Commit Graph

37800 Commits

Author SHA1 Message Date
Matthew Garrett
31373d09da laptop-mode: Make flushes per-device
One of the features of laptop-mode is that it forces a writeout of dirty
pages if something else triggers a physical read or write from a device.
The current implementation flushes pages on all devices, rather than only
the one that triggered the flush. This patch alters the behaviour so that
only the recently accessed block device is flushed, preventing other
disks being spun up for no terribly good reason.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-06 14:25:14 +02:00
H Hartley Sweeten
9d32c30542 Input: matrix_keypad - allow platform to disable key autorepeat
In an embedded system the matrix_keypad driver might be used to
interface with an external control panel and not an actual keyboard.
On the control panel some of the keys could be used to turn on/off
various functions.  If key autorepeat is enabled this causes the
function to quickly toggle between the on and off states and makes
operation difficult.

Add an option in the platform-specific data to disable the key
autorepeat.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-04-05 23:02:00 -07:00
Nick Piggin
5fbfb18d7a Fix up possibly racy module refcounting
Module refcounting is implemented with a per-cpu counter for speed.
However there is a race when tallying the counter where a reference may
be taken by one CPU and released by another.  Reference count summation
may then see the decrement without having seen the previous increment,
leading to lower than expected count.  A module which never has its
actual reference drop below 1 may return a reference count of 0 due to
this race.

Module removal generally runs under stop_machine, which prevents this
race causing bugs due to removal of in-use modules.  However there are
other real bugs in module.c code and driver code (module_refcount is
exported) where the callers do not run under stop_machine.

Fix this by maintaining running per-cpu counters for the number of
module refcount increments and the number of refcount decrements.  The
increments are tallied after the decrements, so any decrement seen will
always have its corresponding increment counted.  The final refcount is
the difference of the total increments and decrements, preventing a
low-refcount from being returned.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-05 19:50:02 -07:00
Pauli Nieminen
c96af79e34 drm/ttm: Add sysfs interface to control pool allocator.
Sysfs interface allows user to configure pool allocator functionality and
change limits for the size of pool.

Signed-off-by: Pauli Nieminen <suokkos@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-04-06 11:36:18 +10:00
Pauli Nieminen
0745866165 drm/ttm: Add debugfs output entry to pool allocator.
ttm_page_alloc_debugfs can be registered to output the state
of pools.

Debugfs file will output number of pages freed from the pool,
number of pages in pool now and the lowes number of pages in
pool since previous shrink.

Signed-off-by: Pauli Nieminen <suokkos@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-04-06 11:35:45 +10:00
Pauli Nieminen
1403b1a38e drm/ttm: add pool wc/uc page allocator V3
On AGP system we might allocate/free routinely uncached or wc memory,
changing page from cached (wb) to uc or wc is very expensive and involves
a lot of flushing. To improve performance this allocator use a pool
of uc,wc pages.

Pools are protected with spinlocks to allow multiple threads to allocate pages
simultanously. Expensive operations are done outside of spinlock to maximize
concurrency.

Pools are linked lists of pages that were recently freed. mm shrink callback
allows kernel to claim back pages when they are required for something else.

Fixes:
* set_pages_array_wb handles highmem pages so we don't have to remove them
  from pool.
* Add count parameter to ttm_put_pages to avoid looping in free code.
* Change looping from _safe to normal in pool fill error path.
* Initialize sum variable and make the loop prettier in get_num_unused_pages.

* Moved pages_freed reseting inside the loop in ttm_page_pool_free.
* Add warning comment about spinlock context in ttm_page_pool_free.

Based on Jerome Glisse's and Dave Airlie's pool allocator.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Pauli Nieminen <suokkos@gmail.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-04-06 11:35:26 +10:00
Adam Jackson
7a37435008 drm/edid: Add secondary GTF curve support
Before CVT-R, some monitors would advertise support for an alternative
GTF formula with lower blanking intervals.  Correctly identify such
monitors, and use the alternative formula when generating modes for
them.

