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Author SHA1 Message Date
Linus Torvalds b17b849946 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:
  PM / Runtime: Don't enable interrupts while running in_interrupt
2011-01-28 06:32:49 +10:00
Linus Torvalds 785eb10b9f Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/avr32-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/egtvedt/avr32-2.6:
  avr32: add missing include causing undefined pgtable_page_* references
2011-01-28 06:32:05 +10:00
Shirish Pargaonkar ee2c925850 cifs: More crypto cleanup (try #2)
Replaced md4 hashing function local to cifs module with kernel crypto APIs.
As a result, md4 hashing function and its supporting functions in
file md4.c are not needed anymore.

Cleaned up function declarations, removed forward function declarations,
and removed a header file that is being deleted from being included.

Verified that sec=ntlm/i, sec=ntlmv2/i, and sec=ntlmssp/i work correctly.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
2011-01-27 19:58:13 +00:00
Catalin Marinas 6ae4bd1f0b kmemleak: Allow kmemleak metadata allocations to fail
This patch adds __GFP_NORETRY and __GFP_NOMEMALLOC flags to the kmemleak
metadata allocations so that it has a smaller effect on the users of the
kernel slab allocator. Since kmemleak allocations can now fail more
often, this patch also reduces the verbosity by passing __GFP_NOWARN and
not dumping the stack trace when a kmemleak allocation fails.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Ted Ts'o <tytso@mit.edu>
2011-01-27 18:32:06 +00:00
Jesper Juhl 0a08739e81 kmemleak: remove memset by using kzalloc
We don't need to memset if we just use kzalloc() rather than kmalloc() in
kmemleak_test_init().

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2011-01-27 18:31:51 +00:00
Stefano Stabellini 23febeddbe xen/setup: Route halt operations to safe_halt pvop.
With this patch, the cpuidle driver does not load and
does not issue the mwait operations. Instead the hypervisor
is doing them (b/c we call the safe_halt pvops call).

This fixes quite a lot of bootup issues wherein the user had
to force interrupts for the continuation of the bootup.

Details are discussed in:

http://lists.xensource.com/archives/html/xen-devel/2011-01/msg00535.html

[v2: Wrote the commit description]

Reported-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Tested-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-01-27 12:00:24 -05:00
Stefano Stabellini 7cb31b752c xen/e820: Guard against E820_RAM not having page-aligned size or start.
Under Dell Inspiron 1525, and Intel SandyBridge SDP's the
BIOS e820 RAM is not page-aligned:

[   0.000000]  Xen: 0000000000100000 - 00000000df66d800 (usable)

We were not handling that and ended up setting up a pagetable
that included up to df66e000 with the disastrous effect that when

        memset(NODE_DATA(nodeid), 0, sizeof(pg_data_t));

tried to clear the page it would crash at the 2K mark.

Initially reported by Michael Young @
http://lists.xensource.com/archives/html/xen-devel/2011-01/msg00108.html

The fix is to page-align the size and also take into consideration
the start of the E820 (in case that is not page-aligned either). This
fixes the bootup failure on those affected machines.

This patch is a rework of the Micheal A Young initial patch and
considers the case if the start is not page-aligned.

Reported-by: Michael A Young <m.a.young@durham.ac.uk>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Michael A Young <m.a.young@durham.ac.uk>
2011-01-27 10:49:35 -05:00
Stefan Bader cf04d120d9 xen/p2m: Mark INVALID_P2M_ENTRY the mfn_list past max_pfn.
In case the mfn_list does not have enough entries to fill
a p2m page we do not want the entries from max_pfn up to
the boundary to be filled with unknown values. Hence
set them to INVALID_P2M_ENTRY.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-01-27 10:49:34 -05:00
Colin Cross b48b5f5156 ARM: tegra: clock: Add forward reference to struct clk
Signed-off-by: Colin Cross <ccross@android.com>
2011-01-26 21:28:06 -08:00
Colin Cross cc939754db ARM: tegra: irq: Rename gic pointers to avoid conflicts
A future patch will export gic_mask_irq and gic_unmask_irq.
Rename the pointers in arch/arm/mach-tegra/irq.c to avoid
a compile error.

Signed-off-by: Colin Cross <ccross@android.com>
2011-01-26 21:28:06 -08:00
Grant Likely 867996cb4f arm/tegra: Fix tegra irq_data conversion
Commit 37337a8d5e, "ARM: tegra: irq_data
conversion." missed changing one reference to 'irq' in the function
tegra_gpio_irq_set_type().  This patch fixes the build error.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Lennert Buytenhek <buytenh@secretlab.ca>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Colin Cross <ccross@android.com>
2011-01-26 21:28:06 -08:00
Alex Deucher fa6bee46a6 drm/radeon/kms: fix r6xx+ scanout on BE systems
R6xx+ have per-block swappers.  BE content in the
framebuffer will now be swapped properly during scanout.
Untested, however, the same code is reported working in
the UMS ddx.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>
2011-01-27 13:54:13 +10:00
Alex Deucher d75ee3be44 drm/radeon/kms: clean up some magic numbers
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>
2011-01-27 13:53:30 +10:00
Alex Deucher 9453d62118 drm/radeon/kms: only enable HDMI mode if radeon audio is enabled
Force DVI mode if the user specifies radeon.audio=0.  The driver
doesn't handle HDMI mode properly in some cases.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=27731

