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101070 commits

Author SHA1 Message Date
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
Haavard Skinnemoen
02a00cf672 avr32: Power Management support ("standby" and "mem" modes)
Implement Standby support. In this mode, we'll suspend all drivers,
put the SDRAM in self-refresh mode and switch off the HSB bus
("frozen" mode.)

Implement Suspend-to-mem support. In this mode, we suspend all
drivers, put the SDRAM into self-refresh mode and switch off all
internal clocks except the 32 kHz oscillator ("stop" mode.)

The lowest-level suspend code runs from a small portion of SRAM
allocated at startup time. This gets rid of a small potential race
with the SDRAM where we might try to enter self-refresh mode in the
middle of an icache burst. We also relocate all interrupt and
exception handlers to SRAM during the small window when we enter and
exit the low-power modes.

We don't need to do any special tricks to start and stop the PLL. The
main clock is automatically gated by hardware until the PLL is stable.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2008-07-02 11:05:01 +02:00
Haavard Skinnemoen
aa8e87ca61 avr32: Add system device for the internal interrupt controller (intc)
This makes the intc show up in sysfs (probably not very useful), and
allows us to easily add suspend/resume support later.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2008-07-02 11:05:01 +02:00
Haavard Skinnemoen
b83d6ee175 avr32: Add simple SRAM allocator
Add SRAM allocator for avr32, which is just a thin wrapper around
genalloc.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2008-07-02 11:05:01 +02:00
Haavard Skinnemoen
7951f188a0 avr32: Enable SDRAMC clock at startup
The SDRAM controller needs a clock in order to respond to our
commands, and suspend doesn't work very well without the SDRAM in
self-refresh mode.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2008-07-02 11:05:01 +02:00
Haavard Skinnemoen
f3a24e1e27 rtc-at32ap700x: Enable wakeup
Call device_init_wakeup() to signal that the RTC is capable of waking
the system. This is needed for rtcwake to work.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
2008-07-02 11:05:01 +02:00
Haavard Skinnemoen
c1f598fd71 macb: Basic suspend/resume support
This implements suspend and resume callbacks for the macb driver. We may
have to do some more to gracefully shut the MAC down, but this at least
prevents the macb from waking the system when hooked up to a busy
network.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Patrice Vilchez <patrice.vilchez@rfo.atmel.com>
Cc: Nicolas FERRE <nicolas.ferre@rfo.atmel.com>
2008-07-02 11:05:00 +02:00
Haavard Skinnemoen
e1c609efbc atmel_serial: Drain console TX shifter before suspending
Funny things may happen if we stop the USART clock before the shifter is
empty. Prevent this from happening by waiting until the shifter is
completely drained before allowing suspend to continue.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Cc: Andrew Victor <linux@maxim.org.za>
2008-07-02 11:05:00 +02:00
Haavard Skinnemoen
f826caa449 atmel_serial: Fix build on avr32 with CONFIG_PM enabled
AVR32 doesn't have at91_suspend_entering_slow_clock(). Just assume the
clock will keep running for now.

David has a better solution for this, but this works for now. Leaving
the USART clock running won't prevent the PM code from entering deep
power-down modes anyway.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Andrew Victor <linux@maxim.org.za>
2008-07-02 11:05:00 +02:00
Haavard Skinnemoen
38510754a5 avr32: Use a quicklist for PTE allocation as well
Using a quicklist to allocate PTEs might be slightly faster than using
the page allocator directly since we might avoid zeroing the page
after each allocation.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-07-02 11:01:29 +02:00
Haavard Skinnemoen
5a4d529277 avr32: Use a quicklist for PGD allocation
Use a quicklist to allocate process PGDs. This is expected to be
slightly faster since we need to copy entries from swapper_pg_dir,
which can stay around for pages on the PGD quick list.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-07-02 11:01:29 +02:00
Haavard Skinnemoen
a9a934f278 avr32: Cover the kernel page tables in the user PGDs
Expand the per-process PGDs so that they cover the kernel virtual
memory area as well. This simplifies the TLB miss handler fastpath
since it doesn't have to check for kernel addresses anymore.