Note that we only do this for "standard" timing descriptors (tuples of
hsize in characters / aspect ratio / vertical refresh).  Range-based
mode lists still only refer to the primary GTF curve.  It would be
possible to do better for the latter case, but monitors are required to
support the primary curve over the entire advertised range, so all it
would win you is a lower pixel clock and therefore possibly better image
quality on analog links.

Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-04-06 10:40:25 +10:00
Adam Jackson
7466f4cc50 drm/edid: Remove arbitrary EDID extension limit
Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-04-06 10:40:20 +10:00
Adam Jackson
61e57a8d72 drm/edid: Fix secondary block fetch.
This makes fetching the second EDID block on HDMI monitors actually
work.  DDC can't transfer more than 128 bytes at a time.  Also,
rearrange the code so the pure DDC bits are separate from block parse.

Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-04-06 10:40:16 +10:00
Linus Torvalds
749d229761 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9p: saving negative to unsigned char
  9p: return on mutex_lock_interruptible()
  9p: Creating files with names too long should fail with ENAMETOOLONG.
  9p: Make sure we are able to clunk the cached fid on umount
  9p: drop nlink remove
  fs/9p: Clunk the fid resulting from partial walk of the name
  9p: documentation update
  9p: Fix setting of protocol flags in v9fs_session_info structure.
2010-04-05 13:42:54 -07:00
Mark Brown
53a61d967a Merge branch 'for-2.6.34' into for-2.6.35
Conflicts due to context changes next to the backported DMA data change:
	include/sound/soc.h
2010-04-05 19:19:32 +01:00
Mark Brown
c9fbf7e070 mfd: Add WM8994 interrupt controller support
The WM8994 has an interrupt controller which supports interrupts for
both CODEC and GPIO portions of the chip. Support this using genirq,
while allowing for systems that do not have an interrupt hooked up.

Wrapper functions are provided for the IRQ request and free to simplify
the code in consumer drivers when handling cases where IRQs are not
set up.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
2010-04-05 19:18:07 +01:00
Daniel Mack
5f712b2b73 ALSA: ASoC: move dma_data from snd_soc_dai to snd_soc_pcm_stream
This fixes a memory corruption when ASoC devices are used in
full-duplex mode. Specifically for pxa-ssp code, where this pointer
is dynamically allocated for each direction and destroyed upon each
stream start.

All other platforms are fixed blindly, I couldn't even compile-test
them. Sorry for any breakage I may have caused.

[Note that this is a backported version for 2.6.34.
 Upstream commit is fd23b7dee]

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Reported-by: Sven Neumann <s.neumann@raumfeld.com>
Reported-by: Michael Hirsch <m.hirsch@raumfeld.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2010-04-05 19:14:11 +01:00
Linus Torvalds
b66696e3c0 Merge branch 'slabh' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc
* 'slabh' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc:
  eeepc-wmi: include slab.h
  staging/otus: include slab.h from usbdrv.h
  percpu: don't implicitly include slab.h from percpu.h
  kmemcheck: Fix build errors due to missing slab.h
  include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
  iwlwifi: don't include iwl-dev.h from iwl-devtrace.h
  x86: don't include slab.h from arch/x86/include/asm/pgtable_32.h

Fix up trivial conflicts in include/linux/percpu.h due to
is_kernel_percpu_address() having been introduced since the slab.h
cleanup with the percpu_up.c splitup.
2010-04-05 09:39:11 -07:00
Linus Torvalds
9e74e7c81a Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  module: add stub for is_module_percpu_address
  percpu, module: implement and use is_kernel/module_percpu_address()
  module: encapsulate percpu handling better and record percpu_size
2010-04-05 09:16:37 -07:00
Aneesh Kumar K.V
6d96d3ab7a 9p: Make sure we are able to clunk the cached fid on umount
dcache prune happen on umount. So we cannot mark the client
satus disconnect. That will prevent a 9p call to the server