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>
2011-01-27 13:52:49 +10:00
Jerome Glisse 6bba2e1168 radeon/kms: fix dp displayport mode validation
Check if there is a big enough dp clock & enough dp lane to
drive the video mode provided.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-By: Alex Deucher <alexdeucher@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Dave Airlie <airlied@gmail.com>
2011-01-27 13:52:05 +10:00
Dave Chinner 7db37c5e65 xfs: fix log ticket leak on forced shutdown.
The kmemleak detector shows this after test 139:

unreferenced object 0xffff880079b88bb0 (size 264):
  comm "xfs_io", pid 4904, jiffies 4294909382 (age 276.824s)
  hex dump (first 32 bytes):
    00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00  .....N..........
    ff ff ff ff ff ff ff ff 48 7b c9 82 ff ff ff ff  ........H{......
  backtrace:
    [<ffffffff81afb04d>] kmemleak_alloc+0x2d/0x60
    [<ffffffff8115c6cf>] kmem_cache_alloc+0x13f/0x2b0
    [<ffffffff814aaa97>] kmem_zone_alloc+0x77/0xf0
    [<ffffffff814aab2e>] kmem_zone_zalloc+0x1e/0x50
    [<ffffffff8148f394>] xlog_ticket_alloc+0x34/0x170
    [<ffffffff81494444>] xlog_cil_push+0xa4/0x3f0
    [<ffffffff81494eca>] xlog_cil_force_lsn+0x15a/0x160
    [<ffffffff814933a5>] _xfs_log_force_lsn+0x75/0x2d0
    [<ffffffff814a264d>] _xfs_trans_commit+0x2bd/0x2f0
    [<ffffffff8148bfdd>] xfs_iomap_write_allocate+0x1ad/0x350
    [<ffffffff814ac17f>] xfs_map_blocks+0x21f/0x370
    [<ffffffff814ad1b7>] xfs_vm_writepage+0x1c7/0x550
    [<ffffffff8112200a>] __writepage+0x1a/0x50
    [<ffffffff81122df2>] write_cache_pages+0x1c2/0x4c0
    [<ffffffff81123117>] generic_writepages+0x27/0x30
    [<ffffffff814aba5d>] xfs_vm_writepages+0x5d/0x80

By inspection, the leak occurs when xlog_write() returns and error
and we jump to the abort path without dropping the reference on the
active ticket.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
2011-01-27 12:02:00 +11:00
Michael Chan 4bb9ebc780 bnx2: Eliminate AER error messages on systems not supporting it
On PPC for example, AER is not supported and we see unnecessary AER
error message without this patch:

bnx2 0003:01:00.1: pci_cleanup_aer_uncorrect_error_status failed 0xfffffffb

Reported-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-26 14:28:52 -08:00
Michael Chan 5138826b52 cnic: Fix big endian bug
The chip's page tables did not set up properly on big endian machines,
causing EEH errors on PPC machines.

Reported-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-26 14:26:00 -08:00
David S. Miller 7cc2edb834 xfrm6: Don't forget to propagate peer into ipsec route.
Like ipv4, we have to propagate the ipv6 route peer into
the ipsec top-level route during instantiation.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-26 13:41:03 -08:00
Matt Carlson 34c92049ac tg3: Use new VLAN code
This patch pivots the tg3 driver to the new VLAN infrastructure.
All references to vlgrp have been removed.  The driver still attempts to
disable VLAN tag stripping if CONFIG_VLAN_8021Q or
CONFIG_VLAN_8021Q_MODULE is not defined.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-26 13:13:10 -08:00
David S. Miller 9b6941d8b1 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-2.6 2011-01-26 11:49:49 -08:00
David Henningsson ded9f5238b ALSA: HDA: Fix automute on Thinkpad L412/L512
BugLink: http://bugs.launchpad.net/bugs/707902

More Thinkpad machines with invalid SKU found, that disables
automute between speakers and headphones on these machines.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2011-01-26 14:37:53 +01:00
Hans-Christian Egtvedt 6cb8e872c8 avr32: add missing include causing undefined pgtable_page_* references
This patch adds the linux/mm.h header file to the AVR32 arch pgalloc.c
implementation to fix the undefined reference to pgtable_page_ctor() and
pgtable_page_dtor().

Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
2011-01-26 12:35:15 +01:00
Paul Turner 05ca62c6ca sched: Use rq->clock_task instead of rq->clock for correctly maintaining load averages
The delta in clock_task is a more fair attribution of how much time a tg has
been contributing load to the current cpu.

