21499 Commits

Author SHA1 Message Date
f0f9deae9e netpoll: Disable IRQ around RCU dereference in netpoll_rx
We cannot use rcu_dereference_bh safely in netpoll_rx as we may
be called with IRQs disabled.  We could however simply disable
IRQs as that too causes BH to be disabled and is safe in either
case.

Thanks to John Linville for discovering this bug and providing
a patch.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-17 16:55:03 -07:00
053d8f6622 Merge branch 'vhost-net' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost 2010-09-09 21:59:51 -07:00
d56557af19 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: bus speed strings should be const
  PCI hotplug: Fix build with CONFIG_ACPI unset
  PCI: PCIe: Remove the port driver module exit routine
  PCI: PCIe: Move PCIe PME code to the pcie directory
  PCI: PCIe: Disable PCIe port services during port initialization
  PCI: PCIe: Ask BIOS for control of all native services at once
  ACPI/PCI: Negotiate _OSC control bits before requesting them
  ACPI/PCI: Do not preserve _OSC control bits returned by a query
  ACPI/PCI: Make acpi_pci_query_osc() return control bits
  ACPI/PCI: Reorder checks in acpi_pci_osc_control_set()
  PCI: PCIe: Introduce commad line switch for disabling port services
  PCI: PCIe AER: Introduce pci_aer_available()
  x86/PCI: only define pci_domain_nr if PCI and PCI_DOMAINS are set
  PCI: provide stub pci_domain_nr function for !CONFIG_PCI configs
2010-09-07 16:00:17 -07:00
a44a553f82 Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  powerpc/pseries: Correct rtas_data_buf locking in dlpar code
  powerpc/85xx: Add P1021 PCI IDs and quirks
  arch/powerpc/sysdev/qe_lib/qe.c: Add of_node_put to avoid memory leak
  arch/powerpc/platforms/83xx/mpc837x_mds.c: Add missing iounmap
  fsl_rio: fix compile errors
  powerpc/85xx: Fix compile issue with p1022_ds due to lmb rename to memblock
  powerpc/85xx: Fix compilation of mpc85xx_mds.c
  powerpc: Don't use kernel stack with translation off
  powerpc/perf_event: Reduce latency of calling perf_event_do_pending
  powerpc/kexec: Adds correct calling convention for kexec purgatory
2010-09-07 14:34:37 -07:00
ce7db282a3 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:
  percpu: fix a mismatch between code and comment
  percpu: fix a memory leak in pcpu_extend_area_map()
  percpu: add __percpu notations to UP allocator
  percpu: handle __percpu notations in UP accessors
2010-09-07 14:08:37 -07:00
cd4d4fc413 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: use zalloc_cpumask_var() for gcwq->mayday_mask
  workqueue: fix GCWQ_DISASSOCIATED initialization
  workqueue: Add a workqueue chapter to the tracepoint docbook
  workqueue: fix cwq->nr_active underflow
  workqueue: improve destroy_workqueue() debuggability
  workqueue: mark lock acquisition on worker_maybe_bind_and_lock()
  workqueue: annotate lock context change
  workqueue: free rescuer on destroy_workqueue
2010-09-07 14:08:17 -07:00
608a5ffc3e Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
  tty: fix tty_line must not be equal to number of allocated tty pointers in tty driver
  serial: bfin_sport_uart: restore transmit frame sync fix
  serial: fix port type conflict between NS16550A & U6_16550A
  MAINTAINERS: orphan isicom
  vt: Fix console corruption on driver hand-over.
2010-09-07 14:04:09 -07:00
f8f235e5bb agp/intel: Fix cache control for Sandybridge
Sandybridge GTT has new cache control bits in PTE, which controls
graphics page cache in LLC or LLC/MLC, so we need to extend the mask
function to respect the new bits.

And set cache control to always LLC only by default on Gen6.

Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Cc: stable@kernel.org
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
2010-09-07 11:16:43 +01:00
73457f0f83 cgroups: fix API thinko
cgroup_attach_task_current_cg API that have upstream is backwards: we
really need an API to attach to the cgroups from another process A to
the current one.

In our case (vhost), a priveledged user wants to attach it's task to cgroups
from a less priveledged one, the API makes us run it in the other
task's context, and this fails.

