Commit Graph

98647 Commits

Author SHA1 Message Date
Tony Lindgren
0499bdeb1d ARM: OMAP: DMA: Remove __REG access
Remove __REG access in DMA code, use dma_read/write instead:

- dynamically set the omap_dma_base based on the omap type
- omap_read/write becomes dma_read/write
- dma channel registers are read with dma_ch_read/write

Cc: David Brownell <david-b@pacbell.net>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Tony Lindgren <tony@atomide.com>
2008-07-03 12:24:36 +03:00
Tony Lindgren
4d96372e6d ARM: OMAP: DMA: Make channels dynamic for multi-boot
Make DMA channels dynamic for multi-boot

Signed-off-by: Tony Lindgren <tony@atomide.com>
2008-07-03 12:24:31 +03:00
Paul Walmsley
4a79acdc78 ARM: OMAP: Add OMAP3430 base defines
Add symbolic constants for OMAP3430 base addresses; include that file
in hardware.h.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2008-07-03 12:24:31 +03:00
Richard Woodruff
3fddd09e59 ARM: OMAP: DMTimer: Optimize by adding load and start
This patch optimizes the timer load and start sequence.  By combining the
load and start a needless posted wait can be removed from the system timer
execution path.

* Before patch register writes are taking up .078% @ 500MHz during idle.

 Address                 |total  |min  |max      |avr     |count|ratio%
 old\process\default_idle|7.369s |0.0us|999.902ms|14.477ms|509. |62.661%
 ld\Global\cpu_v7_do_idle|4.265s |0.0us|375.786ms|24.374ms|175. |36.270%
                (UNKNOWN)|17.503ms|0.us|531.080us|5.119us|3419. |0.148%
 r\omap_dm_timer_set_load|8.135ms|0.0us|79.887us|15.065us|540.  |0.069% <--
 \vmlinux-old\Global\_end|2.023ms|0.0us|4.000us|0.560us|3613.   |0.017%
 -old\Global\__raw_readsw|1.962ms|0.0us|108.610us|9.167us|214.  |0.016%
 old\smc91x\smc_interrupt|1.353ms|0.0us|10.212us|2.348us|576.   |0.011%
 s/namei\__link_path_walk|1.161ms|0.0us|4.310us|0.762us|  1524. |0.009%
 \omap_dm_timer_write_reg|1.085ms|0.0us|126.150us|2.153us|504.  |0.009% <--

* After patch timer functions do not show up in top listings for long captures.

Signed-off-by: Richard Woodruff <r-woodruff2@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2008-07-03 12:24:30 +03:00
Richard Woodruff
0f0d080709 ARM: OMAP: DMTimer: Use posted mode
This patch adds the use of write posting for the timer.  Previously, every
write could lock the requestor for almost 3x32KHz cycles.  This patch only
synchronizes before writes and reads instead of after them and it does
it on per register basis.  Doing it this way there is some chance to hide
some of the sync latency.  It also removes some needless reads when
non-posted mode is there.  With out this fix the read/writes take almost
2% CPU load @500MHz just waiting on tick timer registers.

Also define new 34xx only registers.

Signed-off-by: Richard Woodruff <r-woodruff2@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2008-07-03 12:24:30 +03:00
Thara Gopinath
4621d588e0 ARM: OMAP: Correcting the gpmc prefetch control register address
Correcting the GPMC_PREFETCH_CONTROL register address

Signed-off-by: Thara Gopinath <thara@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2008-07-03 12:24:30 +03:00
Jarkko Nikula
3f662c6eaa ARM: OMAP: DMA: Don't mark channel active in omap_enable_channel_irq
Channel should be marked active only when DMA is really started. Otherwise
just omap_request_dma, omap_dma_link_lch and omap_dma_unlink_lch will cause
incorrect dump_stack().

