Linus Torvalds [Mon, 20 Jun 2011 15:58:07 +0000 (08:58 -0700)]
Merge branch 'kvm-updates/3.0' of git://git.kernel.org/pub/scm/virt/kvm/kvm
* 'kvm-updates/3.0' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: Fix register corruption in pvclock_scale_delta
KVM: MMU: fix opposite condition in mapping_level_dirty_bitmap
KVM: VMX: do not overwrite uptodate vcpu->arch.cr3 on KVM_SET_SREGS
KVM: MMU: Fix build warnings in walk_addr_generic()
Zachary Amsden [Thu, 16 Jun 2011 03:50:04 +0000 (20:50 -0700)]
KVM: Fix register corruption in pvclock_scale_delta
The 128-bit multiply in pvclock.h was missing an output constraint for
EDX which caused a register corruption to appear. Thanks to Ulrich for
diagnosing the EDX corruption and Avi for providing this fix.
Signed-off-by: Zachary Amsden <zamsden@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Borislav Petkov [Mon, 30 May 2011 20:11:17 +0000 (22:11 +0200)]
KVM: MMU: Fix build warnings in walk_addr_generic()
On 3.0-rc1 I get
In file included from arch/x86/kvm/mmu.c:2856:
arch/x86/kvm/paging_tmpl.h: In function ‘paging32_walk_addr_generic’:
arch/x86/kvm/paging_tmpl.h:124: warning: ‘ptep_user’ may be used uninitialized in this function
In file included from arch/x86/kvm/mmu.c:2852:
arch/x86/kvm/paging_tmpl.h: In function ‘paging64_walk_addr_generic’:
arch/x86/kvm/paging_tmpl.h:124: warning: ‘ptep_user’ may be used uninitialized in this function
Linus Torvalds [Sun, 19 Jun 2011 16:00:18 +0000 (09:00 -0700)]
Merge branches 'perf-urgent-for-linus', 'sched-urgent-for-linus', 'timers-urgent-for-linus' and 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
tools/perf: Fix static build of perf tool
tracing: Fix regression in printk_formats file
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
generic-ipi: Fix kexec boot crash by initializing call_single_queue before enabling interrupts
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
clocksource: Make watchdog robust vs. interruption
timerfd: Fix wakeup of processes when timer is cancelled on clock change
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, MAINTAINERS: Add x86 MCE people
x86, efi: Do not reserve boot services regions within reserved areas
Linus Torvalds [Sun, 19 Jun 2011 15:56:56 +0000 (08:56 -0700)]
Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
rcu: Move RCU_BOOST #ifdefs to header file
rcu: use softirq instead of kthreads except when RCU_BOOST=y
rcu: Use softirq to address performance regression
rcu: Simplify curing of load woes
x86, efi: Do not reserve boot services regions within reserved areas
Commit 916f676f8dc started reserving boot service code since some systems
require you to keep that code around until SetVirtualAddressMap is called.
However, in some cases those areas will overlap with reserved regions.
The proper medium-term fix is to fix the bootloader to prevent the
conflicts from occurring by moving the kernel to a better position,
but the kernel should check for this possibility, and only reserve regions
which can be reserved.
Signed-off-by: Maarten Lankhorst <m.b.lankhorst@gmail.com> Link: http://lkml.kernel.org/r/4DF7A005.1050407@gmail.com Acked-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Guenter Roeck [Tue, 24 May 2011 19:34:55 +0000 (12:34 -0700)]
hwmon: (s3c) Initialize sysfs attributes
Initialize dynamically allocated sysfs attributes before device_create_file()
call to suppress lockdep_init_map() warning if lockdep debugging is enabled.
Guenter Roeck [Tue, 24 May 2011 19:34:12 +0000 (12:34 -0700)]
hwmon: (ibmpex) Initialize sysfs attributes
Initialize dynamically allocated sysfs attributes before device_create_file()
call to suppress lockdep_init_map() warning if lockdep debugging is enabled.
Guenter Roeck [Tue, 24 May 2011 19:33:26 +0000 (12:33 -0700)]
hwmon: (ibmaem) Initialize sysfs attributes
Initialize dynamically allocated sysfs attributes before device_create_file()
call to suppress lockdep_init_map() warning if lockdep debugging is enabled.
Linus Torvalds [Sat, 18 Jun 2011 04:13:43 +0000 (21:13 -0700)]
Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
[CPUFREQ] powernow-k8: Don't try to transition if the pstate is incorrect
[CPUFREQ] powernow-k8: Don't notify of successful transition if we failed (vid case).
[CPUFREQ] Don't set stat->last_index to -1 if the pol->cur has incorrect value.
Linus Torvalds [Sat, 18 Jun 2011 02:05:36 +0000 (19:05 -0700)]
mm: avoid anon_vma_chain allocation under anon_vma lock
Hugh Dickins points out that lockdep (correctly) spots a potential
deadlock on the anon_vma lock, because we now do a GFP_KERNEL allocation
of anon_vma_chain while doing anon_vma_clone(). The problem is that
page reclaim will want to take the anon_vma lock of any anonymous pages
that it will try to reclaim.
So re-organize the code in anon_vma_clone() slightly: first do just a
GFP_NOWAIT allocation, which will usually work fine. But if that fails,
let's just drop the lock and re-do the allocation, now with GFP_KERNEL.
End result: not only do we avoid the locking problem, this also ends up
getting better concurrency in case the allocation does need to block.
Tim Chen reports that with all these anon_vma locking tweaks, we're now
almost back up to the spinlock performance.