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-04-05 10:37:36 -05:00
Paul Mundt
94a46d3cde Merge branch 'sh/stable-updates' 2010-04-05 12:21:09 +09:00
Tejun Heo
336f5899d2 Merge branch 'master' into export-slabh 2010-04-05 11:37:28 +09:00
Linus Torvalds
8ce42c8b7f Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf: Always build the powerpc perf_arch_fetch_caller_regs version
  perf: Always build the stub perf_arch_fetch_caller_regs version
  perf, probe-finder: Build fix on Debian
  perf/scripts: Tuple was set from long in both branches in python_process_event()
  perf: Fix 'perf sched record' deadlock
  perf, x86: Fix callgraphs of 32-bit processes on 64-bit kernels
  perf, x86: Fix AMD hotplug & constraint initialization
  x86: Move notify_cpu_starting() callback to a later stage
  x86,kgdb: Always initialize the hw breakpoint attribute
  perf: Use hot regs with software sched switch/migrate events
  perf: Correctly align perf event tracing buffer
2010-04-04 12:13:10 -07:00
Frederic Weisbecker
6cc8a7c1d8 perf: Fetch hot regs from the template caller
Trace events can be defined from a template using
DECLARE_EVENT_CLASS/DEFINE_EVENT or directly with TRACE_EVENT.

In both cases we have a template tracepoint handler, used to
record the trace, to which we pass our ftrace event instance.

In the function level, if the class is named "foo" and the event
is named "blah", we have the following chain of calls:

perf_trace_blah() -> perf_trace_templ_foo()

In the case we have several events sharing the class "blah",
we'll have multiple users of perf_trace_templ_foo(), and it
won't be inlined by the compiler. This is usually what happens
with the DECLARE_EVENT_CLASS/DEFINE_EVENT based definition.

But if perf_trace_blah() is the only caller of perf_trace_templ_foo()
there are fair chances that it will be inlined.

The problem is that we fetch the regs from perf_trace_templ_foo()
after we rewinded the frame pointer to the second caller, we want
to reach the caller of perf_trace_blah() to get the right source
of the event. And we do this by always assuming that
perf_trace_templ_foo() is not inlined. But as shown above this
is not always true. And if it is inlined we miss the first caller,
losing the most important level of precision.

We get:
	    61.31%       ls  [kernel.kallsyms]  [k] do_softirq
                         |
                         --- do_softirq
                             irq_exit
                             do_IRQ
                             common_interrupt
                            |
                            |--25.00%-- tty_buffer_request_room

Instead of:
	    61.31%       ls  [kernel.kallsyms]  [k] __do_softirq
                         |
                         --- __do_softirq
                             do_softirq
                             irq_exit
                             do_IRQ
                             common_interrupt
                            |
                            |--25.00%-- tty_buffer_request_room

To fix this, we fetch the regs from perf_trace_blah() rather than
perf_trace_templ_foo() so that we don't have to deal with inlining
surprises.

That also bring us the advantage of having the true source of the
event even if we don't have frame pointers.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
2010-04-04 15:23:07 +02:00
Dan Carpenter
f11947c7c5 ALSA: i2c: cleanup: change parameter to pointer
We actually pass an array of 7 chars not 5.
This silences a smatch warning.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2010-04-04 12:21:39 +02:00
Bjorn Helgaas
57283776b2 ACPI: pci_root: pass acpi_pci_root to arch-specific scan
The acpi_pci_root structure contains all the individual items (acpi_device,
domain, bus number) we pass to pci_acpi_scan_root(), so just pass the
single acpi_pci_root pointer directly.

This will make it easier to add _CBA support later.  For _CBA, we need the
entire downstream bus range, not just the base bus number.  We have that in
the acpi_pci_root structure, so passing the pointer makes it available to
the arch-specific code.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-04-04 00:29:53 -04:00
Bjorn Helgaas
6ad95513d6 ACPI: pci_root: save downstream bus range
Previously, we only saved the root bus number, i.e., the beginning of the
downstream bus range.  We now support IORESOURCE_BUS resources, so this
patch uses that to keep track of both the beginning and the end of the
downstream bus range.

It's important to know both the beginning and the end for supporting _CBA
(see PCI Firmware spec, rev 3.0, sec 4.1.3) and so we know the limits for
any possible PCI bus renumbering (we can't renumber downstream buses to be
outside the bus number range claimed by the host bridge).