So let's make the API generic and just pass in 'from' and 'to' tasks.
Add an inline wrapper for cgroup_attach_task_current_cg to avoid
breaking bisect.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Paul Menage <menage@google.com>
2010-09-05 17:01:37 +03:00
71cad05549 serial: fix port type conflict between NS16550A & U6_16550A
Bug seen by Dr. David Alan Gilbert with sparse

Signed-off-by: Philippe Langlais <philippe.langlais@stericsson.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-09-03 17:29:04 -07:00
a28dec2f26 powerpc/85xx: Add P1021 PCI IDs and quirks
This is needed for proper PCI-E support on P1021 SoCs.

Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2010-08-31 16:44:24 -05:00
30c0f6a049 Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify
* 'for-linus' of git://git.infradead.org/users/eparis/notify:
  fsnotify: drop two useless bools in the fnsotify main loop
  fsnotify: fix list walk order
  fanotify: Return EPERM when a process is not privileged
  fanotify: resize pid and reorder structure
  fanotify: drop duplicate pr_debug statement
  fanotify: flush outstanding perm requests on group destroy
  fsnotify: fix ignored mask handling between inode and vfsmount marks
  fanotify: add MAINTAINERS entry
  fsnotify: reset used_inode and used_vfsmount on each pass
  fanotify: do not dereference inode_mark when it is unset
2010-08-28 14:11:04 -07:00
06f01e73ef Merge branch 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
  vgaarb: Wrap vga_(get|put) in CONFIG_VGA_ARB
  drm/radeon/kms: add missing scratch update in dp_detect
  drm/modes: Fix CVT-R modeline generation
  drm: fix regression in drm locking since BKL removal.
  drm/radeon/kms: remove stray radeon_i2c_destroy
  drm: mm: fix range restricted allocations
  drm/nouveau: drop drm_global_mutex before sleeping in submission path
  drm: export drm_global_mutex for drivers to use
  drm/nv20: Don't use pushbuf calls on the original nv20.
  drm/nouveau: Fix TMDS on some DCB1.5 boards.
  drm/nouveau: Fix backlight control on PPC machines with an internal TMDS panel.
  drm/nv30: Apply modesetting to the correct slave encoder
  drm/nouveau: Use a helper function to match PCI device/subsystem IDs.
  drm/nv50: add dcb type 14 to enum to prevent compiler complaint
2010-08-28 14:08:38 -07:00
bad849b3dc NOMMU: Stub out vm_get_page_prot() if there's no MMU
Stub out vm_get_page_prot() if there's no MMU.

This was added by commit 804af2cf6e7a ("[AGPGART] remove private page
protection map") and is used in commit c07fbfd17e61 ("fbmem: VM_IO set,
but not propagated") in the fbmem video driver, but the function doesn't
exist on NOMMU, resulting in an undefined symbol at link time.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-28 14:01:03 -07:00
2637d139fb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: pxa27x_keypad - remove input_free_device() in pxa27x_keypad_remove()
  Input: mousedev - fix regression of inverting axes
  Input: uinput - add devname alias to allow module on-demand load
  Input: hil_kbd - fix compile error
  USB: drop tty argument from usb_serial_handle_sysrq_char()
  Input: sysrq - drop tty argument form handle_sysrq()
  Input: sysrq - drop tty argument from sysrq ops handlers
2010-08-28 13:55:31 -07:00
0fb85621df fanotify: resize pid and reorder structure
resize pid and reorder the fanotify_event_metadata so it is naturally
aligned and we can work towards dropping the packed attributed

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@sophos.com>
Cc: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Eric Paris <eparis@redhat.com>
2010-08-27 19:54:09 -04:00
04cbe1de6f vgaarb: Wrap vga_(get|put) in CONFIG_VGA_ARB
Fix link failure without the vga arbitrator.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-08-27 09:10:44 +10:00
8a2e8e5dec workqueue: fix cwq->nr_active underflow
cwq->nr_active is used to keep track of how many work items are active
for the cpu workqueue, where 'active' is defined as either pending on
global worklist or executing.  This is used to implement the
max_active limit and workqueue freezing.  If a work item is queued
after nr_active has already reached max_active, the work item doesn't
increment nr_active and is put on the delayed queue and gets activated
later as previous active work items retire.

try_to_grab_pending() which is used in the cancellation path
unconditionally decremented nr_active whether the work item being
cancelled is currently active or delayed, so cancelling a delayed work
item makes nr_active underflow.  This breaks max_active enforcement
and triggers BUG_ON() in destroy_workqueue() later on.

This patch fixes this bug by adding a flag WORK_STRUCT_DELAYED, which
is set while a work item in on the delayed list and making
try_to_grab_pending() decrement nr_active iff the work item is
currently active.