While not really important it also means we're more in sync (by magnitude)
with respect to periodic updates (since __update_curr deltas are clock_task
based).

Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044852.007092349@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 12:31:03 +01:00
Paul Turner b815f1963e sched: Fix/remove redundant cfs_rq checks
Since updates are against an entity's queuing cfs_rq it's not possible to
enter update_cfs_{shares,load} with a NULL cfs_rq.  (Indeed, update_cfs_load
would crash prior to the check if we did anyway since we load is examined
during the initializers).

Also, in the update_cfs_load case there's no point
in maintaining averages for rq->cfs_rq since we don't perform shares
distribution at that level -- NULL check is replaced accordingly.

Thanks to Dan Carpenter for pointing out the deference before NULL check.

Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044851.825284940@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 12:31:02 +01:00
Paul Turner e37b6a7b27 sched: Fix sign under-flows in wake_affine
While care is taken around the zero-point in effective_load to not exceed
the instantaneous rq->weight, it's still possible (e.g. using wake_idx != 0)
for (load + effective_load) to underflow.

In this case the comparing the unsigned values can result in incorrect balanced
decisions.

Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044851.734245014@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 12:31:01 +01:00
Dave Airlie 52bb4a7391 Merge branch 'drm-nouveau-next' of git://git.freedesktop.org/git/nouveau/linux-2.6 into drm-fixes
* 'drm-nouveau-next' of git://git.freedesktop.org/git/nouveau/linux-2.6:
  drm/nvc0/grctx: correct an off-by-one
  drm/nv50: Fix race with PFIFO during PGRAPH context destruction.
  drm/nouveau: Workaround incorrect DCB entry on a GeForce3 Ti 200.
  drm/nvc0: implement irq handler for whatever's at 0x14xxxx
  drm/nvc0: fix incorrect TPC register setup
  drm/nouveau: probe for adt7473 before f75375
  drm/nouveau: remove dead function definition
2011-01-26 17:12:42 +10:00
Eric Dumazet 889a7a6a5d percpu, x86: Fix percpu_xchg_op()
These recent percpu commits:

  2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section
  8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics

Caused this 'perf top' crash:

 Kernel panic - not syncing: Fatal exception in interrupt
 Pid: 0, comm: swapper Tainted: G     D
 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>]
    ? panic
    ? kmsg_dump
    ? kmsg_dump
    ? oops_end
    ? no_context
    ? __bad_area_nosemaphore
    ? perf_output_begin
    ? bad_area_nosemaphore
    ? do_page_fault
    ? __task_pid_nr_ns
    ? perf_event_tid
    ? __perf_event_header__init_id
    ? validate_chain
    ? perf_output_sample
    ? trace_hardirqs_off
    ? page_fault
    ? irq_work_run
    ? update_process_times
    ? tick_sched_timer
    ? tick_sched_timer
    ? __run_hrtimer
    ? hrtimer_interrupt
    ? account_system_vtime
    ? smp_apic_timer_interrupt
    ? apic_timer_interrupt
 ...

Looking at assembly code, I found:

list = this_cpu_xchg(irq_work_list, NULL);

gives this wrong code : (gcc-4.1.2 cross compiler)

ffffffff810bc45e:
	mov    %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne    ffffffff810bc45e <irq_work_run+0x3e>
	test   %rax,%rax
	je     ffffffff810bc4aa <irq_work_run+0x8a>

Tell gcc we dirty eax/rax register in percpu_xchg_op()

Compiler must use another register to store pxo_new__

We also dont need to reload percpu value after a jump,
since a 'failed' cmpxchg already updated eax/rax

Wrong generated code was :
	xor     %rax,%rax   /* load 0 into %rax */
1:	mov     %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne     1b
	test    %rax,%rax

After patch :

	xor     %rdx,%rdx   /* load 0 into %rdx */
	mov     %gs:0xead0,%rax
1:	cmpxchg %rdx,%gs:0xead0
	jne     1b:
	test    %rax,%rax

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 08:10:49 +01:00
Yinghai Lu 9a57c3e487 x86: Remove left over system_64.h
Left-over from the x86 merge ...

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4D3E23D1.7010405@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26 08:05:58 +01:00
Linus Torvalds 6fb1b30425 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: wacom - pass touch resolution to clients through input_absinfo
  Input: wacom - add 2 Bamboo Pen and touch models
  Input: sysrq - ensure sysrq_enabled and __sysrq_enabled are consistent
  Input: sparse-keymap - fix KEY_VSW handling in sparse_keymap_setup
  Input: tegra-kbc - add tegra keyboard driver
  Input: gpio_keys - switch to using request_any_context_irq
  Input: serio - allow registered drivers to get status flag
  Input: ct82710c - return proper error code for ct82c710_open
  Input: bu21013_ts - added regulator support
  Input: bu21013_ts - remove duplicate resolution parameters
  Input: tnetv107x-ts - don't treat NULL clk as an error
  Input: tnetv107x-keypad - don't treat NULL clk as an error