It's clear from the spec that the bus range is supposed to be in _CRS, but
if we don't find it there, we'll assume [_BBN - 0xFF] or [0 - 0xFF].

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-04-04 00:29:41 -04:00
Eric Dumazet
1f8438a853 icmp: Account for ICMP out errors
When ip_append() fails because of socket limit or memory shortage,
increment ICMP_MIB_OUTERRORS counter, so that "netstat -s" can report
these errors.

LANG=C netstat -s | grep "ICMP messages failed"
    0 ICMP messages failed

For IPV6, implement ICMP6_MIB_OUTERRORS counter as well.

# grep Icmp6OutErrors /proc/net/dev_snmp6/*
/proc/net/dev_snmp6/eth0:Icmp6OutErrors                   	0
/proc/net/dev_snmp6/lo:Icmp6OutErrors                   	0

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 15:09:04 -07:00
James Chapman
309795f4be l2tp: Add netlink control API for L2TP
In L2TPv3, we need to create/delete/modify/query L2TP tunnel and
session contexts. The number of parameters is significant. So let's
use netlink. Userspace uses this API to control L2TP tunnel/session
contexts in the kernel.

The previous pppol2tp driver was managed using [gs]etsockopt(). This
API is retained for backwards compatibility. Unlike L2TPv2 which
carries only PPP frames, L2TPv3 can carry raw ethernet frames or other
frame types and these do not always have an associated socket
family. Therefore, we need a way to use L2TP sessions that doesn't
require a socket type for each supported frame type. Hence netlink is
used.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:05 -07:00
James Chapman
f408e0ce40 netlink: Export genl_lock() API for use by modules
This lets kernel modules which use genl netlink APIs serialize netlink
processing.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:05 -07:00
James Chapman
0d76751fad l2tp: Add L2TPv3 IP encapsulation (no UDP) support
This patch adds a new L2TPIP socket family and modifies the core to
handle the case where there is no UDP header in the L2TP
packet. L2TP/IP uses IP protocol 115. Since L2TP/UDP and L2TP/IP
packets differ in layout, the datapath packet handling code needs
changes too. Userspace uses an L2TPIP socket instead of a UDP socket
when IP encapsulation is required.

We can't use raw sockets for this because the semantics of raw sockets
don't lend themselves to the socket-per-tunnel model - we need to

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:04 -07:00
James Chapman
e0d4435f93 l2tp: Update PPP-over-L2TP driver to work over L2TPv3
This patch makes changes to the L2TP PPP code for L2TPv3.

The existing code has some assumptions about the L2TP header which are
broken by L2TPv3. Also the sockaddr_pppol2tp structure of the original
code is too small to support the increased size of the L2TPv3 tunnel
and session id, so a new sockaddr_pppol2tpv3 structure is needed. In
the socket calls, the size of this structure is used to tell if the
operation is for L2TPv2 or L2TPv3.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:04 -07:00
James Chapman
63f96072f9 ppp: Add ppp_dev_name() exported function
ppp_dev_name() gives PPP users visibility of a ppp channel's device
name. This can be used by L2TP drivers to dump the assigned PPP
interface name.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:02 -07:00
James Chapman
fd558d186d l2tp: Split pppol2tp patch into separate l2tp and ppp parts
This patch splits the pppol2tp driver into separate L2TP and PPP parts
to prepare for L2TPv3 support. In L2TPv3, protocols other than PPP can
be carried, so this split creates a common L2TP core that will handle
the common L2TP bits which protocol support modules such as PPP will
use.

Note that the existing pppol2tp module is split into l2tp_core and
l2tp_ppp by this change.

There are no feature changes here. Internally, however, there are
significant changes, mostly to handle the separation of PPP-specific
data from the L2TP session and to provide hooks in the core for
modules like PPP to access.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:02 -07:00
Jiri Pirko
22bedad3ce net: convert multicast list to list_head
Converts the list and the core manipulating with it to be the same as uc_list.