Reported-and-tested-by: Hugh Dickins <hughd@google.com> Tested-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andi Kleen <ak@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Peter Zijlstra [Fri, 17 Jun 2011 11:54:23 +0000 (13:54 +0200)]
mm: avoid repeated anon_vma lock/unlock sequences in unlink_anon_vmas()
This matches the anon_vma_clone() case, and uses the same lock helper
functions. Because of the need to potentially release the anon_vma's,
it's a bit more complex, though.
We traverse the 'vma->anon_vma_chain' in two phases: the first loop gets
the anon_vma lock (with the helper function that only takes the lock
once for the whole loop), and removes any entries that don't need any
more processing.
The second phase just traverses the remaining list entries (without
holding the anon_vma lock), and does any actual freeing of the
anon_vma's that is required.
Signed-off-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Hugh Dickins <hughd@google.com> Tested-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: Andi Kleen <ak@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Fri, 17 Jun 2011 03:44:51 +0000 (20:44 -0700)]
mm: avoid repeated anon_vma lock/unlock sequences in anon_vma_clone()
In anon_vma_clone() we traverse the vma->anon_vma_chain of the source
vma, locking the anon_vma for each entry.
But they are all going to have the same root entry, which means that
we're locking and unlocking the same lock over and over again. Which is
expensive in locked operations, but can get _really_ expensive when that
root entry sees any kind of lock contention.
In fact, Tim Chen reports a big performance regression due to this: when
we switched to use a mutex instead of a spinlock, the contention case
gets much worse.
So to alleviate this all, this commit creates a small helper function
(lock_anon_vma_root()) that can be used to take the lock just once
rather than taking and releasing it over and over again.
We still have the same "take the lock and release" it behavior in the
exit path (in unlink_anon_vmas()), but that one is a bit harder to fix
since we're actually freeing the anon_vma entries as we go, and that
will touch the lock too.
Reported-and-tested-by: Tim Chen <tim.c.chen@linux.intel.com> Tested-by: Hugh Dickins <hughd@google.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Andi Kleen <ak@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel J Blueman [Fri, 17 Jun 2011 18:32:19 +0000 (11:32 -0700)]
drm/i915: Fix gen6 (SNB) missed BLT ring interrupts.
The failure appeared in dmesg as:
[drm:i915_hangcheck_ring_idle] *ERROR* Hangcheck timer elapsed... blt
ring idle [waiting on 35064155, at 35064155], missed IRQ?
This works around that problem on by making the blitter command
streamer write interrupt state to the Hardware Status Page when a
MI_USER_INTERRUPT command is decoded, which appears to force the seqno
out to memory before the interrupt happens.
v1->v2: Moved to prior interrupt handler installation and RMW flags as
per feedback.
v2->v3: Removed RMW of flags (by anholt)
Cc: stable@kernel.org Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com> Signed-off-by: Eric Anholt <eric@anholt.net> Tested-by: Chris Wilson <chris@chris-wilson.co.uk> [v1] Tested-by: Eric Anholt <eric@anholt.net> [v1,v3]
(incidence of the bug with a testcase went from avg 2/1000 to
0/12651 in the latest test run (plus more for v1)) Tested-by: Kenneth Graunke <kenneth@whitecape.org> [v1] Tested-by: Robert Hooker <robert.hooker@canonical.com> [v1]
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=33394 Signed-off-by: Dave Airlie <airlied@redhat.com>
Linus Torvalds [Fri, 17 Jun 2011 17:36:32 +0000 (10:36 -0700)]
Merge branches 'gpio/merge' and 'spi/merge' of git://git.secretlab.ca/git/linux-2.6
* 'gpio/merge' of git://git.secretlab.ca/git/linux-2.6:
gpio: add GPIOF_ values regardless on kconfig settings
gpio: include linux/gpio.h where needed
gpio/omap4: Fix missing interrupts during device wakeup due to IOPAD.
* 'spi/merge' of git://git.secretlab.ca/git/linux-2.6:
spi/bfin_spi: fix handling of default bits per word setting
David Howells [Fri, 17 Jun 2011 10:25:59 +0000 (11:25 +0100)]
KEYS/DNS: Fix ____call_usermodehelper() to not lose the session keyring
____call_usermodehelper() now erases any credentials set by the
subprocess_inf::init() function. The problem is that commit 17f60a7da150 ("capabilites: allow the application of capability limits
to usermode helpers") creates and commits new credentials with
prepare_kernel_cred() after the call to the init() function. This wipes
all keyrings after umh_keys_init() is called.
The best way to deal with this is to put the init() call just prior to
the commit_creds() call, and pass the cred pointer to init(). That
means that umh_keys_init() and suchlike can modify the credentials
_before_ they are published and potentially in use by the rest of the
system.
This prevents request_key() from working as it is prevented from passing
the session keyring it set up with the authorisation token to
/sbin/request-key, and so the latter can't assume the authority to
instantiate the key. This causes the in-kernel DNS resolver to fail
with ENOKEY unconditionally.
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Eric Paris <eparis@redhat.com> Tested-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Frysinger [Fri, 17 Jun 2011 08:35:37 +0000 (04:35 -0400)]
spi/bfin_spi: fix handling of default bits per word setting
The default bits per word setting should be 8 bits, but since most of our
devices have been explicitly setting this up, we didn't notice when the
default stopped working.
