Impact: avoid timer IRQ hanging slow systems

While using the function graph tracer on a virtualized system, the
hrtimer_interrupt can hang the system on an infinite loop.

This can be caused in several situations:

 - the hardware is very slow and HZ is set too high

 - something intrusive is slowing the system down (tracing under emulation)

... and the next clock events to program are always before the current time.

This patch implements a reasonable compromise: if such a situation is
detected, we share the CPUs time in 1/4 to process the hrtimer interrupts.
This is enough to let the system running without serious starvation.

It has been successfully tested under VirtualBox with 1000 HZ and 100 HZ
with function graph tracer launched. On both cases, the clock events were
increased until about 25 ms periodic ticks, which means 40 HZ.

So we change a hard to debug hang into a warning message and a system that
still manages to limp along.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
  cifs: make sure we allocate enough storage for socket address
  [CIFS] Make socket retry timeouts consistent between blocking and nonblocking cases
  [CIFS] some cleanup to dir.c prior to addition of posix_open
  [CIFS] revalidate parent inode when rmdir done within that directory
  [CIFS] Rename md5 functions to avoid collision with new rt modules
  cifs: turn smb_send into a wrapper around smb_sendv

Commit e57db7bd (SATA Sil: Blacklist system that spins off disks during ACPI power off)
 breaks build like the following, in both cases when CONFIG_DMI set or not.

        drivers/ata/sata_sil.c: In function 'sil_broken_system_poweroff':
        drivers/ata/sata_sil.c:713: error: implicit declaration of function 'dmi_first_match'
        drivers/ata/sata_sil.c:713: warning: initialization makes pointer from integer without a cast

  sata_sil.c should include dmi.h
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

btrfs requires version 0.18 of its tools, and squashfs requires 4.0.
ext3 should use and ext4 requires v1.41.4 of e2fsprogs.
Signed-off-by: Bill Nottingham <notting@redhat.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
cc: Ted Tso <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I don't think emacs understands tilde expansion, so use
"expand-file-name" to do that.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With the previous Emacs tips example the kernel style was made available
for files in the kernel-tree only. This patch updates the tip to add a
separate cc-mode indent style ("linux-tabs-only"). This makes it easy to
switch between different indent styles and also makes the kernel style
easily available for any filetype mode (c++, awk, ...) that is managed
by the Emacs cc-mode.
Signed-off-by: Teemu Likonen <tlikonen@iki.fi>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Move DMA-mapping.txt to Documentation/PCI/.

DMA-mapping.txt was supposed to be moved from Documentation/ to
Documentation/PCI/.  The 00-INDEX files in those two directories
were updated, along with a few other text files, but the file
itself somehow escaped being moved, so move it and update more
text files and source files with its new location.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
cc:	Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging-2.6:
  Staging: poch: fix verification of memory area
  Staging: usbip: usbip_start_threads(): handle kernel_thread failure
  staging: agnx: drivers/staging/agnx/agnx.h needs <linux/io.h>
  Staging: android: task_get_unused_fd_flags: fix the wrong usage of tsk->signal
  Staging: android: Add lowmemorykiller documentation.
  Staging: android: fix build error on 64bit boxes
  Staging: android: timed_gpio: Fix build to build on kernels after 2.6.25.
  Staging: android: binder: fix arm build errors
  Staging: meilhaus: fix Kbuild
  Staging: comedi: fix Kbuild

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  driver-core: fix kernel-doc parameter name
  UIO: Add missing documentation of features added recently
  Sync patch for jp_JP/stable_kernel_rules.txt

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ASoC: OMAP: Initialize XCCR and RCCR registers in McBSP DAI driver
  ASoC: Fix null string usage with WM8753 DAIs
  ALSA: hda - add another MacBook Pro 4, 1 subsystem ID
  ALSA: hda - Fix compile warning with CONFIG_SND_JACK=n
  ALSA: hda - Add quirk for HP DV6700 laptop
  ALSA: hda - Fix PCM reference NID for STAC/IDT analog outputs