The addition of the flag enlarges cwq alignment to 256 bytes which is
getting a bit too large.  It's scheduled to be reduced back to 128
bytes by merging WORK_STRUCT_PENDING and WORK_STRUCT_CWQ in the next
devel cycle.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Johannes Berg <johannes@sipsolutions.net>
2010-08-25 10:33:56 +02:00
75fb60f26b ACPI/PCI: Negotiate _OSC control bits before requesting them
It is possible that the BIOS will not grant control of all _OSC
features requested via acpi_pci_osc_control_set(), so it is
recommended to negotiate the final set of _OSC features with the
query flag set before calling _OSC to request control of these
features.

To implement it, rework acpi_pci_osc_control_set() so that the caller
can specify the mask of _OSC control bits to negotiate and the mask
of _OSC control bits that are absolutely necessary to it.  Then,
acpi_pci_osc_control_set() will run _OSC queries in a loop until
the mask of _OSC control bits returned by the BIOS is equal to the
mask passed to it.  Also, before running the _OSC request
acpi_pci_osc_control_set() will check if the caller's required
control bits are present in the final mask.

Using this mechanism we will be able to avoid situations in which the
BIOS doesn't grant control of certain _OSC features, because they
depend on some other _OSC features that have not been requested.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2010-08-24 13:44:40 -07:00
8ca3eb0809 guard page for stacks that grow upwards
pa-risc and ia64 have stacks that grow upwards. Check that
they do not run into other mappings. By making VM_GROWSUP
0x0 on architectures that do not ever use it, we can avoid
some unpleasant #ifdefs in check_stack_guard_page().

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-24 12:13:20 -07:00
e41e704bc4 workqueue: improve destroy_workqueue() debuggability
Now that the worklist is global, having works pending after wq
destruction can easily lead to oops and destroy_workqueue() have
several BUG_ON()s to catch these cases.  Unfortunately, BUG_ON()
doesn't tell much about how the work became pending after the final
flush_workqueue().

This patch adds WQ_DYING which is set before the final flush begins.
If a work is requested to be queued on a dying workqueue,
WARN_ON_ONCE() is triggered and the request is ignored.  This clearly
indicates which caller is trying to queue a work on a dying workqueue
and keeps the system working in most cases.

Locking rule comment is updated such that the 'I' rule includes
modifying the field from destruction path.

Signed-off-by: Tejun Heo <tj@kernel.org>
2010-08-24 18:01:32 +02:00
6d87f207c0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  kobject_uevent: fix typo in comments
  firmware_class: fix typo in error path
  kobject: Break the kobject namespace defs into their own header
2010-08-24 00:21:02 -07:00
d20de76354 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (29 commits)
  ARM: imx: fix build failure concerning otg/ulpi
  USB: ftdi_sio: add product ID for Lenz LI-USB
  USB: adutux: fix misuse of return value of copy_to_user()
  USB: iowarrior: fix misuse of return value of copy_to_user()
  USB: xHCI: update ring dequeue pointer when process missed tds
  USB: xhci: Remove buggy assignment in next_trb()
  USB: ftdi_sio: Add ID for Ionics PlugComputer
  USB: serial: io_ti.c: don't return 0 if writing the download record failed
  USB: otg: twl4030: fix wrong assumption of starting state
  USB: gadget: Return -ENOMEM on memory allocation failure
  USB: gadget: fix composite kernel-doc warnings
  USB: ssu100: set tty_flags in ssu100_process_packet
  USB: ssu100: add disconnect function for ssu100
  USB: serial: export symbol usb_serial_generic_disconnect
  USB: ssu100: rework logic for TIOCMIWAIT
  USB: ssu100: add register parameter to ssu100_setregister
  USB: ssu100: remove duplicate #defines in ssu100
  USB: ssu100: refine process_packet in ssu100
  USB: ssu100: add locking for port private data in ssu100
  USB: r8a66597-udc: return -ENOMEM if kzalloc() fails
  ...
2010-08-24 00:20:44 -07:00
d187abb9a8 USB: gadget: fix composite kernel-doc warnings
Warning(include/linux/usb/composite.h:284): No description found for parameter 'disconnect'
Warning(drivers/usb/gadget/composite.c:744): No description found for parameter 'c'
Warning(drivers/usb/gadget/composite.c:744): Excess function parameter 'cdev' description in 'usb_string_ids_n'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-23 20:50:16 -07:00
d1b113bb02 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: (27 commits)
  netfilter: fix CONFIG_COMPAT support
  isdn/avm: fix build when PCMCIA is not enabled
  header: fix broken headers for user space
  e1000e: don't check for alternate MAC addr on parts that don't support it
  e1000e: disable ASPM L1 on 82573
  ll_temac: Fix poll implementation
  netxen: fix a race in netxen_nic_get_stats()
  qlnic: fix a race in qlcnic_get_stats()
  irda: fix a race in irlan_eth_xmit()
  net: sh_eth: remove unused variable
  netxen: update version 4.0.74
  netxen: fix inconsistent lock state
  vlan: Match underlying dev carrier on vlan add
  ibmveth: Fix opps during MTU change on an active device
  ehea: Fix synchronization between HW and SW send queue
  bnx2x: Update bnx2x version to 1.52.53-4
  bnx2x: Fix PHY locking problem
  rds: fix a leak of kernel memory
  netlink: fix compat recvmsg
  netfilter: fix userspace header warning
  ...
2010-08-23 18:30:30 -07:00
8488a38f4d kobject: Break the kobject namespace defs into their own header
Break the kobject namespace defs into their own header to avoid a header file
inclusion ordering problem between linux/sysfs.h and linux/kobject.h.