Fix up trivial conflicts in drivers/input/keyboard/Makefile due to
additions of tc3589x/Tegra drivers
2011-01-26 16:31:44 +10:00
Sonic Zhang a34650f0f1 mmc: bfin_sdh: fix alloc size for private data
The bfin_sdh driver allocates the wrong size for the private data
in the mmc_host.  The first parameter of mmc_alloc_host should be
the size of the local driver struct rather than the common mmc_host.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: <stable@kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
2011-01-26 00:28:41 -05:00
Jaehoon Chung 548f07d2a3 mmc: sdhci-s3c: add platform_8bit_width() hook
We have 8-bit width support but is not a v3 controller.
So we need platform_8bit_width() to support 8-bit buswidth.
Also we need MMC_CAP_8_BIT_DATA, so we add it in platdata.

This gets 8-bit support working again on s3c, after we previously
disabled 8-bit by default on non-v3 controllers.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2011-01-26 00:27:57 -05:00
Andy Adamson c7a360b05b NFS construct consistent co_ownerid for v4.1
As stated in section 2.4 of RFC 5661, subsequent instances of the client need
to present the same co_ownerid. Concatinate the client's IP dot address,
host name, and the rpc_auth pseudoflavor to form the co_ownerid.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-25 22:49:14 -05:00
Jamie Iles 3119cbda85 mmc: jz4740: don't treat NULL clk as an error
clk_get() returns a struct clk cookie to the driver and some platforms
may return NULL if they only support a single clock.  clk_get() has only
failed if it returns a ERR_PTR() encoded pointer.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2011-01-25 21:53:51 -05:00
Russell King - ARM Linux 9047b435a0 mmc: mmci: don't read command response when invalid
Don't read the command response from the registers when either the
command timed out (because there was no response from the card) or
the checksum on the response was invalid.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Chris Ball <cjb@laptop.org>
2011-01-25 21:53:46 -05:00
Jesper Juhl 021cb59ae3 mmc: ushc: Remove duplicate include of usb.h
Including usb.h once is enough in drivers/mmc/host/ushc.c
This removes the duplicate.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Chris Ball <cjb@laptop.org>
2011-01-25 21:53:43 -05:00
Ping Cheng 409550f290 Input: wacom - pass touch resolution to clients through input_absinfo
Also remove fake ABS_RX/ABS_RY "axes" that were used to report physical
dimensions now that we have better way.

Signed-off-by: Ping Cheng <pingc@wacom.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2011-01-25 18:04:05 -08:00
Torben Hohn ac751efa6a console: rename acquire/release_console_sem() to console_lock/unlock()
The -rt patches change the console_semaphore to console_mutex.  As a
result, a quite large chunk of the patches changes all
acquire/release_console_sem() to acquire/release_console_mutex()

This commit makes things use more neutral function names which dont make
implications about the underlying lock.

The only real change is the return value of console_trylock which is
inverted from try_acquire_console_sem()

This patch also paves the way to switching console_sem from a semaphore to
a mutex.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: make console_trylock return 1 on success, per Geert]
Signed-off-by: Torben Hohn <torbenh@gmx.de>
Cc: Thomas Gleixner <tglx@tglx.de>
Cc: Greg KH <gregkh@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:06 +10:00
Phillip Lougher 3689456b4b squashfs: fix use of uninitialised variable in zlib & xz decompressors
Fix potential use of uninitialised variable caused by recent
decompressor code optimisations.

In zlib_uncompress (zlib_wrapper.c) we have

	int zlib_err, zlib_init = 0;
	...
	do {
		...
			if (avail == 0) {
				offset = 0;
				put_bh(bh[k++]);
				continue;
			}
		...
		zlib_err = zlib_inflate(stream, Z_SYNC_FLUSH);
		...
	} while (zlib_err == Z_OK);

If continue is executed (avail == 0) then the while condition will be
evaluated testing zlib_err, which is uninitialised first time around the
loop.

Fix this by getting rid of the 'if (avail == 0)' condition test, this
edge condition should not be being handled in the decompressor code, and
instead handle it generically in the caller code.

Similarly for xz_wrapper.c.

Incidentally, on most architectures (bar Mips and Parisc), no
uninitialised variable warning is generated by gcc, this is because the
while condition test on continue is optimised out and not performed
(when executing continue zlib_err has not been changed since entering
the loop, and logically if the while condition was true previously, then
it's still true).

Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Reported-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:05 +10:00
Toshiyuki Okajima ac15ee691f radix_tree: radix_tree_gang_lookup_tag_slot() may never return
Executed command: fsstress -d /mnt -n 600 -p 850

  crash> bt
  PID: 7947   TASK: ffff880160546a70  CPU: 0   COMMAND: "fsstress"
   #0 [ffff8800dfc07d00] machine_kexec at ffffffff81030db9
   #1 [ffff8800dfc07d70] crash_kexec at ffffffff810a7952
   #2 [ffff8800dfc07e40] oops_end at ffffffff814aa7c8
   #3 [ffff8800dfc07e70] die_nmi at ffffffff814aa969
   #4 [ffff8800dfc07ea0] do_nmi_callback at ffffffff8102b07b
   #5 [ffff8800dfc07f10] do_nmi at ffffffff814aa514
   #6 [ffff8800dfc07f50] nmi at ffffffff814a9d60
      [exception RIP: __lookup_tag+100]
      RIP: ffffffff812274b4  RSP: ffff88016056b998  RFLAGS: 00000287
      RAX: 0000000000000000  RBX: 0000000000000002  RCX: 0000000000000006
      RDX: 000000000000001d  RSI: ffff88016056bb18  RDI: ffff8800c85366e0
      RBP: ffff88016056b9c8   R8: ffff88016056b9e8   R9: 0000000000000000
      R10: 000000000000000e  R11: ffff8800c8536908  R12: 0000000000000010
      R13: 0000000000000040  R14: ffffffffffffffc0  R15: ffff8800c85366e0
      ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
  <NMI exception stack>
   #7 [ffff88016056b998] __lookup_tag at ffffffff812274b4
   #8 [ffff88016056b9d0] radix_tree_gang_lookup_tag_slot at ffffffff81227605
   #9 [ffff88016056ba20] find_get_pages_tag at ffffffff810fc110
  #10 [ffff88016056ba80] pagevec_lookup_tag at ffffffff81105e85
  #11 [ffff88016056baa0] write_cache_pages at ffffffff81104c47
  #12 [ffff88016056bbd0] generic_writepages at ffffffff81105014
  #13 [ffff88016056bbe0] do_writepages at ffffffff81105055
  #14 [ffff88016056bbf0] __filemap_fdatawrite_range at ffffffff810fb2cb
  #15 [ffff88016056bc40] filemap_write_and_wait_range at ffffffff810fb32a
  #16 [ffff88016056bc70] generic_file_direct_write at ffffffff810fb3dc
  #17 [ffff88016056bce0] __generic_file_aio_write at ffffffff810fcee5
  #18 [ffff88016056bda0] generic_file_aio_write at ffffffff810fd085
  #19 [ffff88016056bdf0] do_sync_write at ffffffff8114f9ea
  #20 [ffff88016056bf00] vfs_write at ffffffff8114fcf8
  #21 [ffff88016056bf30] sys_write at ffffffff81150691
  #22 [ffff88016056bf80] system_call_fastpath at ffffffff8100c0b2

I think this root cause is the following:

 radix_tree_range_tag_if_tagged() always tags the root tag with settag
 if the root tag is set with iftag even if there are no iftag tags
 in the specified range (Of course, there are some iftag tags
 outside the specified range).

===============================================================================
[[[Detailed description]]]

(1) Why cannot radix_tree_gang_lookup_tag_slot() return forever?

__lookup_tag():
 - Return with 0.
 - Return with the index which is not bigger than the old one as the
   input parameter.

Therefore the following "while" repeats forever because the above
conditions cause "ret" not to be updated and the cur_index cannot be
changed into the bigger one.

(So, radix_tree_gang_lookup_tag_slot() cannot return forever.)

radix_tree_gang_lookup_tag_slot():
1178         while (ret < max_items) {
1179                 unsigned int slots_found;
1180                 unsigned long next_index;       /* Index of next search */
1181
1182                 if (cur_index > max_index)
1183                         break;
1184                 slots_found = __lookup_tag(node, results + ret,
1185                                 cur_index, max_items - ret, &next_index,
tag);
1186                 ret += slots_found;
			// cannot update ret because slots_found == 0.
			// so, this while loops forever.
1187                 if (next_index == 0)
1188                         break;
1189                 cur_index = next_index;
1190         }

(2) Why does __lookup_tag() return with 0 and doesn't update the index?

Assuming the following:
  - the one of the slot in radix_tree_node is NULL.
  - the one of the tag which corresponds to the slot sets with
    PAGECACHE_TAG_TOWRITE or other.
  - In a certain height(!=0), the corresponding index is 0.

a) __lookup_tag() notices that the tag is set.

1005 static unsigned int
1006 __lookup_tag(struct radix_tree_node *slot, void ***results, unsigned long index,
1007         unsigned int max_items, unsigned long *next_index, unsigned int tag)
1008 {
1009         unsigned int nr_found = 0;
1010         unsigned int shift, height;
1011
1012         height = slot->height;
1013         if (height == 0)
1014                 goto out;
1015         shift = (height-1) * RADIX_TREE_MAP_SHIFT;
1016
1017         while (height > 0) {
1018                 unsigned long i = (index >> shift) & RADIX_TREE_MAP_MASK ;
1019
1020                 for (;;) {
1021                         if (tag_get(slot, tag, i))
1022                                 break;
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
* the index is not updated yet.

b) __lookup_tag() notices that the slot is NULL.