Signed-off-by: Jarkko Nikula <jarkko.nikula@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2008-07-03 12:24:29 +03:00
Linus Torvalds
c461a97311 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
  PCI: acpiphp: cleanup notify handler on all root bridges
  PCI: Limit VPD read/write lengths for Broadcom 5706, 5708, 5709 rev.
  PCI: Restrict VPD read permission to root
2008-07-02 19:29:16 -07:00
Linus Torvalds
9ad4107ba1 Merge branch 'i2c-fix' of git://aeryn.fluff.org.uk/bjdooks/linux
* 'i2c-fix' of git://aeryn.fluff.org.uk/bjdooks/linux:
  I2C: S3C2410: Add MODULE_ALIAS() for s3c2440 device.
  I2C: S3C2410: Fixup error codes returned rom a transfer.
  I2C: S3C2410: Check ACK on byte transmission
2008-07-02 19:26:38 -07:00
Linus Torvalds
0e77a07ff9 Merge branch 'for-2.6.26' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.26' of git://git.kernel.dk/linux-2.6-block:
  Properly notify block layer of sync writes
  block: Fix the starving writes bug in the anticipatory IO scheduler
2008-07-02 19:25:36 -07:00
Linus Torvalds
23c0e4a225 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
  [IA64] export account_system_vtime
  [IA64] Bugfix for system with 32 cpus
2008-07-02 19:24:48 -07:00
Linus Torvalds
3a57a78875 Merge git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb
* git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb:
  V4L/DVB (8178): uvc: Fix compilation breakage for the other drivers, if uvc is selected
  V4L/DVB (8145a): USB Video Class driver
2008-07-02 19:23:52 -07:00
Linus Torvalds
a16b4bcd31 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
  ide: fix /proc/ide/ide?/mate reporting
  Revert "BAST: Remove old IDE driver"
2008-07-02 19:22:54 -07:00
Linus Torvalds
15895b932b Merge master.kernel.org:/home/rmk/linux-2.6-arm
* master.kernel.org:/home/rmk/linux-2.6-arm:
  [ARM] 5131/1: Annotate platform_secondary_init with trace_hardirqs_off
  [ARM] 5117/1: pxafb: fix __devinit/exit annotations
  [ARM] Export dma_sync_sg_for_device()
  [ARM] 5109/1: Mark rtc sa1100 driver as wakeup source before registering it
  [ARM] 5116/1: pxafb: cleanup and fix order of failure handling
  [ARM] 5115/1: pxafb: fix ifdef for command line option handling
  ARM: OMAP: Correcting the gpmc prefetch control register address
  ARM: OMAP: DMA: Don't mark channel active in omap_enable_channel_irq
2008-07-02 19:22:25 -07:00
Alan Cox
3e2a078ca6 tty: Fix inverted logic in send_break
Not sure how this came to get inverted but it appears to have been my
mess up.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-02 19:21:48 -07:00
Linus Torvalds
b2a4a7ce3a 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 divide error when trying to configure rt_period to zero
2008-07-02 19:12:53 -07:00
Linus Torvalds
f7572da502 Merge branch 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6
* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6:
  i2c: Fix bad hint about irqs in i2c.h
  i2c: Documentation: fix device matching description
2008-07-02 19:00:29 -07:00
Linus Torvalds
c000131c71 Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: fix hotplug vs rcu race
2008-07-02 18:59:45 -07:00
Linus Torvalds
041924ec2f Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: fix NODES_SHIFT Kconfig range
2008-07-02 18:58:56 -07:00
Linus Torvalds
f36b7a2c17 Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
  [SCSI] esp: tidy up target reference counting
  [SCSI] esp: Fix OOPS in esp_reset_cleanup().
  [SCSI] ses: Fix timeout
2008-07-02 18:57:33 -07:00
Linus Torvalds
cefcade9e7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm
* git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm:
  dm crypt: use cond_resched
2008-07-02 18:55:17 -07:00
Linus Torvalds
c6b96d195a Merge branch 'for-2.6.26' of git://neil.brown.name/md
* 'for-2.6.26' of git://neil.brown.name/md:
  Fix error paths if md_probe fails.
  Don't acknowlege that stripe-expand is complete until it really is.
  Ensure interrupted recovery completed properly (v1 metadata plus bitmap)
2008-07-02 18:47:10 -07:00
Linus Torvalds
79ff1ad2ee Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
  powerpc/mpc5200: Fix lite5200b suspend/resume
  powerpc/legacy_serial: Bail if reg-offset/shift properties are present
  powerpc/bootwrapper: update for initrd with simpleImage
2008-07-02 18:45:29 -07:00
Linus Torvalds
821b03ffac Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (55 commits)
  net: fib_rules: fix error code for unsupported families
  netdevice: Fix wrong string handle in kernel command line parsing
  net: Tyop of sk_filter() comment
  netlink: Unneeded local variable
  net-sched: fix filter destruction in atm/hfsc qdisc destruction
  net-sched: change tcf_destroy_chain() to clear start of filter list
  ipv4: fix sysctl documentation of time related values
  mac80211: don't accept WEP keys other than WEP40 and WEP104
  hostap: fix sparse warnings
  hostap: don't report useless WDS frames by default
  textsearch: fix Boyer-Moore text search bug
  netfilter: nf_conntrack_tcp: fixing to check the lower bound of valid ACK
  ipv6 route: Convert rt6_device_match() to use RT6_LOOKUP_F_xxx flags.
  netlabel: Fix a problem when dumping the default IPv6 static labels
  net/inet_lro: remove setting skb->ip_summed when not LRO-able
  inet fragments: fix race between inet_frag_find and inet_frag_secret_rebuild
  CONNECTOR: add a proc entry to list connectors
  netlink: Fix some doc comments in net/netlink/attr.c
  tcp: /proc/net/tcp rto,ato values not scaled properly (v2)
  include/linux/netdevice.h: don't export MAX_HEADER to userspace
  ...
2008-07-02 18:43:16 -07:00
Jesse Barnes
3d25802e3b DRM/i915: only use tiled blits on 965+
When scheduled swaps occur, we need to blit between front & back
buffers.  If the buffers are tiled, we need to set the appropriate
XY_SRC_COPY tile bit, but only on 965 chips, since it will cause
corruption on pre-965 (e.g. 945).