If a TLB miss happens on a kernel address and a second-level page
table can't be found, we check swapper_pg_dir and copy the PGD entry
into the user PGD if it can be found there.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-07-02 11:01:29 +02:00
Haavard Skinnemoen
cfd23e93a0 avr32: Store virtual addresses in the PGD
Instead of storing physical addresses along with page flags in the
PGD, store virtual addresses and use NULL to indicate a not present
second-level page table. A non-page-aligned page table indicates a bad
PMD.

This simplifies the TLB miss handler since it no longer has to check
the Present bit and no longer has to convert the PGD entry from
physical to virtual address. Instead, it has to check for a NULL
entry, which is slightly cheaper than either.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-07-02 11:01:28 +02:00
Haavard Skinnemoen
ebe74597a5 avr32: Remove useless zeroing of swapper_pg_dir at startup
swapper_pg_dir is stored in .bss, so it must already be zeroed out
when we get there.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-07-02 11:01:28 +02:00
Haavard Skinnemoen
b13d618b44 avr32: Clean up and optimize the TLB operations
This and the following patches aim to optimize the code dealing with
page tables and TLB operations. Each patch reduces the time it takes
to gzip a 16 MB file slightly, but I expect things like fork() and
mmap() will improve somewhat more.

This patch deals with the low-level TLB operations:

  * Remove unused _TLBEHI_I define
  * Use gcc builtins instead of inline assembly
  * Remove a few unnecessary pipeline flushes and nops
  * Introduce NR_TLB_ENTRIES define and use it instead of hardcoding it
    to 32 a few places throughout the code.
  * Use sysreg bitops instead of hardcoded shifts and masks
  * Make a few needlessly global functions static

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2008-07-02 11:01:28 +02:00
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
Ingo Molnar
760378e149 fix "ftrace: store mcount address in rec->ip"
Alexander Beregalov reported this build failure:

$ make CROSS_COMPILE=sparc64-unknown-linux-gnu- image modules && sudo
make modules_install
  CHK     include/linux/version.h
  CHK     include/linux/utsrelease.h
  CALL    scripts/checksyscalls.sh
  CHK     include/linux/compile.h
dnsdomainname: Unknown host
  CC      arch/sparc64/kernel/sparc64_ksyms.o
arch/sparc64/kernel/sparc64_ksyms.c:116: error: '_mcount' undeclared
here (not in a function)
cc1: warnings being treated as errors
arch/sparc64/kernel/sparc64_ksyms.c:116: error: type defaults to 'int'
in declaration of '_mcount'

And bisected it back to:

| commit 395a59d0f8
| Author: Abhishek Sagar <sagar.abhishek@gmail.com>
| Date:   Sat Jun 21 23:47:27 2008 +0530
|
|     ftrace: store mcount address in rec->ip

the mcount prototype is only available under CONFIG_FTRACE,
extend it to CONFIG_MCOUNT as well.

Reported-and-bisected-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-01 17:46:14 +02:00
Vegard Nossum
f294a8ce21 x86: small unifications of address printing
'man 3 printf' tells me that %p should be printed as if by %#x, but
this is not true for the kernel, which does not use the '0x' prefix
for the %p conversion specifier.

A small cast to (void *) is also prettier than #ifdef/#else/#endif.

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-01 16:21:41 +02:00
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
Roland McGrath
45fdc3a762 x86 ptrace: fix PTRACE_GETFPXREGS error
ptrace has always returned only -EIO for all failures to access
registers.  The user_regset calls are allowed to return a more
meaningful variety of errors.  The REGSET_XFP calls use -ENODEV
for !cpu_has_fxsr hardware.  Make ptrace return the traditional
-EIO instead of the error code from the user_regset call.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-01 11:03:31 +02:00
H. Peter Anvin
2ee2394b68 x86: fix regression: boot failure on AMD Elan TS-5500
Jeremy Fitzhardinge wrote:
>
> Maybe it really does require the far jump immediately after setting PE
> in cr0...
>
> Hm, I don't remember this paragraph being in vol 3a, section 8.9.1
> before.  Is it a recent addition?
>
>    Random failures can occur if other instructions exist between steps
>    3 and 4 above.  Failures will be readily seen in some situations,
>    such as when instructions that reference memory are inserted between
>    steps 3 and 4 while in system management mode.
>