This fixes the build breakage on older versions of gcc.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-23 18:12:46 -07:00
09cd2b99c6 header: fix broken headers for user space
__packed is only defined in kernel space, so we should use
__attribute__((packed)) for the code shared between kernel and user space.

Two __attribute() annotations are replaced with __attribute__() too.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-22 21:15:39 -07:00
2eebf582c9 fanotify: flush outstanding perm requests on group destroy
When an fanotify listener is closing it may cause a deadlock between the
listener and the original task doing an fs operation.  If the original task
is waiting for a permissions response it will be holding the srcu lock.  The
listener cannot clean up and exit until after that srcu lock is syncronized.
Thus deadlock.  The fix introduced here is to stop accepting new permissions
events when a listener is shutting down and to grant permission for all
outstanding events.  Thus the original task will eventually release the srcu
lock and the listener can complete shutdown.

Reported-by: Andreas Gruenbacher <agruen@suse.de>
Cc: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Eric Paris <eparis@redhat.com>
2010-08-22 20:28:16 -04:00
bc584c5107 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  slab: fix object alignment
  slub: add missing __percpu markup in mm/slub_def.h
2010-08-22 10:08:52 -07:00
297c5eee37 mm: make the vma list be doubly linked
It's a really simple list, and several of the users want to go backwards
in it to find the previous vma.  So rather than have to look up the
previous entry with 'find_vma_prev()' or something similar, just make it
doubly linked instead.

Tested-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-21 08:49:21 -07:00
8905aaafb4 Input: uinput - add devname alias to allow module on-demand load
Recent modprobe and udev versions allow to create device nodes
for modules which are not loaded. Only the first access will cause
the in-kernel module loader to pull-in the module. Systems which
never access the device node will not needlessly load the module,
and no longer need init scripts or other facilities to unconditionally
load it.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-08-21 00:37:40 -07:00
6ee9f4b4af USB: drop tty argument from usb_serial_handle_sysrq_char()
Since handle_sysrq() does not take tty as argument anymore we can
drop it from usb_serial_handle_sysrq_char() as well.

Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-08-21 00:37:39 -07:00
f335397d17 Input: sysrq - drop tty argument form handle_sysrq()
Sysrq operations do not accept tty argument anymore so no need to pass
it to us.

[Stephen Rothwell <sfr@canb.auug.org.au>: fix build breakage in drm code
 caused by sysrq using bool but not including linux/types.h]

[Sachin Sant <sachinp@in.ibm.com>: fix build breakage in s390 keyboadr
 driver]

Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-08-21 00:34:45 -07:00
b35de43b31 kfifo: implement missing __kfifo_skip_r()
kfifo_skip() is currently broken, due to the missing of the internal
helper function.  Add it.

Signed-off-by: Andrea Righi <arighi@develer.com>
Cc: Greg KH <greg@kroah.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-20 09:34:54 -07:00
1495cc9df4 Input: sysrq - drop tty argument from sysrq ops handlers
Noone is using tty argument so let's get rid of it.

Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-08-19 22:07:06 -07:00
e243f5b6de netfilter: fix userspace header warning
"make headers_check" issued the following warning:

  CHECK   include/linux/netfilter (64 files)
usr/include/linux/netfilter/xt_ipvs.h:19: found __[us]{8,16,32,64} type without #include <linux/types.h>

Fix this by as suggested including linux/types.h.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-18 23:34:26 -07:00
a49f37eed2 net: add Fast Ethernet driver for PXA168.
Signed-off-by: Sachin Sanap <ssanap@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-18 23:30:42 -07:00
145c3ae46b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  fs: brlock vfsmount_lock
  fs: scale files_lock
  lglock: introduce special lglock and brlock spin locks
  tty: fix fu_list abuse
  fs: cleanup files_lock locking
  fs: remove extra lookup in __lookup_hash
  fs: fs_struct rwlock to spinlock
  apparmor: use task path helpers
  fs: dentry allocation consolidation
  fs: fix do_lookup false negative
  mbcache: Limit the maximum number of cache entries
  hostfs ->follow_link() braino
  hostfs: dumb (and usually harmless) tpyo - strncpy instead of strlcpy
  remove SWRITE* I/O types
  kill BH_Ordered flag
  vfs: update ctime when changing the file's permission by setfacl
  cramfs: only unlock new inodes
  fix reiserfs_evict_inode end_writeback second call
2010-08-18 09:35:08 -07:00
86ea51d4a2 Merge branch 'merge-devicetree' of git://git.secretlab.ca/git/linux-2.6
* 'merge-devicetree' of git://git.secretlab.ca/git/linux-2.6:
  spi.h: missing kernel-doc notation, please fix
  of: fix missing headers for of_address_to_resource() in MTD and SysACE drivers
  of: Fix missing includes
  ata: update for of_device to platform_device replacement
  microblaze: Fix of: eliminate of_device->node and dev_archdata->{of,prom}_node
  microblaze: Fix of/address: Merge all of the bus translation code
  booting-without-of: Remove nonexistent chapters from TOC, fix numbering
2010-08-18 09:26:17 -07:00
6416ccb789 fs: scale files_lock
fs: scale files_lock

Improve scalability of files_lock by adding per-cpu, per-sb files lists,
protected with an lglock. The lglock provides fast access to the per-cpu lists
to add and remove files. It also provides a snapshot of all the per-cpu lists
(although this is very slow).

One difficulty with this approach is that a file can be removed from the list
by another CPU. We must track which per-cpu list the file is on with a new
variale in the file struct (packed into a hole on 64-bit archs). Scalability
could suffer if files are frequently removed from different cpu's list.

However loads with frequent removal of files imply short interval between
adding and removing the files, and the scheduler attempts to avoid moving
processes too far away. Also, even in the case of cross-CPU removal, the
hardware has much more opportunity to parallelise cacheline transfers with N
cachelines than with 1.

A worst-case test of 1 CPU allocating files subsequently being freed by N CPUs
degenerates to contending on a single lock, which is no worse than before. When
more than one CPU are allocating files, even if they are always freed by
different CPUs, there will be more parallelism than the single-lock case.

Testing results:

On a 2 socket, 8 core opteron, I measure the number of times the lock is taken
to remove the file, the number of times it is removed by the same CPU that
added it, and the number of times it is removed by the same node that added it.

Booting:    locks=  25049 cpu-hits=  23174 (92.5%) node-hits=  23945 (95.6%)
kbuild -j16 locks=2281913 cpu-hits=2208126 (96.8%) node-hits=2252674 (98.7%)
dbench 64   locks=4306582 cpu-hits=4287247 (99.6%) node-hits=4299527 (99.8%)

So a file is removed from the same CPU it was added by over 90% of the time.
It remains within the same node 95% of the time.

Tim Chen ran some numbers for a 64 thread Nehalem system performing a compile.

                throughput
2.6.34-rc2      24.5
+patch          24.9

                us      sys     idle    IO wait (in %)
2.6.34-rc2      51.25   28.25   17.25   3.25
+patch          53.75   18.5    19      8.75

So significantly less CPU time spent in kernel code, higher idle time and
slightly higher throughput.

Single threaded performance difference was within the noise of microbenchmarks.
That is not to say penalty does not exist, the code is larger and more memory
accesses required so it will be slightly slower.

Cc: linux-kernel@vger.kernel.org
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:48 -04:00
2dc91abe03 lglock: introduce special lglock and brlock spin locks
lglock: introduce special lglock and brlock spin locks

This patch introduces "local-global" locks (lglocks). These can be used to:

- Provide fast exclusive access to per-CPU data, with exclusive access to
  another CPU's data allowed but possibly subject to contention, and to provide
  very slow exclusive access to all per-CPU data.
- Or to provide very fast and scalable read serialisation, and to provide
  very slow exclusive serialisation of data (not necessarily per-CPU data).