+uses two functions for adding/removing mc address (normal and "global"
 variant) instead of a function parameter.
+removes dev_mcast.c completely.
+exposes netdev_hw_addr_list_* macros along with __hw_addr_* functions for
 manipulation with lists on a sandbox (used in bonding and 80211 drivers)

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:22:15 -07:00
Jiri Pirko
a748ee2426 net: move address list functions to a separate file
+little renaming of unicast functions to be smooth with multicast ones

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:22:11 -07:00
Linus Torvalds
5e11611a5d Merge master.kernel.org:/home/rmk/linux-2.6-arm
* master.kernel.org:/home/rmk/linux-2.6-arm:
  ARM: 5965/1: Fix soft lockup in at91 udc driver
  ARM: 6006/1: ARM: Use the correct NOP size in memmove for Thumb-2 kernel builds
  ARM: 6005/1: arm: kprobes: fix register corruption with jprobes
  ARM: 6003/1: removing compilation warning from pl061.h
  ARM: 6001/1: removing compilation warning comming from clkdev.h
  ARM: 6000/1: removing compilation warning comming from <asm/irq.h>
  ARM: 5999/1: Including device.h and resource.h header files in linux/amba/bus.h
  ARM: 5997/1: ARM: Correct the VFPv3 detection
  ARM: 5996/1: ARM: Change the mandatory barriers implementation (4/4)
  ARM: 5995/1: ARM: Add L2x0 outer_sync() support (3/4)
  ARM: 5994/1: ARM: Add outer_cache_fns.sync function pointer (2/4)
  ARM: 5993/1: ARM: Move the outer_cache definitions into a separate file (1/4)
2010-04-02 19:50:11 -07:00
Linus Torvalds
24b99d1576 Merge branch 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
  Freezer: Fix buggy resume test for tasks frozen with cgroup freezer
  Freezer: Only show the state of tasks refusing to freeze
2010-04-02 19:44:42 -07:00
David Woodhouse
8626d3b432 phylib: Support phy module autoloading
We don't use the normal hotplug mechanism because it doesn't work. It will
load the module some time after the device appears, but that's not good
enough for us -- we need the driver loaded _immediately_ because otherwise
the NIC driver may just abort and then the phy 'device' goes away.

[bwh: s/phy/mdio/ in module alias, kerneldoc for struct mdio_device_id]

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-02 14:30:39 -07:00
Peter Zijlstra
371fd7e7a5 sched: Add enqueue/dequeue flags
In order to reduce the dependency on TASK_WAKING rework the enqueue
interface to support a proper flags field.

Replace the int wakeup, bool head arguments with an int flags argument
and create the following flags:

  ENQUEUE_WAKEUP - the enqueue is a wakeup of a sleeping task,
  ENQUEUE_WAKING - the enqueue has relative vruntime due to
                   having sched_class::task_waking() called,
  ENQUEUE_HEAD - the waking task should be places on the head
                 of the priority queue (where appropriate).

For symmetry also convert sched_class::dequeue() to a flags scheme.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:05 +02:00
Peter Zijlstra
0017d73509 sched: Fix TASK_WAKING vs fork deadlock
Oleg noticed a few races with the TASK_WAKING usage on fork.

 - since TASK_WAKING is basically a spinlock, it should be IRQ safe
 - since we set TASK_WAKING (*) without holding rq->lock it could
   be there still is a rq->lock holder, thereby not actually
   providing full serialization.

(*) in fact we clear PF_STARTING, which in effect enables TASK_WAKING.

Cure the second issue by not setting TASK_WAKING in sched_fork(), but
only temporarily in wake_up_new_task() while calling select_task_rq().

Cure the first by holding rq->lock around the select_task_rq() call,
this will disable IRQs, this however requires that we push down the
rq->lock release into select_task_rq_fair()'s cgroup stuff.

Because select_task_rq_fair() still needs to drop the rq->lock we
cannot fully get rid of TASK_WAKING.

Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:03 +02:00
Oleg Nesterov
9084bb8246 sched: Make select_fallback_rq() cpuset friendly
Introduce cpuset_cpus_allowed_fallback() helper to fix the cpuset problems
with select_fallback_rq(). It can be called from any context and can't use
any cpuset locks including task_lock(). It is called when the task doesn't
have online cpus in ->cpus_allowed but ttwu/etc must be able to find a
suitable cpu.