At the moment, any default transfers without an explicit bit size setting
error out with:
bfin-spi bfin-spi.0: transfer: unsupported bits_per_word
So in the transfer logic, have a bits_per_word setting of 0 fall into the
8 bit transfer logic.
Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Takashi Iwai [Fri, 17 Jun 2011 12:23:46 +0000 (14:23 +0200)]
ALSA: hda - Fix no NID error with VIA codecs
The via driver spews warnigs like
hda-codec: no NID for mapping control Independent HP:0:0
with some codecs because snd_hda_add_nid() is called with nid=0.
This patch fixes it by skipping the call when no corresponding widget
is found.
Clemens Ladisch [Fri, 17 Jun 2011 06:18:35 +0000 (08:18 +0200)]
ALSA: isight: adjust for new queueing API
Since commit 13882a82ee16 (optimize iso queueing by setting
wake only after the last packet), drivers are required to call
fw_iso_context_queue_flush() after queueing a batch of packets.
The missing call would have an effect only if the controller
queue underruns, but then the DMA would stop completely.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Takao Indoh [Tue, 29 Mar 2011 16:35:04 +0000 (12:35 -0400)]
generic-ipi: Fix kexec boot crash by initializing call_single_queue before enabling interrupts
There is a problem that kdump(2nd kernel) sometimes hangs up due
to a pending IPI from 1st kernel. Kernel panic occurs because IPI
comes before call_single_queue is initialized.
To fix the crash, rename init_call_single_data() to call_function_init()
and call it in start_kernel() so that call_single_queue can be
initialized before enabling interrupts.
The details of the crash are:
(1) 2nd kernel boots up
(2) A pending IPI from 1st kernel comes when irqs are first enabled
in start_kernel().
(3) Kernel tries to handle the interrupt, but call_single_queue
is not initialized yet at this point. As a result, in the
generic_smp_call_function_single_interrupt(), NULL pointer
dereference occurs when list_replace_init() tries to access
&q->list.next.
Therefore this patch changes the name of init_call_single_data()
to call_function_init() and calls it before local_irq_enable()
in start_kernel().
Signed-off-by: Takao Indoh <indou.takao@jp.fujitsu.com> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Milton Miller <miltonm@bga.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: kexec@lists.infradead.org Link: http://lkml.kernel.org/r/D6CBEE2F420741indou.takao@jp.fujitsu.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
Linus Torvalds [Fri, 17 Jun 2011 00:54:41 +0000 (17:54 -0700)]
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:
drm/radeon/kms: use helper functions for fence read/write
drm/radeon/kms: set DP link config properly for DP bridges
drm/radeon/kms/atom: AdjustPixelClock fixes for DP bridges
drm/radeon/kms: fix handling of DP to LVDS bridges
drm/radeon/kms: issue blank/unblank commands for ext encoders
drm/radeon/kms: fix support for DDC on dp bridges
drm/radeon/kms: add support for load detection on dp bridges
drm/radeon/kms: add missing external encoder action
drm/radeon/kms: rework atombios_get_encoder_mode()
drm/radeon/kms: fix num crtcs for Cedar and Caicos
Revert "drm/i915: Enable GMBUS for post-gen2 chipsets"
drivers/gpu/drm: use printk_ratelimited instead of printk_ratelimit
drm/radeon: workaround a hw bug on some radeon chipsets with all-0 EDIDs.
drm: make debug levels match in edid failure code.
drm/radeon/kms: clear wb memory by default
drm/radeon/kms: be more pedantic about the g5 quirk (v2)
drm/radeon/kms: signed fix for evergreen thermal
drm: populate irq_by_busid-member for pci
Alex Deucher [Mon, 13 Jun 2011 21:39:06 +0000 (17:39 -0400)]
drm/radeon/kms: use helper functions for fence read/write
The existing code assumed scratch registers in a number
of places while in most cases we are be using writeback
and events rather than scratch registers.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
Jean Delvare [Sat, 4 Jun 2011 19:34:56 +0000 (19:34 +0000)]
Revert "drm/i915: Enable GMBUS for post-gen2 chipsets"
Revert commit 8f9a3f9b63b8cd3f03be9dc53533f90bd4120e5f. This fixes a
hang when loading the eeprom driver (see bug #35572.) GMBUS will be
re-enabled later, differently.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Reported-by: Marek Otahal <markotahal@gmail.com> Tested-by: Yermandu Patapitafious <yermandu.dev@gmail.com> Tested-by: Andrew Lutomirski <luto@mit.edu> Acked-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Dave Airlie <airlied@redhat.com>
Paul E. McKenney [Thu, 16 Jun 2011 15:26:32 +0000 (08:26 -0700)]
rcu: Move RCU_BOOST #ifdefs to header file
The commit "use softirq instead of kthreads except when RCU_BOOST=y"
just applied #ifdef in place. This commit is a cleanup that moves
the newly #ifdef'ed code to the header file kernel/rcutree_plugin.h.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[CPUFREQ] powernow-k8: Don't notify of successful transition if we failed (vid case).
Before this patch if we failed the vid transition would still try to
submit the "new" frequencies to cpufreq.
That is incorrect - also we could submit a non-existing frequency value
which would cause cpufreq to crash. The ultimate fix is in cpufreq
to deal with incorrect values, but this patch improves the error
recovery in the AMD powernowk8 driver.