Brlocks are also implemented as a short-hand notation for the latter use
case.

Thanks to Paul for local/global naming convention.

Cc: linux-kernel@vger.kernel.org
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:48 -04:00
d996b62a8d tty: fix fu_list abuse
tty: fix fu_list abuse

tty code abuses fu_list, which causes a bug in remount,ro handling.

If a tty device node is opened on a filesystem, then the last link to the inode
removed, the filesystem will be allowed to be remounted readonly. This is
because fs_may_remount_ro does not find the 0 link tty inode on the file sb
list (because the tty code incorrectly removed it to use for its own purpose).
This can result in a filesystem with errors after it is marked "clean".

Taking idea from Christoph's initial patch, allocate a tty private struct
at file->private_data and put our required list fields in there, linking
file and tty. This makes tty nodes behave the same way as other device nodes
and avoid meddling with the vfs, and avoids this bug.

The error handling is not trivial in the tty code, so for this bugfix, I take
the simple approach of using __GFP_NOFAIL and don't worry about memory errors.
This is not a problem because our allocator doesn't fail small allocs as a rule
anyway. So proper error handling is left as an exercise for tty hackers.

[ Arguably filesystem's device inode would ideally be divorced from the
driver's pseudo inode when it is opened, but in practice it's not clear whether
that will ever be worth implementing. ]

Cc: linux-kernel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:47 -04:00
ee2ffa0dfd fs: cleanup files_lock locking
fs: cleanup files_lock locking

Lock tty_files with a new spinlock, tty_files_lock; provide helpers to
manipulate the per-sb files list; unexport the files_lock spinlock.

Cc: linux-kernel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:47 -04:00
2a4419b5b2 fs: fs_struct rwlock to spinlock
fs: fs_struct rwlock to spinlock

struct fs_struct.lock is an rwlock with the read-side used to protect root and
pwd members while taking references to them. Taking a reference to a path
typically requires just 2 atomic ops, so the critical section is very small.
Parallel read-side operations would have cacheline contention on the lock, the
dentry, and the vfsmount cachelines, so the rwlock is unlikely to ever give a
real parallelism increase.

Replace it with a spinlock to avoid one or two atomic operations in typical
path lookup fastpath.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:46 -04:00
9cb569d601 remove SWRITE* I/O types
These flags aren't real I/O types, but tell ll_rw_block to always
lock the buffer instead of giving up on a failed trylock.

Instead add a new write_dirty_buffer helper that implements this semantic
and use it from the existing SWRITE* callers.  Note that the ll_rw_block
code had a bug where it didn't promote WRITE_SYNC_PLUG properly, which
this patch fixes.

In the ufs code clean up the helper that used to call ll_rw_block
to mirror sync_dirty_buffer, which is the function it implements for
compound buffers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 01:09:01 -04:00
87e99511ea kill BH_Ordered flag
Instead of abusing a buffer_head flag just add a variant of
sync_dirty_buffer which allows passing the exact type of write
flag required.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 01:09:00 -04:00
5c79a5ae23 spi.h: missing kernel-doc notation, please fix
Added comments in kernel-doc notation for previously added struct fields.

Signed-off-by: Ernst Schwab <eschwab@online.de>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-08-17 22:55:38 -06:00
2a6a432a9c Merge master.kernel.org:/home/rmk/linux-2.6-arm
* master.kernel.org:/home/rmk/linux-2.6-arm:
  VIDEO: amba clcd: don't disable an already disabled clock
  ARM: Tighten check for allowable CPSR values
  ARM: 6329/1: wire up sys_accept4() on ARM
  ARM: 6328/1: Build with -fno-dwarf2-cfi-asm
  ARM: 6326/1: kgdb: fix GDB_MAX_REGS no longer used
2010-08-17 18:11:49 -07:00
d7627467b7 Make do_execve() take a const filename pointer
Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:

arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type

This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to.  This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel().  A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().

do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.

Further kernel_execve() and sys_execve() need to be changed to match.

This has been test built on x86_64, frv, arm and mips.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-17 18:07:43 -07:00
99c796df94 VIDEO: amba clcd: don't disable an already disabled clock
Fix the clock enable/disable tracking in the AMBA CLCD driver so
that the driver doesn't try to disable an already disabled clock,
thereby causing the clock (if shared) to become unbalanced.

This resolves a problem with CLCD on LPC32xx ARM platforms.

Reported-by: Kevin Wells <wellsk40@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-08-17 22:15:09 +01:00