I am not proud of this patch. Everything which needs such a fat comment
can't be good even if correct. But I'd prefer to not change the locking
rules in the code I hardly understand, and in any case I believe this
simple change make the code much more correct compared to deadlocks we
currently have.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100315091027.GA9155@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:03 +02:00
Oleg Nesterov
6a1bdc1b57 sched: _cpu_down(): Don't play with current->cpus_allowed
_cpu_down() changes the current task's affinity and then recovers it at
the end. The problems are well known: we can't restore old_allowed if it
was bound to the now-dead-cpu, and we can race with the userspace which
can change cpu-affinity during unplug.

_cpu_down() should not play with current->cpus_allowed at all. Instead,
take_cpu_down() can migrate the caller of _cpu_down() after __cpu_disable()
removes the dying cpu from cpu_online_mask.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100315091023.GA9148@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:03 +02:00
Oleg Nesterov
897f0b3c3f sched: Kill the broken and deadlockable cpuset_lock/cpuset_cpus_allowed_locked code
This patch just states the fact the cpusets/cpuhotplug interaction is
broken and removes the deadlockable code which only pretends to work.

- cpuset_lock() doesn't really work. It is needed for
  cpuset_cpus_allowed_locked() but we can't take this lock in
  try_to_wake_up()->select_fallback_rq() path.

- cpuset_lock() is deadlockable. Suppose that a task T bound to CPU takes
  callback_mutex. If cpu_down(CPU) happens before T drops callback_mutex
  stop_machine() preempts T, then migration_call(CPU_DEAD) tries to take
  cpuset_lock() and hangs forever because CPU is already dead and thus
  T can't be scheduled.

- cpuset_cpus_allowed_locked() is deadlockable too. It takes task_lock()
  which is not irq-safe, but try_to_wake_up() can be called from irq.

Kill them, and change select_fallback_rq() to use cpu_possible_mask, like
we currently do without CONFIG_CPUSETS.

Also, with or without this patch, with or without CONFIG_CPUSETS, the
callers of select_fallback_rq() can race with each other or with
set_cpus_allowed() pathes.

The subsequent patches try to to fix these problems.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100315091003.GA9123@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:12:01 +02:00
Ingo Molnar
c9494727cf Merge branch 'linus' into sched/core
Merge reason: update to latest upstream

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 20:03:08 +02:00
Ingo Molnar
ec5e61aabe Merge branch 'perf/urgent' into perf/core
Conflicts:
	arch/x86/kernel/cpu/perf_event.c

Merge reason: Resolve the conflict, pick up fixes

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-02 19:38:10 +02:00
Ingo Molnar
50d11d190a Merge branch 'perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/urgent 2010-04-02 19:29:17 +02:00
Divyesh Shah
9195291e5f blkio: Increment the blkio cgroup stats for real now
We also add start_time_ns and io_start_time_ns fields to struct request
here to record the time when a request is created and when it is
dispatched to device. We use ns uints here as ms and jiffies are
not very useful for non-rotational media.

Signed-off-by: Divyesh Shah<dpshah@google.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-02 08:44:37 +02:00
Jens Axboe
ed6b6dc7c1 Merge branch 'for-linus' into for-2.6.35 2010-04-02 08:43:33 +02:00
YOSHIFUJI Hideaki / 吉藤英明
bd2c77a0a7 ipv6 fib: Make rt6_info{} more cache-line aware.
The head element of rt6_info{} is dst_entry{}, and
IPv6 specific elements follow.

Because elements at the end of dst_entry{} are frequently
updated, it is not good to put frequently-used static
elements, such as rt6i_idev, rt6i_dst or rt6i_flags in the
same cache line.

On the other hand, fib6_table, rt6i_node or rt6i_gateway are
rarely used, so it is okay to stay in the same cache line.