1023                         index &= ~((1UL << shift) - 1);
1024                         index += 1UL << shift;
1025                         if (index == 0)
1026                                 goto out;       /* 32-bit wraparound */
1027                         i++;
1028                         if (i == RADIX_TREE_MAP_SIZE)
1029                                 goto out;
1030                 }
1031                 height--;
1032                 if (height == 0) {      /* Bottom level: grab some items */
...
1055                 }
1056                 shift -= RADIX_TREE_MAP_SHIFT;
1057                 slot = rcu_dereference_raw(slot->slots[i]);
1058                 if (slot == NULL)
1059                         break;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

c) __lookup_tag() doesn't update the index and return with 0.

1060         }
1061 out:
1062         *next_index = index;
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
1063         return nr_found;
1064 }

(3) Why is the slot NULL even if the tag is set?

Because radix_tree_range_tag_if_tagged() always sets the root tag with
PAGECACHE_TAG_TOWRITE if the root tag is set with PAGECACHE_TAG_DIRTY,
even if there is no tag which can be set with PAGECACHE_TAG_TOWRITE
in the specified range (from *first_indexp to last_index). Of course,
some PAGECACHE_TAG_DIRTY nodes must exist outside the specified range.
(radix_tree_range_tag_if_tagged() is called only from tag_pages_for_writeback())

 640 unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root
*root,
 641                 unsigned long *first_indexp, unsigned long last_index,
 642                 unsigned long nr_to_tag,
 643                 unsigned int iftag, unsigned int settag)
 644 {
 645         unsigned int height = root->height;
 646         struct radix_tree_path path[height];
 647         struct radix_tree_path *pathp = path;
 648         struct radix_tree_node *slot;
 649         unsigned int shift;
 650         unsigned long tagged = 0;
 651         unsigned long index = *first_indexp;
 652
 653         last_index = min(last_index, radix_tree_maxindex(height));
 654         if (index > last_index)
 655                 return 0;
 656         if (!nr_to_tag)
 657                 return 0;
 658         if (!root_tag_get(root, iftag)) {
 659                 *first_indexp = last_index + 1;
 660                 return 0;
 661         }
 662         if (height == 0) {
 663                 *first_indexp = last_index + 1;
 664                 root_tag_set(root, settag);
 665                 return 1;
 666         }
...
 733         root_tag_set(root, settag);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 734         *first_indexp = index;
 735
 736         return tagged;
 737 }

As the result, there is no radix_tree_node which is set with
PAGECACHE_TAG_TOWRITE but the root tag(radix_tree_root) is set with
PAGECACHE_TAG_TOWRITE.

[figure: inside radix_tree]
(Please see the figure with typewriter font)
===========================================
          [roottag = DIRTY]
                 |             tag=0:NOTHING
         tag[0 0 0 1]              1:DIRTY
            [x x x +]              2:WRITEBACK
                   |               3:DIRTY,WRITEBACK
                   p               4:TOWRITE
             <--->                 5:DIRTY,TOWRITE ...
     specified range (index: 0 to 2)

* There is no DIRTY tag within the specified range.
 (But there is a DIRTY tag outside that range.)

            | | | | | | | | |
    after calling tag_pages_for_writeback()
            | | | | | | | | |
            v v v v v v v v v

          [roottag = DIRTY,TOWRITE]
                 |                 p is "page".
         tag[0 0 0 1]              x is NULL.
            [x x x +]              +- is a pointer to "page".
                   |
                   p

* But TOWRITE tag is set on the root tag.
============================================

After that, radix_tree_extend() via radix_tree_insert() is called
when the page is added.
This function sets the new radix_tree_node with PAGECACHE_TAG_TOWRITE
to succeed the status of the root tag.

 246 static int radix_tree_extend(struct radix_tree_root *root, unsigned long
index)
 247 {
 248         struct radix_tree_node *node;
 249         unsigned int height;
 250         int tag;
 251
 252         /* Figure out what the height should be.  */
 253         height = root->height + 1;
 254         while (index > radix_tree_maxindex(height))
 255                 height++;
 256
 257         if (root->rnode == NULL) {
 258                 root->height = height;
 259                 goto out;
 260         }
 261
 262         do {
 263                 unsigned int newheight;
 264                 if (!(node = radix_tree_node_alloc(root)))
 265                         return -ENOMEM;
 266
 267                 /* Increase the height.  */
 268                 node->slots[0] = radix_tree_indirect_to_ptr(root->rnode);
 269
 270                 /* Propagate the aggregated tag info into the new root */
 271                 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
 272                         if (root_tag_get(root, tag))
 273                                 tag_set(node, tag, 0);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 274                 }

===========================================
          [roottag = DIRTY,TOWRITE]
                 |     :
         tag[0 0 0 1] [0 0 0 0]
            [x x x +] [+ x x x]
                   |   |
                   p   p (new page)

            | | | | | | | | |
    after calling radix_tree_insert
            | | | | | | | | |
            v v v v v v v v v