Bug reported by and fix tested by Tomas Janousek <tomi@nomi.cz>.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Dave Airlie <airlied@linux.ie>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-02 18:42:23 -07:00
Geert Uytterhoeven
83680cdbce drivers/input/ff-core.c needs <linux/sched.h>
Commit 656acd2bbc ("Input: fix locking in
force-feedback core") causes the following regression on m68k:

| linux/drivers/input/ff-core.c: In function 'input_ff_upload':
| linux/drivers/input/ff-core.c:172: error: dereferencing pointer to incomplete type
| linux/drivers/input/ff-core.c: In function 'erase_effect':
| linux/drivers/input/ff-core.c:197: error: dereferencing pointer to incomplete type
| linux/drivers/input/ff-core.c:204: error: dereferencing pointer to incomplete type
| make[4]: *** [drivers/input/ff-core.o] Error 1

As the incomplete type is `struct task_struct', including <linux/sched.h> fixes
it.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-02 18:40:08 -07:00
Paul Mackerras
781c74b1e6 Merge branch 'for-2.6.26' of git://git.secretlab.ca/git/linux-2.6-mpc52xx into merge 2008-07-03 10:05:59 +10:00
Alex Chiang
a13307cef8 PCI: acpiphp: cleanup notify handler on all root bridges
During the development of the physical PCI slot patch series, Gary Hade
kept on reporting strange oopses due to interactions between pci_slot
and acpiphp.

	http://lkml.org/lkml/2007/11/28/319

find_root_bridges() unconditionally installs
handle_hotplug_event_bridge() as an ACPI_SYSTEM_NOTIFY handler for all
root bridges.

However, during module cleanup, remove_bridge() will only remove the
notify handler iff the root bridge had a hot-pluggable slot directly
underneath. That is:

	root bridge -> hotplug slot

But, if the topology looks like either of the following:

	root bridge -> non-hotplug slot
	root bridge -> p2p bridge -> hotplug slot

Then we currently do not remove the notify handler from that root
bridge.

This can cause a kernel oops if we modprobe acpiphp later and it gets
loaded somewhere else in memory. If the root bridge then receives a
hotplug event, it will then attempt to call a stale, non-existent notify
handler and we blow up.

Much thanks goes to Gary Hade for his persistent debugging efforts.

Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-02 11:27:30 -07:00
Benjamin Li
99cb233d60 PCI: Limit VPD read/write lengths for Broadcom 5706, 5708, 5709 rev.
For Broadcom 5706, 5708, 5709 rev. A nics, any read beyond the
VPD end tag will hang the device.  This problem was initially
observed when a vpd entry was created in sysfs
('/sys/bus/pci/devices/<id>/vpd').   A read to this sysfs entry
will dump 32k of data.  Reading a full 32k will cause an access
beyond the VPD end tag causing the device to hang.  Once the device
is hung, the bnx2 driver will not be able to reset the device.
We believe that it is legal to read beyond the end tag and
therefore the solution is to limit the read/write length.

A majority of this patch is from Matthew Wilcox who gave code for
reworking the PCI vpd size information.  A PCI quirk added for the
Broadcom NIC's to limit the read/write's.

Signed-off-by: Benjamin Li <benli@broadcom.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-02 11:25:54 -07:00
Mauro Carvalho Chehab
06f3ed23b1 V4L/DVB (8178): uvc: Fix compilation breakage for the other drivers, if uvc is selected
UVC makefile defines obj as:
	obj-$(CONFIG_USB_VIDEO_CLASS) := uvcvideo.o
Instead of:
	obj-$(CONFIG_USB_VIDEO_CLASS) += uvcvideo.o

Due to that, if uvc is selected, all obj-y or obj-m that were added to
compilation were forget. This breaks a proper kernel build.

Acked-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2008-07-02 08:58:15 -03:00
Milan Broz
c7f1b20441 dm crypt: use cond_resched
Add cond_resched() to prevent monopolising CPU when processing large bios.

dm-crypt processes encryption of bios in sector units.  If the bio request
is big it can spend a long time in the encryption call.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Tested-by: Yan Li <elliot.li.tech@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2008-07-02 09:34:28 +01:00
Patrick McHardy
2fe195cfe3 net: fib_rules: fix error code for unsupported families
The errno code returned must be negative.

Fixes "RTNETLINK answers: Unknown error 18446744073709551519".

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-01 19:59:37 -07:00
Wang Chen
93b3cff991 netdevice: Fix wrong string handle in kernel command line parsing
v1->v2: Use strlcpy() to ensure s[i].name be null-termination.

1. In netdev_boot_setup_add(), a long name will leak.
   ex. : dev=21,0x1234,0x1234,0x2345,eth123456789verylongname.........
2. In netdev_boot_setup_check(), mismatch will happen if s[i].name
   is a substring of dev->name.
   ex. : dev=...eth1 dev=...eth11

[ With feedback from Ben Hutchings. ]

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-01 19:57:19 -07:00
Wang Chen
8fde8a0769 net: Tyop of sk_filter() comment
Parameter "needlock" no long exists.

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-01 19:55:40 -07:00
Wang Chen
8487460720 netlink: Unneeded local variable
We already have a variable, which has the same capability.

Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-01 19:55:09 -07:00
Patrick McHardy
a4aebb83cf net-sched: fix filter destruction in atm/hfsc qdisc destruction
Filters need to be destroyed before beginning to destroy classes
since the destination class needs to still be alive to unbind the
filter.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-01 19:53:09 -07:00
Patrick McHardy
ff31ab56c0 net-sched: change tcf_destroy_chain() to clear start of filter list
Pass double tcf_proto pointers to tcf_destroy_chain() to make it
clear the start of the filter list for more consistency.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-01 19:52:38 -07:00
Stephen Hemminger
77a538d5aa ipv4: fix sysctl documentation of time related values
These sysctl values are time related and all use the same routine
(proc_dointvec_jiffies) that internally converts from seconds to jiffies.
The code is fine, the documentation is just wrong.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-01 17:22:48 -07:00
Tim Yamin
18d76ac9a4 powerpc/mpc5200: Fix lite5200b suspend/resume
Suspend/resume ("echo mem > /sys/power/state") does not work with
vanilla kernels -- the system does not suspend correctly and just
hangs. This patch fixes this so suspend/resume works:

1) of_iomap does not map the whole 0xC000 of the MPC5200 immr so
saving registers does not work.
2) PCI registers need to be saved and restored.