The failure that was reported was as follows:
powernow-k8: Found 1 AMD Athlon(tm) 64 Processor 3700+ (1 cpu cores) (version 2.20.00)
powernow-k8: fid 0x2 (1000 MHz), vid 0x12
powernow-k8: fid 0xa (1800 MHz), vid 0xa
powernow-k8: fid 0xc (2000 MHz), vid 0x8
powernow-k8: fid 0xe (2200 MHz), vid 0x8
Marking TSC unstable due to cpufreq changes
powernow-k8: fid trans failed, fid 0x2, curr 0x0
BUG: unable to handle kernel paging request at ffff880807e07b78
IP: [<ffffffff81479163>] cpufreq_stats_update+0x46/0x5b
...
And transition fails and data->currfid ends up with 0. Since
the machine does not support 800Mhz value when the calculation is
done ('find_khz_freq_from_fid(data->currfid);') it reports the
new frequency as 800000 which is bogus. This patch fixes
the issue during target setting.
The patch however does not fix the issue in 'powernowk8_cpu_init'
where the pol->cur can also be set with the 800000 value:
pol->cur = find_khz_freq_from_fid(data->currfid);
dprintk("policy current frequency %d kHz\n", pol->cur);
/* min/max the cpu is capable of */
if (cpufreq_frequency_table_cpuinfo(pol, data->powernow_table)) {
The fix for that looks to update cpufreq_frequency_table_cpuinfo to
check pol->cur.... but that would cause an regression in how the
acpi-cpufreq driver works (it sets cpu->cur after calling
cpufreq_frequency_table_cpuinfo). Instead the fix will be to let
cpufreq gracefully handle bogus data (another patch).
Acked-by: Borislav Petkov <bp@alien8.de> CC: andre.przywara@amd.com CC: Mark.Langsdorf@amd.com Reported-by: Tobias Diedrich <ranma+xen@tdiedrich.de> Tested-by: Tobias Diedrich <ranma+xen@tdiedrich.de>
[v1: Rebased on v3.0-rc2, reduced patch to deal with vid case] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Dave Jones <davej@redhat.com>
[CPUFREQ] Don't set stat->last_index to -1 if the pol->cur has incorrect value.
If the driver submitted an non-existing pol>cur value (say it
used the default initialized value of zero), when the cpufreq
stats tries to setup its initial values it incorrectly sets
stat->last_index to -1 (or 0xfffff...). And cpufreq_stats_update
tries to update at that index location and fails.
not finding the appropiate frequency in the table (b/c the policy->cur
is wrong) and we end up crashing. The fix however is
concentrated in the 'cpufreq_stats_update' as the last_index
(and old_index) are updated there. Which means it can reset
the last_index to -1 again and on the next iteration cause a crash.
Without this patch, the following crash is observed:
powernow-k8: Found 1 AMD Athlon(tm) 64 Processor 3700+ (1 cpu cores) (version 2.20.00)
powernow-k8: fid 0x2 (1000 MHz), vid 0x12
powernow-k8: fid 0xa (1800 MHz), vid 0xa
powernow-k8: fid 0xc (2000 MHz), vid 0x8
powernow-k8: fid 0xe (2200 MHz), vid 0x8
Marking TSC unstable due to cpufreq changes
powernow-k8: fid trans failed, fid 0x2, curr 0x0
BUG: unable to handle kernel paging request at ffff880807e07b78
IP: [<ffffffff81479163>] cpufreq_stats_update+0x46/0x5b
.. snip..
Pid: 1, comm: swapper Not tainted 3.0.0-rc2 #45 MICRO-STAR INTERNATIONAL CO., LTD MS-7094/MS-7094
..snip..
Call Trace:
[<ffffffff81479248>] cpufreq_stat_notifier_trans+0x48/0x7c
[<ffffffff81095d68>] notifier_call_chain+0x32/0x5e
[<ffffffff81095e6b>] __srcu_notifier_call_chain+0x47/0x63
[<ffffffff81095e96>] srcu_notifier_call_chain+0xf/0x11
[<ffffffff81477e7a>] cpufreq_notify_transition+0x111/0x134
[<ffffffff8147b0d4>] powernowk8_target+0x53b/0x617
[<ffffffff8147723a>] __cpufreq_driver_target+0x2e/0x30
[<ffffffff8147a127>] cpufreq_governor_dbs+0x339/0x356
[<ffffffff81477394>] __cpufreq_governor+0xa8/0xe9
[<ffffffff81477525>] __cpufreq_set_policy+0x132/0x13e
[<ffffffff8147848d>] cpufreq_add_dev_interface+0x272/0x28c
Reported-by: Tobias Diedrich <ranma+xen@tdiedrich.de> Tested-by: Tobias Diedrich <ranma+xen@tdiedrich.de> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Dave Jones <davej@redhat.com>
Torsten Schenk [Thu, 16 Jun 2011 19:06:27 +0000 (21:06 +0200)]
ALSA: 6fire - Fix signedness bug
Fixed remaining issues of the signedness bug discovered by Dan Carpenter.
A check was remaining that tests if unsigned rt->rate is >= 0.
Changed that so that rt->rate now consistently uses ARRAY_SIZE(rates)
as invalid rate value and not -1.
Thomas Gleixner [Thu, 16 Jun 2011 14:22:08 +0000 (16:22 +0200)]
clocksource: Make watchdog robust vs. interruption
The clocksource watchdog code is interruptible and it has been
observed that this can trigger false positives which disable the TSC.
The reason is that an interrupt storm or a long running interrupt
handler between the read of the watchdog source and the read of the
TSC brings the two far enough apart that the delta is larger than the
unstable treshold. Move both reads into a short interrupt disabled
region to avoid that.