Let's rearrange rt6_info{}.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-01 18:41:41 -07:00
Eric Dumazet
5d944c640b gen_estimator: deadlock fix
One of my test machine got a deadlock during "tc" sessions,
adding/deleting classes & filters, using traffic estimators.

After some analysis, I believe we have a potential use after free case
in est_timer() :

spin_lock(e->stats_lock); << HERE >>
read_lock(&est_lock);
if (e->bstats == NULL)   << TEST >>
	goto skip;

Test is done a bit late, because after estimator is killed, and before
rcu grace period elapsed, we might already have freed/reuse memory where
e->stats_locks points to (some qdisc->q.lock)

A possible fix is to respect a rcu grace period at Qdisc dismantle time.

On 64bit, sizeof(struct Qdisc) is exactly 192 bytes. Adding 16 bytes to
it (for struct rcu_head) is a problem because it might change
performance, given QDISC_ALIGNTO is 32 bytes.

This is why I also change QDISC_ALIGNTO to 64 bytes, to satisfy most
current alignment requirements.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-01 18:38:48 -07:00
Yinghai Lu
042be38e61 ibft, x86: Change reserve_ibft_region() to find_ibft_region()
This allows arch code could decide the way to reserve the ibft.

And we should reserve ibft as early as possible, instead of BOOTMEM
stage, in case the table is in RAM range and is not reserved by BIOS
(this will often be the case.)

Move to just after find_smp_config().

Also when CONFIG_NO_BOOTMEM=y, We will not have reserve_bootmem() anymore.

-v2: fix typo about ibft pointed by Konrad Rzeszutek Wilk <konrad@darnok.org>

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4BB510FB.80601@kernel.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Jones <pjones@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
CC: Jan Beulich <jbeulich@novell.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-04-01 16:12:48 -07:00
Linus Torvalds
42be79e37e Merge branch 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (76 commits)
  drm/radeon/kms: enable ACPI powermanagement mode on radeon gpus.
  drm/radeon/kms: rs400/480 should set common registers.
  drm/radeon/kms: add sanity check to wptr.
  drm/radeon/kms/evergreen: get DP working
  drm/radeon/kms: add hw_i2c module option
  drm/radeon/kms: use new pre/post_xfer i2c bit algo hooks
  drm/radeon/kms: disable MSI on IGP chips
  drm/radeon/kms: display watermark updates (v2)
  drm/radeon/kms/dp: disable training pattern on the sink at the end of link training
  drm/radeon/kms: minor fixes for eDP with LCD* device tags (v2)
  drm/radeon/kms/dp: remove extraneous training complete call
  drm/radeon/kms/atom: minor fixes to transmitter setup
  drm/radeon/kms: Only restrict BO to visible VRAM size when pinning to VRAM.
  drm: fix build error when SYSRQ is disabled
  drm/radeon/kms: fix macbookpro connector quirk
  drm/radeon/r6xx/r7xx: further safe reg clean up
  drm/radeon: bump the UMS driver version for r6xx/r7xx const buffer support
  drm/radeon/kms: bump the version for r6xx/r7xx const buffer support
  drm/radeon/r6xx/r7xx: CS parser fixes
  drm/radeon/kms: fix some typos in r6xx/r7xx hpd setup
  ...

Fix up MSI-related conflicts in drivers/gpu/drm/radeon/radeon_irq_kms.c
2010-04-01 09:19:42 -07:00
Herbert Xu
6072f7491f ide: Requeue request after DMA timeout
I noticed that my KVM virtual machines were experiencing IDE
issues resulting in processes stuck on waiting for buffers to
complete.

The root cause is of course race conditions in the ancient qemu
backend that I'm using.  However, the fact that the guest isn't
recovering is a bug.

I've tracked it down to the change made last year to dequeue
requests at the start rather than at the end in the IDE layer.

commit 8f6205cd57
Author: Tejun Heo <tj@kernel.org>
Date:   Fri May 8 11:53:59 2009 +0900

    ide: dequeue in-flight request

The problem is that the function ide_dma_timeout_retry does not
requeue the current request, causing one request to be lost for
each DMA timeout.

This patch fixes this by requeueing the request.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-01 01:31:13 -07:00