Signed-off-by: Tim Yamin <plasm@roo.me.uk>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-07-01 16:08:24 -06:00
John Linn
1e6d1f2606 powerpc/legacy_serial: Bail if reg-offset/shift properties are present
The legacy serial driver does not work with an 8250 type UART that is
described in the device tree with the reg-offset and reg-shift
properties.  This change makes legacy_serial ignore these devices.

Signed-off-by: John Linn <john.linn@xilinx.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-07-01 15:12:37 -06:00
Wolfram Sang
8e29da9ee8 i2c: Fix bad hint about irqs in i2c.h
i2c.h mentions -1 as a not-issued irq. This false hint was taken by
of_i2c and caused crashes. Don't give any advice as 'no irq' is not
consistent across all architectures yet and it is not needed internally
by the i2c-core.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-01 22:38:18 +02:00
Ben Dooks
2260e63a2f i2c: Documentation: fix device matching description
The matching process described for new style clients in
Documentation/i2c/writing-clients is classed as out-of-date
as it requires the presence of an .id_table entry in the
driver's i2c_driver entry.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-01 22:38:18 +02:00
John Linn
5d1a04110b powerpc/bootwrapper: update for initrd with simpleImage
This change to the makefile corrects the build of a simpleImage with initrd.

Signed-off-by: John Linn <john.linn@xilinx>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2008-07-01 14:17:18 -06:00
Ben Hutchings
a94c248113 PCI: Restrict VPD read permission to root
Some PCI devices will lock up if we attempt to read from VPD addresses
beyond some device-dependent limit.  Until we can identify these
devices and adjust the file size accordingly, only let root read VPD
through sysfs to prevent a DoS by normal users.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2008-07-01 09:51:53 -07:00
Ben Dooks
d150a4bbd0 I2C: S3C2410: Add MODULE_ALIAS() for s3c2440 device.
Add a MODULE_ALIAS() statement for the i2c-s3c2410 controller
to ensure that it can be autoloaded on the S3C2440 systems that
we support.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2008-07-01 14:30:38 +01:00
Ben Dooks
63f5c2891e I2C: S3C2410: Fixup error codes returned rom a transfer.
The driver should be returning -ENXIO for transfers that do not
pass the initial address byte stage.

Note, also small tidyups to the driver comments in the area.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2008-07-01 14:30:37 +01:00
Ben Dooks
2709781be6 I2C: S3C2410: Check ACK on byte transmission
We should check for the reception of an ACK after transmitting each
data byte. The address send has been correctly checking this, but the
data write byte state should have also been checking for these failures.

As part of the same fix, we remove the ACK checking from the receive
path where it should not have been checking for an ACK which our hardware
was sending.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2008-07-01 14:30:37 +01:00
Gautham R Shenoy
8558f8f816 rcu: fix hotplug vs rcu race
Dhaval Giani reported this warning during cpu hotplug stress-tests:

| On running kernel compiles in parallel with cpu hotplug:
|
| WARNING: at arch/x86/kernel/smp.c:118
| native_smp_send_reschedule+0x21/0x36()
| Modules linked in:
| Pid: 27483, comm: cc1 Not tainted 2.6.26-rc7 #1
| [...]
|  [<c0110355>] native_smp_send_reschedule+0x21/0x36
|  [<c014fe8f>] force_quiescent_state+0x47/0x57
|  [<c014fef0>] call_rcu+0x51/0x6d
|  [<c01713b3>] __fput+0x130/0x158
|  [<c0171231>] fput+0x17/0x19
|  [<c016fd99>] filp_close+0x4d/0x57
|  [<c016fdff>] sys_close+0x5c/0x97

IMHO the warning is a spurious one.

cpu_online_map is updated by the _cpu_down() using stop_machine_run().
Since force_quiescent_state is invoked from irqs disabled section,
stop_machine_run() won't be executing while a cpu is executing
force_quiescent_state(). Hence the cpu_online_map is stable while we're
in the irq disabled section.

However, a cpu might have been offlined _just_ before we disabled irqs
while entering force_quiescent_state(). And rcu subsystem might not yet
have handled the CPU_DEAD notification, leading to the offlined cpu's
bit being set in the rcp->cpumask.

Hence cpumask = (rcp->cpumask & cpu_online_map) to prevent sending
smp_reschedule() to an offlined CPU.