          [roottag = DIRTY,TOWRITE]
                 |
         tag [5 0 0 0]    *  DIRTY and TOWRITE tags are
             [+ + x x]       succeeded to the new node.
              | |
  tag [0 0 0 1] [0 0 0 0]
      [x x x +] [+ x x x]
             |   |
             p   p
============================================

After that, the index 3 page is released by remove_from_page_cache().
Then we can make the situation that the tag is set with PAGECACHE_TAG_TOWRITE
and that the slot which corresponds to the tag is NULL.
===========================================
          [roottag = DIRTY,TOWRITE]
                 |
         tag [5 0 0 0]
             [+ + x x]
              | |
  tag [0 0 0 1] [0 0 0 0]
      [x x x +] [+ x x x]
             |   |
             p   p
         (remove)

            | | | | | | | | |
    after calling remove_page_cache
            | | | | | | | | |
            v v v v v v v v v

          [roottag = DIRTY,TOWRITE]
                 |
         tag [4 0 0 0]      * Only DIRTY tag is cleared
             [x + x x]        because no TOWRITE tag is existed
                |             in the bottom node.
                [0 0 0 0]
                [+ x x x]
                 |
                 p
============================================

To solve this problem

Change to that radix_tree_tag_if_tagged() doesn't tag the root tag
if it doesn't set any tags within the specified range.

Like this.
============================================
 640 unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root
*root,
 641                 unsigned long *first_indexp, unsigned long last_index,
 642                 unsigned long nr_to_tag,
 643                 unsigned int iftag, unsigned int settag)
 644 {
 650         unsigned long tagged = 0;
...
 733 	     if (tagged)
^^^^^^^^^^^^^^^^^^^^^^^^
 734            root_tag_set(root, settag);
 735         *first_indexp = index;
 736
 737         return tagged;
 738 }

============================================

Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:04 +10:00
Voss, Nikolaus 1817dc0370 drivers/clocksource/tcb_clksrc.c: fix init sequence
setup_irq() was called before clockevents_register_device() which is
needed by the irq handler.  Bug was reproducible by restarting the
kernel using kexec (reliable crash).

Signed-off-by: Nikolaus Voss <n.voss@weinmann.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:04 +10:00
KAMEZAWA Hiroyuki 52dbb90509 memcg: fix race at move_parent around compound_order()
A fix up mem_cgroup_move_parent() which use compound_order() in
asynchronous manner.  This compound_order() may return unknown value
because we don't take lock.  Use PageTransHuge() and HPAGE_SIZE instead
of it.

Also clean up for mem_cgroup_move_parent().
 - remove unnecessary initialization of local variable.
 - rename charge_size -> page_size
 - remove unnecessary (wrong) comment.
 - added a comment about THP.

Note:
 Current design take compound_page_lock() in caller of move_account().
 This should be revisited when we implement direct move_task of hugepage
 without splitting.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-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>
2011-01-26 10:50:04 +10:00
KAMEZAWA Hiroyuki 3d37c4a919 memcg: bugfix check mem_cgroup_disabled() at split fixup
mem_cgroup_disabled() should be checked at splitting.  If disabled, no
heavy work is necesary.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
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>
2011-01-26 10:50:03 +10:00
KAMEZAWA Hiroyuki 01c88e2d6b memcg: fix account leak at failure of memsw acconting
Commit 4b53433468 ("memcg: clean up try_charge main loop") removes a
cancel of charge at case: memory charge-> success.  mem+swap charge->
failure.

This leaks usage of memory.  Fix it.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: <stable@kernel.org>	[2.6.36+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:03 +10:00
Minchan Kim 28bd65781c mm: migration: clarify migrate_pages() comment
Callers of migrate_pages should putback_lru_pages to return pages
isolated to LRU or free list.  Now comment is rather confusing.  It says
caller always have to call it.

It is more clear to point out that the caller has to call it if
migrate_pages's return value isn't zero.

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:02 +10:00
Andrea Arcangeli 33a938774f mm: compaction: don't depend on HUGETLB_PAGE
Commit 5d6892407 ("thp: select CONFIG_COMPACTION if TRANSPARENT_HUGEPAGE
enabled") causes this warning during the configuration process:

  warning: (TRANSPARENT_HUGEPAGE) selects COMPACTION which has unmet
  direct dependencies (EXPERIMENTAL && HUGETLB_PAGE && MMU)

COMPACTION doesn't depend on HUGETLB_PAGE, it doesn't depend on THP
either, it is also useful for regular alloc_pages(order > 0) including
the very kernel stack during fork (THREAD_ORDER = 1).  It's always
better to enable COMPACTION.

The warning should be an error because we would end up with MIGRATION
not selected, and COMPACTION wouldn't work without migration (despite it
seems to build with an inline migrate_pages returning -ENOSYS).

I'd also like to remove EXPERIMENTAL: compaction has been in the kernel
for some releases (for full safety the default remains disabled which I
think is enough).