I don't remember that, either.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-01 10:53:29 +02:00
Pekka Paalanen
3e61e0c976 mmiotrace broken in linux-next (8-bit writes only)
The moment mmiotrace is enabled, I hit a NULL deref in:

IP: [<ffffffff80256e71>] __trace_special+0x17c/0x23a
Call Trace:
 [<ffffffff802573cc>] ftrace_special+0x6f/0x9a
 [<ffffffff8023e3e4>] down+0x19/0x4a
 [<ffffffff80228adc>] acquire_console_sem+0x42/0x58
 [<ffffffff8035d273>] con_flush_chars+0x28/0x43
 [<ffffffff80354a70>] write_chan+0x22e/0x334
 [<ffffffff802244e9>] ? default_wake_function+0x0/0xf
 [<ffffffff8035236d>] tty_write+0x195/0x228
 [<ffffffff80354842>] ? write_chan+0x0/0x334
 [<ffffffff8027c23a>] vfs_write+0xae/0x137
 [<ffffffff8027c6e3>] sys_write+0x47/0x70
 [<ffffffff8020b1db>] system_call_after_swapgs+0x7b/0x80

which means 'entry' in __trace_special() is NULL.

[ mingo@elte.hu: that ftrace_special() was a leftover. ]

Signed-off-by: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: proski@gnu.org
Cc: "Vegard Nossum" <vegard.nossum@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-01 10:14:06 +02:00
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
Thomas Gleixner
efac41894d x86: fix NODES_SHIFT Kconfig range
commit 4323838215
       x86: change size of node ids from u8 to s16

set the range for NODES_SHIFT to 1..15.

The possible range is 1..9

Fixes Bugzilla #10726

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-07-01 08:56:32 +02:00
Raistlin
619b048803 sched: fix divide error when trying to configure rt_period to zero
Here it is another little Oops we found while configuring invalid values
via cgroups:

echo 0 > /dev/cgroups/0/cpu.rt_period_us
or
echo 4294967296 > /dev/cgroups/0/cpu.rt_period_us

[  205.509825] divide error: 0000 [#1]
[  205.510151] Modules linked in:
[  205.510151]
[  205.510151] Pid: 2339, comm: bash Not tainted (2.6.26-rc8 #33)
[  205.510151] EIP: 0060:[<c030c6ef>] EFLAGS: 00000293 CPU: 0
[  205.510151] EIP is at div64_u64+0x5f/0x70
[  205.510151] EAX: 0000389f EBX: 00000000 ECX: 00000000 EDX: 00000000
[  205.510151] ESI: d9800000 EDI: 00000000 EBP: c6cede60 ESP: c6cede50
[  205.510151]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
[  205.510151] Process bash (pid: 2339, ti=c6cec000 task=c79be370 task.ti=c6cec000)
[  205.510151] Stack: d9800000 0000389f c05971a0 d9800000 c6cedeb4 c0214dbd 00000000 00000000
[  205.510151]        c6cede88 c0242bd8 c05377c0 c7a41b40 00000000 00000000 00000000 c05971a0
[  205.510151]        c780ed20 c7508494 c7a41b40 00000000 00000002 c6cedebc c05971a0 ffffffea
[  205.510151] Call Trace:
[  205.510151]  [<c0214dbd>] ? __rt_schedulable+0x1cd/0x240
[  205.510151]  [<c0242bd8>] ? cgroup_file_open+0x18/0xe0
[  205.510151]  [<c0214fe4>] ? tg_set_bandwidth+0xa4/0xf0
[  205.510151]  [<c0215066>] ? sched_group_set_rt_period+0x36/0x50
[  205.510151]  [<c021508e>] ? cpu_rt_period_write_uint+0xe/0x10
[  205.510151]  [<c0242dc5>] ? cgroup_file_write+0x125/0x160
[  205.510151]  [<c0232c15>] ? hrtimer_interrupt+0x155/0x190
[  205.510151]  [<c02f047f>] ? security_file_permission+0xf/0x20
[  205.510151]  [<c0277ad8>] ? rw_verify_area+0x48/0xc0
[  205.510151]  [<c0283744>] ? dupfd+0x104/0x130
[  205.510151]  [<c027838c>] ? vfs_write+0x9c/0x160
[  205.510151]  [<c0242ca0>] ? cgroup_file_write+0x0/0x160
[  205.510151]  [<c027850d>] ? sys_write+0x3d/0x70
[  205.510151]  [<c0203019>] ? sysenter_past_esp+0x6a/0x91
[  205.510151]  =======================
[  205.510151] Code: 0f 45 de 31 f6 0f ad d0 d3 ea f6 c1 20 0f 45 c2 0f 45 d6 89 45 f0 89 55 f4 8b 55 f4 31 c9 8b 45 f0 39 d3 89 c6 77 08 89 d0 31 d2 <f7> f3 89 c1 83 c4 08 89 f0 f7 f3 89 ca 5b 5e 5d c3 55 89 e5 56
[  205.510151] EIP: [<c030c6ef>] div64_u64+0x5f/0x70 SS:ESP 0068:c6cede50