Here's the timeline:

CPU_A						 CPU_B
--------------------------------------------------------------
cpu_down():					.
.					   	.
.						.
stop_machine(): /* disables preemption,		.
		 * and irqs */			.
.						.
.						.
take_cpu_down();				.
.						.
.						.
.						.
cpu_disable(); /*this removes cpu 		.
		*from cpu_online_map 		.
		*/				.
.						.
.						.
restart_machine(); /* enables irqs */		.
------WINDOW DURING WHICH rcp->cpumask is stale ---------------
.						call_rcu();
.						/* disables irqs here */
.						.force_quiescent_state();
.CPU_DEAD:					.for_each_cpu(rcp->cpumask)
.						.   smp_send_reschedule();
.						.
.						.   WARN_ON() for offlined CPU!
.
.
.
rcu_cpu_notify:
.
-------- WINDOW ENDS ------------------------------------------
rcu_offline_cpu() /* Which calls cpu_quiet()
		   * which removes
		   * cpu from rcp->cpumask.
		   */

If a new batch was started just before calling stop_machine_run(), the
"tobe-offlined" cpu is still present in rcp-cpumask.

During a cpu-offline, from take_cpu_down(), we queue an rt-prio idle
task as the next task to be picked by the scheduler. We also call
cpu_disable() which will disable any further interrupts and remove the
cpu's bit from the cpu_online_map.

Once the stop_machine_run() successfully calls take_cpu_down(), it calls
schedule(). That's the last time a schedule is called on the offlined
cpu, and hence the last time when rdp->passed_quiesc will be set to 1
through rcu_qsctr_inc().

But the cpu_quiet() will be on this cpu will be called only when the
next RCU_SOFTIRQ occurs on this CPU. So at this time, the offlined CPU
is still set in rcp->cpumask.

Now coming back to the idle_task which truely offlines the CPU, it does
check for a pending RCU and raises the softirq, since it will find
rdp->passed_quiesc to be 0 in this case. However, since the cpu is
offline I am not sure if the softirq will trigger on the CPU.

Even if it doesn't the rcu_offline_cpu() will find that rcp->completed
is not the same as rcp->cur, which means that our cpu could be holding
up the grace period progression. Hence we call cpu_quiet() and move
ahead.

But because of the window explained in the timeline, we could still have
a call_rcu() before the RCU subsystem executes it's CPU_DEAD
notification, and we send smp_send_reschedule() to offlined cpu while
trying to force the quiescent states. The appended patch adds comments
and prevents checking for offlined cpu everytime.

cpu_online_map is updated by the _cpu_down() using stop_machine_run().
Since force_quiescent_state is invoked from irqs disabled section,
stop_machine_run() won't be executing while a cpu is executing
force_quiescent_state(). Hence the cpu_online_map is stable while we're
in the irq disabled section.

Reported-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rusty Russel <rusty@rustcorp.com.au>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-01 09:27:17 +02:00
Jens Axboe
18ce3751cc Properly notify block layer of sync writes
fsync_buffers_list() and sync_dirty_buffer() both issue async writes and
then immediately wait on them. Conceptually, that makes them sync writes
and we should treat them as such so that the IO schedulers can handle
them appropriately.

This patch fixes a write starvation issue that Lin Ming reported, where
xx is stuck for more than 2 minutes because of a large number of
synchronous IO in the system:

INFO: task kjournald:20558 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
kjournald     D ffff810010820978  6712 20558      2
ffff81022ddb1d10 0000000000000046 ffff81022e7baa10 ffffffff803ba6f2
ffff81022ecd0000 ffff8101e6dc9160 ffff81022ecd0348 000000008048b6cb
0000000000000086 ffff81022c4e8d30 0000000000000000 ffffffff80247537
Call Trace:
[<ffffffff803ba6f2>] kobject_get+0x12/0x17
[<ffffffff80247537>] getnstimeofday+0x2f/0x83
[<ffffffff8029c1ac>] sync_buffer+0x0/0x3f
[<ffffffff8066d195>] io_schedule+0x5d/0x9f
[<ffffffff8029c1e7>] sync_buffer+0x3b/0x3f
[<ffffffff8066d3f0>] __wait_on_bit+0x40/0x6f
[<ffffffff8029c1ac>] sync_buffer+0x0/0x3f
[<ffffffff8066d48b>] out_of_line_wait_on_bit+0x6c/0x78
[<ffffffff80243909>] wake_bit_function+0x0/0x23
[<ffffffff8029e3ad>] sync_dirty_buffer+0x98/0xcb
[<ffffffff8030056b>] journal_commit_transaction+0x97d/0xcb6
[<ffffffff8023a676>] lock_timer_base+0x26/0x4b
[<ffffffff8030300a>] kjournald+0xc1/0x1fb
[<ffffffff802438db>] autoremove_wake_function+0x0/0x2e
[<ffffffff80302f49>] kjournald+0x0/0x1fb
[<ffffffff802437bb>] kthread+0x47/0x74
[<ffffffff8022de51>] schedule_tail+0x28/0x5d
[<ffffffff8020cac8>] child_rip+0xa/0x12
[<ffffffff80243774>] kthread+0x0/0x74
[<ffffffff8020cabe>] child_rip+0x0/0x12

Lin Ming confirms that this patch fixes the issue. I've run tests with
it for the past week and no ill effects have been observed, so I'm
proposing it for inclusion into 2.6.26.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-01 09:07:34 +02:00
Divyesh Shah
d585d0b9d7 block: Fix the starving writes bug in the anticipatory IO scheduler
AS scheduler alternates between issuing read and write batches. It does
the batch switch only after all requests from the previous batch are
completed.

When switching to a write batch, if there is an on-going read request,
it waits for its completion and indicates its intention of switching by
setting ad->changed_batch and the new direction but does not update the
batch_expire_time for the new write batch which it does in the case of
no previous pending requests.
On completion of the read request, it sees that we were waiting for the
switch and schedules work for kblockd right away and resets the
ad->changed_data flag.
Now when kblockd enters dispatch_request where it is expected to pick
up a write request, it in turn ends the write batch because the
batch_expire_timer was not updated and shows the expire timestamp for
the previous batch.

This results in the write starvation for all the cases where there is
the intention for switching to a write batch, but there is a previous
in-flight read request and the batch gets reverted to a read_batch
right away.

This also holds true in the reverse case (switching from a write batch
to a read batch with an in-flight write request).

I've checked that this bug exists on 2.6.11, 2.6.18, 2.6.24 and
linux-2.6-block git HEAD. I've tested the fix on x86 platforms with
SCSI drives where the driver asks for the next request while a current
request is in-flight.

This patch is based off linux-2.6-block git HEAD.

Bug reproduction:
A simple scenario which reproduces this bug is:
- dd if=/dev/hda3 of=/dev/null &
- lilo
   The lilo takes forever to complete.

This can also be reproduced fairly easily with the earlier dd and
another test
program doing msync().

The example test program below should print out a message after every
iteration
but it simply hangs forever. With this bugfix it makes forward progress.

====
Example test program using msync() (thanks to suleiman AT google DOT
com)

inline uint64_t
rdtsc(void)
{
         int64_t tsc;

         __asm __volatile("rdtsc" : "=A" (tsc));
         return (tsc);
}

int
main(int argc, char **argv)
{
         struct stat st;
         uint64_t e, s, t;
         char *p, q;
         long i;
         int fd;

         if (argc < 2) {
                 printf("Usage: %s <file>\n", argv[0]);
                 return (1);
         }

         if ((fd = open(argv[1], O_RDWR | O_NOATIME)) < 0)
                 err(1, "open");

         if (fstat(fd, &st) < 0)
                 err(1, "fstat");

         p = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE,
MAP_SHARED, fd, 0);

         t = 0;
         for (i = 0; i < 1000; i++) {
                 *p = 0;
                 msync(p, 4096, MS_SYNC);
                 s = rdtsc();
                *p = 0;
                 __asm __volatile(""::: "memory");
                 e = rdtsc();
                 if (argc > 2)
                         printf("%d: %lld cycles %jd %jd\n",
                                i, e - s, (intmax_t)s, (intmax_t)e);
                 t += e - s;
         }
         printf("average time: %lld cycles\n", t / 1000);
         return (0);
}

Cc: <stable@kernel.org>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-07-01 09:06:42 +02:00