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Luca Tettamanti <kronos.it@gmail.com>
Tested-by: Luca Tettamanti <kronos.it@gmail.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:02 +10:00
Jesper Juhl 8dba474f03 mm/memcontrol.c: fix uninitialized variable use in mem_cgroup_move_parent()
In mm/memcontrol.c::mem_cgroup_move_parent() there's a path that jumps
to the 'put_back' label

  	ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, charge);
  	if (ret || !parent)
  		goto put_back;

where we'll

  	if (charge > PAGE_SIZE)
  		compound_unlock_irqrestore(page, flags);

but, we have not assigned anything to 'flags' at this point, nor have we
called 'compound_lock_irqsave()' (which is what sets 'flags').  The
'put_back' label should be moved below the call to
compound_unlock_irqrestore() as per this patch.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:01 +10:00
David Rientjes 2ff754fa8f mm: clear pages_scanned only if draining a pcp adds pages to the buddy allocator
Commit 0e093d9976 ("writeback: do not sleep on the congestion queue if
there are no congested BDIs or if significant congestion is not being
encountered in the current zone") uncovered a livelock in the page
allocator that resulted in tasks infinitely looping trying to find
memory and kswapd running at 100% cpu.

The issue occurs because drain_all_pages() is called immediately
following direct reclaim when no memory is freed and try_to_free_pages()
returns non-zero because all zones in the zonelist do not have their
all_unreclaimable flag set.

When draining the per-cpu pagesets back to the buddy allocator for each
zone, the zone->pages_scanned counter is cleared to avoid erroneously
setting zone->all_unreclaimable later.  The problem is that no pages may
actually be drained and, thus, the unreclaimable logic never fails
direct reclaim so the oom killer may be invoked.

This apparently only manifested after wait_iff_congested() was
introduced and the zone was full of anonymous memory that would not
congest the backing store.  The page allocator would infinitely loop if
there were no other tasks waiting to be scheduled and clear
zone->pages_scanned because of drain_all_pages() as the result of this
change before kswapd could scan enough pages to trigger the reclaim
logic.  Additionally, with every loop of the page allocator and in the
reclaim path, kswapd would be kicked and would end up running at 100%
cpu.  In this scenario, current and kswapd are all running continuously
with kswapd incrementing zone->pages_scanned and current clearing it.

The problem is even more pronounced when current swaps some of its
memory to swap cache and the reclaimable logic then considers all active
anonymous memory in the all_unreclaimable logic, which requires a much
higher zone->pages_scanned value for try_to_free_pages() to return zero
that is never attainable in this scenario.

Before wait_iff_congested(), the page allocator would incur an
unconditional timeout and allow kswapd to elevate zone->pages_scanned to
a level that the oom killer would be called the next time it loops.

The fix is to only attempt to drain pcp pages if there is actually a
quantity to be drained.  The unconditional clearing of
zone->pages_scanned in free_pcppages_bulk() need not be changed since
other callers already ensure that draining will occur.  This patch
ensures that free_pcppages_bulk() will actually free memory before
calling into it from drain_all_pages() so zone->pages_scanned is only
cleared if appropriate.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:01 +10:00
David Rientjes f33261d75b mm: fix deferred congestion timeout if preferred zone is not allowed
Before 0e093d9976 ("writeback: do not sleep on the congestion queue if
there are no congested BDIs or if significant congestion is not being
encountered in the current zone"), preferred_zone was only used for NUMA
statistics, to determine the zoneidx from which to allocate from given
the type requested, and whether to utilize memory compaction.

wait_iff_congested(), though, uses preferred_zone to determine if the
congestion wait should be deferred because its dirty pages are backed by
a congested bdi.  This incorrectly defers the timeout and busy loops in
the page allocator with various cond_resched() calls if preferred_zone
is not allowed in the current context, usually consuming 100% of a cpu.

This patch ensures preferred_zone is an allowed zone in the fastpath
depending on whether current is constrained by its cpuset or nodes in
its mempolicy (when the nodemask passed is non-NULL).  This is correct
since the fastpath allocation always passes ALLOC_CPUSET when trying to
allocate memory.  In the slowpath, this patch resets preferred_zone to
the first zone of the allowed type when the allocation is not
constrained by current's cpuset, i.e.  it does not pass ALLOC_CPUSET.

This patch also ensures preferred_zone is from the set of allowed nodes
when called from within direct reclaim since allocations are always
constrained by cpusets in this context (it is blockable).

Both of these uses of cpuset_current_mems_allowed are protected by
get_mems_allowed().

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:00 +10:00
Alexander Gordeev 4f542e3dd9 pps: claim parallel port exclusively
Both pps_parport and pps_gen_parport are written in a way that they
can't share a port with any other driver.  This can result in locking up
the process that loads modules or even the whole kernel if the modules
are compiled in.  Use PARPORT_FLAG_EXCL to indicate this.

Signed-off-by: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Cc: Alexander Gordeev <lasaine@lvk.cs.msu.su>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26 10:50:00 +10:00