The attached patch solves the issue for me.

I'm checking as soon as possible for the period not being zero since, if
it is, going ahead is useless. This way we also save a mutex_lock() and
a read_lock() wrt doing it inside tg_set_bandwidth() or
__rt_schedulable().

Signed-off-by: Dario Faggioli <raistlin@linux.it>
Signed-off-by: Michael Trimarchi <trimarchimichael@yahoo.it>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-01 08:23:24 +02:00
H. Peter Anvin
908ec7afac x86: remove arbitrary ELF section limit in i386 relocatable kernel
Impact: build failure in maximal configurations

The 32-bit x86 relocatable kernel requires an auxilliary host program
to process the relocations.  This program had a hard-coded arbitrary
limit of a 100 ELF sections.  Instead of a hard-coded limit, allocate
the structures dynamically.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
2008-06-30 20:22:58 -07:00
Doug Chapman
3a677d2164 [IA64] export account_system_vtime
The symbol account_system_vtime is used by the kvm module but
not exported.  This breaks building with CONFIG_VIRT_CPU_ACCOUNTING
and CONFIG_KVM=m.

Signed-off-by: Doug Chapman <doug.chapman@hp.com>
Acked-by: Hidetosho Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-06-30 15:06:48 -07:00
Tony Luck
dd4f0888f8 [IA64] Bugfix for system with 32 cpus
On a system where there are no hot pluggable cpus "additional_cpus"
is still set to -1 at the point where we call per_cpu_scan_finalize().
If we didn't find an SRAT table and so pick the default "32" for the
number of cpus, when we get to:
high_cpu = min(high_cpu + reserve_cpus, NR_CPUS);
we will end up initializing for just 31 cpus ... and so we will
die horribly when bringing up cpu#32.

Problem introduced by: 2c6e6db41f
"Minimize per_cpu reservations."

Acked-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
2008-06-30 15:03:14 -07:00
Laurent Pinchart
c0efd23292 V4L/DVB (8145a): USB Video Class driver
This driver supports video input devices compliant with the USB Video Class
specification. This means lots of currently manufactured webcams, and probably
most of the future ones.

Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2008-06-30 17:31:13 -03:00
David S. Miller
2a64cc4b79 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/linville/wireless-2.6 2008-06-30 13:18:53 -07:00
Saeed Bishara
5b2353859f [ARM] Kirkwood: use chip_delay
Signed-off-by: Saeed Bishara <saeed@marvell.com>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
2008-06-30 16:04:46 -04:00
Saeed Bishara
f4db56ffd4 [MTD] orion_nand: add chip_delay parameter
Some SoCs need a different chip_delay value.

Signed-off-by: Saeed Bishara <saeed@marvell.com>
Acked-by: Jörn Engel <joern@logfs.org>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
2008-06-30 16:04:45 -04:00
Imre Kaloz
395aed6de6 [ARM] Orion: enable all currently supported boards in defconfig
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
2008-06-30 16:04:45 -04:00