw2: simplified a little]
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-09-05 15:44:31 +01:00
Venkatesh Pallipadi
7c1e768974 clockevents: prevent clockevent event_handler ending up handler_noop
There is a ordering related problem with clockevents code, due to which
clockevents_register_device() called after tickless/highres switch
will not work. The new clockevent ends up with clockevents_handle_noop as
event handler, resulting in no timer activity.

The problematic path seems to be

* old device already has hrtimer_interrupt as the event_handler
* new clockevent device registers with a higher rating
* tick_check_new_device() is called
  * clockevents_exchange_device() gets called
    * old->event_handler is set to clockevents_handle_noop
  * tick_setup_device() is called for the new device
    * which sets new->event_handler using the old->event_handler which is noop.

Change the ordering so that new device inherits the proper handler.

This does not have any issue in normal case as most likely all the clockevent
devices are setup before the highres switch. But, can potentially be affecting
some corner case where HPET force detect happens after the highres switch.
This was a problem with HPET in MSI mode code that we have been experimenting
with.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 11:11:51 +02:00
Ingo Molnar
d3d0ba7b8f Merge commit '63cc8c7515':
"percpu: introduce DEFINE_PER_CPU_PAGE_ALIGNED() macro"

into x86/core

Conflicts:
	arch/x86/kernel/cpu/common.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-05 09:24:30 +02:00
Lennert Buytenhek
ac840605f3 mv643xx_eth: remove force_phy_addr field
Currently, there are two different fields in the
mv643xx_eth_platform_data struct that together describe the PHY
address -- one field (phy_addr) has the address of the PHY, but if
that address is zero, a second field (force_phy_addr) needs to be
set to distinguish the actual address zero from a zero due to not
having filled in the PHY address explicitly (which should mean
'use the default PHY address').

If we are a bit smarter about the encoding of the phy_addr field,
we can avoid the need for a second field -- this patch does that.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
2008-09-05 06:33:59 +02:00
Lennert Buytenhek
fc0eb9f226 mv643xx_eth: smi sharing is a per-unit property, not a per-port one
Which top-level unit's SMI interface to use should be a property of
the top-level unit, not of the individual ports.  This patch moves the
->shared_smi pointer from the per-port platform data to the global
platform data.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
2008-09-05 06:33:58 +02:00
Lennert Buytenhek
f7981c1c67 mv643xx_eth: require contiguous receive and transmit queue numbering
Simplify receive and transmit queue handling by requiring the set
of queue numbers to be contiguous starting from zero.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
2008-09-05 06:33:58 +02:00
Mauro Carvalho Chehab
db0a2901a3 Merge branch 'fixes_stg' of ../git_old into fixes 2008-09-04 16:24:02 -03:00
Ingo Molnar
8040d77688 Merge branch 'core/resources' into x86/core 2008-09-04 21:04:04 +02:00
Yinghai Lu
268364a0f4 IO resources: add reserve_region_with_split()
add reserve_region_with_split() to not lose e820 reserved entries if
they overlap with existing IO regions:

with test case by extend 0xe0000000 - 0xeffffff to 0xdd800000 -
we get:
	e0000000-efffffff : PCI MMCONFIG 0
		 e0000000-efffffff : reserved

and in /proc/iomem we get:
	found conflict for reserved [dd800000, efffffff], try to reserve with split
	    __reserve_region_with_split: (PCI Bus #80) [dd000000, ddffffff], res: (reserved) [dd800000, efffffff]
	    __reserve_region_with_split: (PCI Bus #00) [de000000, dfffffff], res: (reserved) [de000000, efffffff]
	initcall pci_subsys_init+0x0/0x121 returned 0 after 381 msecs
in dmesg

various fixes and improvements suggested by Linus.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-04 21:02:44 +02:00
H. Peter Anvin
0ccd8c39bc Merge branch 'linus' into x86/core 2008-09-04 08:09:09 -07:00
H. Peter Anvin
7203781c98 Merge branch 'x86/cpu' into x86/core
Conflicts:

	arch/x86/kernel/cpu/feature_names.c
	include/asm-x86/cpufeature.h
2008-09-04 08:08:42 -07:00
David Woodhouse
aa7a7fb399 Define and use PCI_DEVICE_ID_MARVELL_88ALP01_CCIC for CAFÉ camera driver
Also, stop looking at the NAND controller (0x4100) and checking the
device class. For a while during development, all three functions on the
chip had the same ID. We made them fix that fairly promptly, and we can
forget about it now.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
2008-09-04 09:46:00 +01:00
David Woodhouse
514fca4373 [MTD] [NAND] Define and use PCI_DEVICE_ID_MARVELL_88ALP01_NAND for CAFÉ
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2008-09-04 09:45:38 +01:00
David Woodhouse
8c5eb88058 Use PCI_DEVICE_ID_88ALP01 for CAFÉ chip, rather than PCI_DEVICE_ID_CAFE.
Probably better to use the official designation.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Pierre Ossman <drzeus@drzeus.cx>
2008-09-04 09:45:34 +01:00
Tomasz Grobelny
d6da3511d6 dccp: Policy-based packet dequeueing infrastructure
This patch adds a generic infrastructure for policy-based dequeueing of 
TX packets and provides two policies:
 * a simple FIFO policy (which is the default) and
 * a priority based policy (set via socket options).
Both policies honour the tx_qlen sysctl for the maximum size of the write
queue (can be overridden via socket options). 

The priority policy uses skb->priority internally to assign an u32 priority
identifier, using the same ranking as SO_PRIORITY. The skb->priority field
is set to 0 when the packet leaves DCCP. The priority is supplied as ancillary
data using cmsg(3), the patch also provides the requisite parsing routines.

Signed-off-by: Tomasz Grobelny <tomasz@grobelny.oswiecenia.net>
Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-04 07:45:39 +02:00
Gerrit Renker
e7937772d7 dccp: Extend CCID packet dequeueing interface
This extends the packet dequeuing interface of dccp_write_xmit() to allow
 1. CCIDs to take care of timing when the next packet may be sent;
 2. delayed sending (as before, with an inter-packet gap up to 65.535 seconds).

The main purpose is to take CCID2 out of its polling mode (when it is network-
limited, it tries every millisecond to send, without interruption).
The interface can also be used to support other CCIDs.

The mode of operation for (2) is as follows:
 * new packet is enqueued via dccp_sendmsg() => dccp_write_xmit(),
 * ccid_hc_tx_send_packet() detects that it may not send (e.g. window full), 
 * it signals this condition via `CCID_PACKET_WILL_DEQUEUE_LATER',
 * dccp_write_xmit() returns without further action;
 * after some time the wait-condition for CCID becomes true,
 * that CCID schedules the tasklet,
 * tasklet function calls ccid_hc_tx_send_packet() via dccp_write_xmit(),
 * since the wait-condition is now true, ccid_hc_tx_packet() returns "send now",
 * packet is sent, and possibly more (since dccp_write_xmit() loops).

Code reuse: the taskled function calls dccp_write_xmit(), the timer function
            reduces to a wrapper around the same code.

If the tasklet finds that the socket is locked, it re-schedules the tasklet
function (not the tasklet) after one jiffy.

Changed DCCP_BUG to dccp_pr_debug when transmit_skb returns an error (e.g. when a
local qdisc is used, NET_XMIT_DROP=1 can be returned for many packets).

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-04 07:45:38 +02:00
Gerrit Renker
c2f42077bd dccp ccid-2: Schedule Sync as out-of-band mechanism
The problem with Ack Vectors is that 

  i) their length is variable and can in principle grow quite large,
 ii) it is hard to predict exactly how large they will be.

Due to the second point it seems not a good idea to reduce the MPS; in
particular when on average there is enough room for the Ack Vector and an
increase in length is momentarily due to some burst loss, after which the
Ack Vector returns to its normal/average length.

The solution taken by this patch is to subtract a minimum-expected Ack Vector
length from the MPS (previous patch), and to defer any larger Ack Vectors onto
a separate Sync - but only if indeed there is no space left on the skb.

This patch provides the infrastructure to schedule Sync-packets for transporting
(urgent) out-of-band data. Its signalling is quicker than scheduling an Ack, since
it does not need to wait for new application data.

It can thus serve other parts of the DCCP code as well.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
2008-09-04 07:45:37 +02:00