Reported-and-tested-by: Vernon Mauery <vernux@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org
Linus Torvalds [Thu, 16 Jun 2011 17:26:58 +0000 (10:26 -0700)]
Merge branch 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6
* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild-2.6:
kbuild: Call depmod.sh via shell
perf: clear out make flags when calling kernel make kernelver
Linus Torvalds [Thu, 16 Jun 2011 17:21:59 +0000 (10:21 -0700)]
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:
AFS: Use i_generation not i_version for the vnode uniquifier
AFS: Set s_id in the superblock to the volume name
vfs: Fix data corruption after failed write in __block_write_begin()
afs: afs_fill_page reads too much, or wrong data
VFS: Fix vfsmount overput on simultaneous automount
fix wrong iput on d_inode introduced by e6bc45d65d
Delay struct net freeing while there's a sysfs instance refering to it
afs: fix sget() races, close leak on umount
ubifs: fix sget races
ubifs: split allocation of ubifs_info into a separate function
fix leak in proc_set_super()
Linus Torvalds [Thu, 16 Jun 2011 16:44:20 +0000 (09:44 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
SELinux: skip file_name_trans_write() when policy downgraded.
selinux: fix case of names with whitespace/multibytes on /selinux/create
There's no reason not to support cache flushing on external log devices.
The only thing this really requires is flushing the data device first
both in fsync and log commits. A side effect is that we also have to
remove the barrier write test during mount, which has been superflous
since the new FLUSH+FUA code anyway. Also use the chance to flush the
RT subvolume write cache before the fsync commit, which is required
for correct semantics.
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
David Howells [Mon, 13 Jun 2011 23:45:44 +0000 (00:45 +0100)]
AFS: Use i_generation not i_version for the vnode uniquifier
Store the AFS vnode uniquifier in the i_generation field, not the i_version
field of the inode struct. i_version can then be given the AFS data version
number.
Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Jan Kara [Mon, 13 Jun 2011 22:58:27 +0000 (00:58 +0200)]
vfs: Fix data corruption after failed write in __block_write_begin()
I've got a report of a file corruption from fsxlinux on ext3. The important
operations to the page were:
mapwrite to a hole
partial write to the page
read - found the page zeroed from the end of the normal write
The culprit seems to be that if get_block() fails in __block_write_begin()
(e.g. transient ENOSPC in ext3), the function does ClearPageUptodate(page).
Thus when we retry the write, the logic in __block_write_begin() thinks zeroing
of the page is needed and overwrites old data. In fact, I don't see why we
should ever need to zero the uptodate bit here - either the page was uptodate
when we entered __block_write_begin() and it should stay so when we leave it,
or it was not uptodate and noone had right to set it uptodate during
__block_write_begin() so it remains !uptodate when we leave as well. So just
remove clearing of the bit.
Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Anton Blanchard [Mon, 13 Jun 2011 21:31:12 +0000 (22:31 +0100)]
afs: afs_fill_page reads too much, or wrong data
afs_fill_page should read the page that is about to be written but
the current implementation has a number of issues. If we aren't
extending the file we always read PAGE_CACHE_SIZE at offset 0. If we
are extending the file we try to read the entire file.
Change afs_fill_page to read PAGE_CACHE_SIZE at the right offset,
clamped to i_size.
While here, avoid calling afs_fill_page when we are doing a
PAGE_CACHE_SIZE write.
Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Randy Dunlap [Tue, 14 Jun 2011 22:00:18 +0000 (15:00 -0700)]
staging: fix iio builds when IIO_RING_BUFFER is not enabled
Fix build by moving enum list outside of
#ifdef CONFIG_IIO_RING_BUFFER.
drivers/staging/iio/accel/adis16201_core.c:413: error: 'ADIS16201_SCAN_SUPPLY' undeclared here (not in a function)
drivers/staging/iio/accel/adis16201_core.c:417: error: 'ADIS16201_SCAN_TEMP' undeclared here (not in a function)
..
drivers/staging/iio/accel/adis16203_core.c:374: error: 'ADIS16203_SCAN_SUPPLY' undeclared here (not in a function)
drivers/staging/iio/accel/adis16203_core.c:378: error: 'ADIS16203_SCAN_AUX_ADC' undeclared here (not in a function)
..
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Jonathan Cameron <jic23@cam.ac.uk> Cc: linux-iio@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Al Viro [Thu, 16 Jun 2011 14:10:06 +0000 (15:10 +0100)]
VFS: Fix vfsmount overput on simultaneous automount
[Kudos to dhowells for tracking that crap down]
If two processes attempt to cause automounting on the same mountpoint at the
same time, the vfsmount holding the mountpoint will be left with one too few
references on it, causing a BUG when the kernel tries to clean up.
The problem is that lock_mount() drops the caller's reference to the
mountpoint's vfsmount in the case where it finds something already mounted on
the mountpoint as it transits to the mounted filesystem and replaces path->mnt
with the new mountpoint vfsmount.
During a pathwalk, however, we don't take a reference on the vfsmount if it is
the same as the one in the nameidata struct, but do_add_mount() doesn't know
this.
The fix is to make sure we have a ref on the vfsmount of the mountpoint before
calling do_add_mount(). However, if lock_mount() doesn't transit, we're then
left with an extra ref on the mountpoint vfsmount which needs releasing.
We can handle that in follow_managed() by not making assumptions about what
we can and what we cannot get from lookup_mnt() as the current code does.