* 'linux-next' of git://git.infradead.org/ubi-2.6:
  UBI: allow direct user-space I/O
  UBI: fix resource de-allocation
  UBI: remove unused variable
  UBI: use nicer 64-bit math
  UBI: add ioctl compatibility
  UBI: constify file operations
  UBI: allow all ioctls
  UBI: remove unnecessry header inclusion
  UBI: improve ioctl commentaries
  UBI: add ioctl for is_mapped operation
  UBI: add ioctl for unmap operation
  UBI: add ioctl for map operation

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: document difference between hid_blacklist and hid_ignore_list
  HID: add antec-branded soundgraph imon devices to blacklist
  HID: fix reversed logic in disconnect testing of hiddev
  HID: adjust report descriptor fixup for MS 1028 receiver

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  lguest: Fix a memory leak with the lg object during launcher close
  lguest: disable the FORTIFY for lguest.
  lguest: typos fix

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  ieee1394: sbp2: add workarounds for 2nd and 3rd generation iPods
  firewire: sbp2: add workarounds for 2nd and 3rd generation iPods
  firewire: sbp2: fix DMA mapping leak on the failure path
  firewire: sbp2: define some magic numbers as macros
  firewire: sbp2: fix payload limit at S1600 and S3200
  ieee1394: sbp2: don't assume zero model_id or firmware_revision if there is none
  ieee1394: sbp2: fix payload limit at S1600 and S3200
  ieee1394: sbp2: update a help string
  ieee1394: support for speeds greater than S800
  firewire: core: optimize card shutdown
  ieee1394: ohci1394: increase AT req. retries, fix ack_busy_X from Panasonic camcorders and others
  firewire: ohci: increase AT req. retries, fix ack_busy_X from Panasonic camcorders and others
  firewire: ohci: change "context_stop: still active" log message
  firewire: keep highlevel drivers attached during brief connection loss
  firewire: unnecessary BM delay after generation rollover
  firewire: insist on successive self ID complete events

s/unlock/lock/

Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12575Reported-by: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Airlie <airlied@linux.ie>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Eric Anholt <eric@anholt.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Linus suggested to put limits where the money is, and max_user_watches
already does that w/out the need of max_user_instances.  That has the
advantage to mitigate the potential DoS while allowing pretty generous
default behavior.

Allowing top 4% of low memory (per user) to be allocated in epoll watches,
we have:

LOMEM    MAX_WATCHES (per user)
512MB    ~178000
1GB      ~356000
2GB      ~712000

A box with 512MB of lomem, will meet some challenge in hitting 180K
watches, socket buffers math teaches us.  No more max_user_instances
limits then.
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Michael Kerrisk <mtk.manpages@googlemail.com>
Cc: Bron Gondwana <brong@fastmail.fm>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If the initial state is not set when the input device is set up, the first
docking event after the module is loaded will be lost.
Signed-off-by: Frans Pop <elendil@planet.nl>
Acked-by: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MacPro 3 have more temperature sensors than the previous MacPro's also the
sensor THTG has been removed.  This patch add supports for the newer
temperature sensors in the MacPro3.
Signed-off-by: Bharath Ramesh <bramesh@vt.edu>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Bump hpilo module version to indicate that the open/close bug is fixed.
Signed-off-by: David Altobelli <david.altobelli@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

root_count was being incremented in cgroup_get_sb() after all error
checking was complete, but decremented in cgroup_kill_sb(), which can be
called on a superblock that we gave up on due to an error.  This patch
changes cgroup_kill_sb() to only decrement root_count if the root was
previously linked into the list of roots.
Signed-off-by: Paul Menage <menage@google.com>
Tested-by: Serge Hallyn <serue@us.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

css_tryget() and cgroup_clear_css_refs() contain polling loops; these
loops should have cpu_relax calls in them to reduce cross-cache traffic.
Signed-off-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I fixed a bug in cgroup_clone() in Linus' tree in commit 7b574b7b
("cgroups: fix a race between cgroup_clone and umount") without noticing
there was a cleanup patch in -mm tree that should be rebased (now commit
104cbd5, "cgroups: use task_lock() for access tsk->cgroups safe in
cgroup_clone()"), thus resulted in lock inconsistency.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The commit "alpha: teach the compiler that BUG doesn't return"
(ed6b9b97) moved the asm code into inline
function which takes __FILE__ and __LINE__ as arguments.  This violates
asm constrains there ("i" - an immediate operand with constant value), so
that compile may result in warning or error, depending on compiler
version.