The callers of follow_managed() expect that reference to path->mnt will be
grabbed iff path->mnt has been changed. follow_managed() and follow_automount()
keep track of whether such reference has been grabbed and assume that it'll
happen in those and only those cases that'll have us return with changed
path->mnt. That assumption is almost correct - it breaks in case of
racing automounts and in even harder to hit race between following a mountpoint
and a couple of mount --move. The thing is, we don't need to make that
assumption at all - after the end of loop in follow_manage() we can check
if path->mnt has ended up unchanged and do mntput() if needed.
The BUG can be reproduced with the following test program:
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <sys/wait.h>
int main(int argc, char **argv)
{
int pid, ws;
struct stat buf;
pid = fork();
stat(argv[1], &buf);
if (pid > 0) wait(&ws);
return 0;
}
and the following procedure:
(1) Mount an NFS volume that on the server has something else mounted on a
subdirectory. For instance, I can mount / from my server:
mount warthog:/ /mnt -t nfs4 -r
On the server /data has another filesystem mounted on it, so NFS will see
a change in FSID as it walks down the path, and will mark /mnt/data as
being a mountpoint. This will cause the automount code to be triggered.
!!! Do not look inside the mounted fs at this point !!!
(2) Run the above program on a file within the submount to generate two
simultaneous automount requests:
/tmp/forkstat /mnt/data/testfile
(3) Unmount the automounted submount:
umount /mnt/data
(4) Unmount the original mount:
umount /mnt
At this point the kernel should throw a BUG with something like the
following:
BUG: Dentry ffff880032e3c5c0{i=2,n=} still in use (1) [unmount of nfs4 0:12]
Note that the bug appears on the root dentry of the original mount, not the
mountpoint and not the submount because sys_umount() hasn't got to its final
mntput_no_expire() yet, but this isn't so obvious from the call trace:
as do_umount() is inlined. However, you can see release_mounts() in there.
Note also that it may be necessary to have multiple CPU cores to be able to
trigger this bug.
Tested-by: Jeff Layton <jlayton@redhat.com> Tested-by: Ian Kent <raven@themaw.net> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
A reliable way to reproduce this bug is:
Login to KDE, run 'rsnapshot sync', and apt-get install openjdk-6-jdk,
and apt-get remove openjdk-6-jdk.
The buggy part of the patch is this:
struct inode *inode = NULL;
.....
- if (nd.last.name[nd.last.len])
- goto slashes;
inode = dentry->d_inode;
- if (inode)
- ihold(inode);
+ if (nd.last.name[nd.last.len] || !inode)
+ goto slashes;
+ ihold(inode)
...
if (inode)
iput(inode); /* truncate the inode here */
If nd.last.name[nd.last.len] is nonzero (and thus goto slashes branch is taken),
and dentry->d_inode is non-NULL, then this code now does an additional iput on
the inode, which is wrong.
Fix this by only setting the inode variable if nd.last.name[nd.last.len] is 0.
Reference: https://lkml.org/lkml/2011/6/15/50 Reported-by: Norbert Preining <preining@logic.at> Reported-by: Török Edwin <edwintorok@gmail.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Török Edwin <edwintorok@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Randy Dunlap [Wed, 15 Jun 2011 00:05:11 +0000 (17:05 -0700)]
gpio: add GPIOF_ values regardless on kconfig settings
Make GPIOF_ defined values available even when GPIOLIB nor GENERIC_GPIO
is enabled by moving them to <linux/gpio.h>.
Fixes these build errors in linux-next:
sound/soc/codecs/ak4641.c:524: error: 'GPIOF_OUT_INIT_LOW' undeclared (first use in this function)
sound/soc/codecs/wm8915.c:2921: error: 'GPIOF_OUT_INIT_LOW' undeclared (first use in this function)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Randy Dunlap [Wed, 15 Jun 2011 00:06:02 +0000 (17:06 -0700)]
gpio: include linux/gpio.h where needed
Some files use GPIOF_ macros but don't include the header file
for them. These macros are being moved to <linux/gpio.h>, so add
includes for <linux/gpio.h> where needed.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Ambresh K [Wed, 15 Jun 2011 20:40:45 +0000 (13:40 -0700)]
gpio/omap4: Fix missing interrupts during device wakeup due to IOPAD.
If gpio pins from bank[2-5] are marked as wakeup enable and if the wake is
through gpio IO pad wakeup, then that wakeup gpio interrupt is lost.
In the current implementation, GPIO driver stores the context of DATAIN of
all the gpio in the bank. During GPIO resuming, it checks DATAIN with wakeup
enabled pins of gpio bank. If there is status change, then manually toggle
GPIO_LEVELDETECT to generate pseudo interrupt.
Reported-by: Philippe Mazet <p-mazet@ti.com> Tested-by: Philippe Mazet <p-mazet@ti.com> Signed-off-by: Ambresh K <ambresh@ti.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
It turned out that the actual reason for failure is not the device
firmware, but bug in Bluetooth stack, which will be fixed by
patch by Ville Tervo which corrects the mask handling for CSR 1.1
Dongles.
Reported-and-tested-by: Ed Tomlinson <edt@aei.ca> Reported-and-tested-by: Chase Douglas <chase.douglas@canonical.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Mathias Krause [Wed, 15 Jun 2011 21:03:38 +0000 (23:03 +0200)]
tools/perf: Fix static build of perf tool
To build a statically linked version of the perf tool all needed
libraries must be added in the correct order to get the symbols
resolved. Currently this is broken when, e.g. python or newt
support is enabled -- libpython needs libpthread which is an
unconditional link dependency of the perf tool; libslang needs
libm, another unconditional dependency. To solve the problem in
the long run without the need to keep track of transitive
library dependencies, simply make the linker look at the EXTLIBS
multiple times until it has all symbols resolved.
Linus Torvalds [Thu, 16 Jun 2011 07:35:09 +0000 (00:35 -0700)]
mm: get rid of the most spurious find_vma_prev() users
We have some users of this function that date back to before the vma
list was doubly linked, and just are silly. These days, you can find
the previous vma by just following the vma->vm_prev pointer.
In some cases you don't need any find_vma() lookup at all, and in other
cases you're better off with the regular "find_vma()" that uses the vma
cache front-end lookup.
Some "find_vma_prev()" users are still valid, though. For example, in
the case of a stack that grows up, it can be the case that we don't find
any 'vma' at all (because we're looking up an address that is past the
last vma), and that the stack that we want to grow is the 'prev' vma.
But that kind of special case aside, we generally should prefer to use
'find_vma()'.
Noticed due to a totally unrelated POWER memory corruption bug that just
happened to hit in 'find_vma_prev()' and made me go "Hmm - why are we
using that function here?".
Dave Airlie [Tue, 14 Jun 2011 06:13:55 +0000 (06:13 +0000)]
drm/radeon: workaround a hw bug on some radeon chipsets with all-0 EDIDs.
Some RS690 chipsets seem to end up with floating connectors, either
a DVI connector isn't actually populated, or an add-in HDMI card
is available but not installed. In this case we seem to get a NULL byte
response for each byte of the i2c transaction, so we detect this
case and if we see it we don't do anymore DDC transactions on this
connector.
I've tested this on my RS690 without the HDMI card installed and
it seems to work fine.
Signed-off-by: Dave Airlie <airlied@redhat.com> Reviewed-by: Alex Deucher <alexdeucher@gmail.com>
Alex Deucher [Tue, 14 Jun 2011 15:27:38 +0000 (15:27 +0000)]
drm/radeon/kms: be more pedantic about the g5 quirk (v2)
I don't think Apple offered any other cards for
this mac, so I doubt this will be an issue, but just
to be on the safe side, check the pci ids as well.
v2: fix spelling in commit message
Reviewed-by: Michel Dänzer <michel@daenzer.net> Signed-off-by: Alex Deucher <alexdeucher@gmail.com> Cc: Joachim Henke <j-o@users.sourceforge.net> Cc: Michel Dänzer <michel@daenzer.net> Signed-off-by: Dave Airlie <airlied@redhat.com>
Wolfram Sang [Wed, 15 Jun 2011 09:26:47 +0000 (11:26 +0200)]
drm: populate irq_by_busid-member for pci
Commit 8410ea (drm: rework PCI/platform driver interface) implemented
drm_pci_irq_by_busid() but forgot to make it available in the
drm_pci_bus-struct.
This caused a freeze on my Radeon9600-equipped laptop when executing glxgears.
Thanks to Michel for noticing the flaw.
[airlied: made function static also]
Reported-by: Michel Dänzer <daenzer@vmware.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Cc: stable@kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>
Paul E. McKenney [Wed, 15 Jun 2011 22:47:09 +0000 (15:47 -0700)]
rcu: use softirq instead of kthreads except when RCU_BOOST=y
This patch #ifdefs RCU kthreads out of the kernel unless RCU_BOOST=y,
thus eliminating context-switch overhead if RCU priority boosting has
not been configured.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Linus Torvalds [Thu, 16 Jun 2011 05:01:36 +0000 (22:01 -0700)]
Merge branch 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm:
ARM: footbridge: fix clock event support
ARM: footbridge: fix debug macros
ARM: initrd: disable initrds outside of memory
ARM: extend Code: line by one 16-bit quantity for Thumb instructions
ARM: 6955/1: cmpxchg syscall should data abort if page not write
ARM: 6954/1: zImage: fix Thumb2 breakage
ARM: 6953/1: DT: don't try to access physical address zero
ARM: 6949/2: mach-u300: fix compilaton warning in IO accessors
Revert "ARM: 6944/1: mm: allow ASID 0 to be allocated to tasks"
Revert "ARM: 6943/1: mm: use TTBR1 instead of reserved context ID"
davinci: make PCM platform devices static
arm: davinci: Fix fallout from generic irq chip conversion
ARM: 6894/1: mmci: trigger card detect IRQs on falling and rising edges
ARM: 6952/1: fix lockdep warning of "unannotated irqs-off"
ARM: 6951/1: include .bss in memory layout information
ARM: 6948/1: Fix .size directives for __arm{7,9}tdmi_proc_info
ARM: 6947/2: mach-u300: fix compilation error in timer
ARM: 6946/1: vexpress: move v2m clock init to init_early
ARM: mx51/sdma: Check the chip revision in run-time
arm: mxs: include asm/processor.h for cpu_relax()
(yes, seriously: two different #define's for that thing, with the first
one being inside an "#ifdef TIF_IA32")
It's possible that it is UML that should just be fixed in this area, but
for now let's just undo the (very small) optimization.
Reported-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Richard Weinberger <richard@nod.at> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jörg Sommer [Wed, 15 Jun 2011 19:59:45 +0000 (12:59 -0700)]
Documentation: update cgroupfs mount point
According to commit 676db4af0430 ("cgroupfs: create /sys/fs/cgroup to
mount cgroupfs on") the canonical mountpoint for the cgroup filesystem
is /sys/fs/cgroup. Hence, this should be used in the documentation.