Just adding an infinite loop to the BUG() is sufficient.
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

- jensen build: fix conflicting declarations for pci_alloc_consistent()
  and undefined virt_to_phys();

- SMP: arch/alpha/kernel/smp.c:124: warning: passing argument 2
       of '__cpu_test_and_set' discards qualifiers from pointer target type
  Interestingly, this only happens with gcc-4.2; gcc <= 4.1 and gcc-4.3
  are OK. Fixed with extra assignment.
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Convert OSF syscalls and add alpha specific SYSCALL_ALIAS() macro.
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

N_POSSIBLE doesn't means there is memory...and force_empty can
visit invalid node which have no pgdat.

To visit all valid nodes, N_HIGH_MEMORY should be used.
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Error was introduced in commit fe8e4e03 ("hp-wmi: handle
rfkill_register() failure").
Signed-off-by: Frans Pop <elendil@planet.nl>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Acked-by: Matthew Garrett <mjg@redhat.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Considering the recently found problem "memcg: fix refcnt handling at
swapoff", it's better to mention swapoff behavior in the memcg_test
document.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Now, at swapoff, even while try_charge() fails, commit is executed.  This
is a bug which turns the refcnt of cgroup_subsys_state negative.
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Tested-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix request-already-requested handling in gpio_request().
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The lifetime of struct cgroup and struct mem_cgroup is different and
mem_cgroup has its own reference count for handling references from
swap_cgroup.

This causes strange problem that the parent mem_cgroup dies while child
mem_cgroup alive, and this problem causes a bug in case of
use_hierarchy==1 because res_counter_uncharge climbs up the tree.

This patch is for avoiding it by getting the parent at create, and putting
it at freeing.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by; KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Now, cgrp->sibling is handled under hierarchy mutex.
error route should do so, too.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Acked-by Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Define kprobes related data structures even if CONFIG_KPROBES is not set.
This fixes compilation errors which occur if CONFIG_KPROBES is not set, in
kprobe using modules.

[akpm@linux-foundation.org: fix build for non-kprobes-supporting architectures]
Reviewed-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Clean up the stale DBUG_ON checks and add a couple new ones.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

If the bte copy fails, the attempt to retrieve payloads merely returns a
null pointer deref and not NULL as was expected.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The clearing of the msg->flags needs a barrier between it and the notify
of the channel threads that the messages are cleaned and ready for use.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Dean Nelson <dcn@sgi.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

As of commit ba470de4 ("map: handle
mlocked pages during map, remap, unmap") we now use the 'vma' variable
at the end of mmap_region() to handle the page-in of newly mapped
mlocked pages.

However, if we merged adjacent vma's together, the vma we're using may
be stale.  We historically consciously avoided using it after the merge
operation, but that got overlooked when redoing the locked page
handling.

This commit simplifies mmap_region() by doing any vma merges early,
avoiding the issue entirely, and 'vma' will always be valid.  As pointed
out by Hugh Dickins, this depends on any drivers that change the page
offset of flags to have set one of the VM_SPECIAL bits (so that they
cannot trigger the early merge logic), but that's true in general.
Reported-and-tested-by: Maksim Yevmenkin <maksim.yevmenkin@gmail.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix a memory leak identified by Rusty Russell during LCA09 by
kfree'ing the lg object instead of just clearing it when the
launcher closes.
Signed-off-by: Mark Wallis <mwallis@serialmonkey.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>