Signed-off-by: Jörg Sommer <joerg@alea.gnuu.de> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Maxin B. John [Wed, 15 Jun 2011 19:58:29 +0000 (12:58 -0700)]
Documentation: update kmemleak supported archs
Instead of listing the architectures that are supported by
kmemleak in Documentation/kmemleak.txt, just refer people to
the list of supported architecutures in lib/Kconfig.debug so
that Documentation/kmemleak.txt does not need more updates
for this.
Signed-off-by: Maxin B. John <maxin.john@gmail.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Thu, 16 Jun 2011 04:45:18 +0000 (21:45 -0700)]
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Check if lowest_mask is initialized in find_lowest_rq()
sched: Fix need_resched() when checking peempt
Dan Rosenberg [Wed, 15 Jun 2011 22:09:01 +0000 (15:09 -0700)]
alpha: fix several security issues
Fix several security issues in Alpha-specific syscalls. Untested, but
mostly trivial.
1. Signedness issue in osf_getdomainname allows copying out-of-bounds
kernel memory to userland.
2. Signedness issue in osf_sysinfo allows copying large amounts of
kernel memory to userland.
3. Typo (?) in osf_getsysinfo bounds minimum instead of maximum copy
size, allowing copying large amounts of kernel memory to userland.
4. Usage of user pointer in osf_wait4 while under KERNEL_DS allows
privilege escalation via writing return value of sys_wait4 to kernel
memory.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh Dickins [Wed, 15 Jun 2011 22:08:58 +0000 (15:08 -0700)]
ksm: fix NULL pointer dereference in scan_get_next_rmap_item()
Andrea Righi reported a case where an exiting task can race against
ksmd::scan_get_next_rmap_item (http://lkml.org/lkml/2011/6/1/742) easily
triggering a NULL pointer dereference in ksmd.
ksm_scan.mm_slot == &ksm_mm_head with only one registered mm
CPU 1 (__ksm_exit) CPU 2 (scan_get_next_rmap_item)
list_empty() is false
lock slot == &ksm_mm_head
list_del(slot->mm_list)
(list now empty)
unlock
lock
slot = list_entry(slot->mm_list.next)
(list is empty, so slot is still ksm_mm_head)
unlock
slot->mm == NULL ... Oops
Close this race by revalidating that the new slot is not simply the list
head again.
Nils Carlson [Wed, 15 Jun 2011 22:08:54 +0000 (15:08 -0700)]
drivers/char/hpet.c: fix periodic-emulation for delayed interrupts
When interrupts are delayed due to interrupt masking or due to other
interrupts being serviced the HPET periodic-emuation would fail. This
happened because given an interval t and a time for the current interrupt
m we would compute the next time as t + m. This works until we are
delayed for > t, in which case we would be writing a new value which is in
fact in the past.
This can be solved by computing the next time instead as (k * t) + m where
k is large enough to be in the future. The exact computation of k is
described in a comment to the code.
More detail:
Assuming an interval of 5 between each expected interrupt we have a normal
case of
t0: interrupt, read t0 from comparator, set next interrupt t0 + 5
t5: interrupt, read t5 from comparator, set next interrupt t5 + 5
t10: interrupt, read t10 from comparator, set next interrupt t10 + 5
...
So, what happens when the interrupt is serviced too late?
t0: interrupt, read t0 from comparator, set next interrupt t0 + 5
t11: delayed interrupt serviced, read t5 from comparator, set next
interrupt t5 + 5, which is in the past!
... counter loops ...
t10: Much much later, get the next interrupt.
This can happen either because we have interrupts masked for too long
(some stupid driver goes on a printk rampage) or just because we are
pushing the limits of the interval (too small a period), or both most
probably.
My solution is to read the main counter as well and set the next interrupt
to occur at the right interval, for example:
t0: interrupt, read t0 from comparator, set next interrupt t0 + 5
t11: delayed interrupt serviced, read t5 from comparator, set next
interrupt t15 as t10 has been missed.
t15: back on track.
Signed-off-by: Nils Carlson <nils.carlson@ericsson.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Wed, 15 Jun 2011 22:08:52 +0000 (15:08 -0700)]
mm: compaction: abort compaction if too many pages are isolated and caller is asynchronous V2
Asynchronous compaction is used when promoting to huge pages. This is all
very nice but if there are a number of processes in compacting memory, a
large number of pages can be isolated. An "asynchronous" process can
stall for long periods of time as a result with a user reporting that
firefox can stall for 10s of seconds. This patch aborts asynchronous
compaction if too many pages are isolated as it's better to fail a
hugepage promotion than stall a process.
[minchan.kim@gmail.com: return COMPACT_PARTIAL for abort] Reported-and-tested-by: Ury Stankevich <urykhy@gmail.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrea Arcangeli [Wed, 15 Jun 2011 22:08:51 +0000 (15:08 -0700)]
mm: vmscan: do not use page_count without a page pin
It is unsafe to run page_count during the physical pfn scan because
compound_head could trip on a dangling pointer when reading
page->first_page if the compound page is being freed by another CPU.
[mgorman@suse.de: split out patch] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Michal Hocko <mhocko@suse.cz> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mel Gorman [Wed, 15 Jun 2011 22:08:50 +0000 (15:08 -0700)]
mm: compaction: ensure that the compaction free scanner does not move to the next zone
Compaction works with two scanners, a migration and a free scanner. When
the scanners crossover, migration within the zone is complete. The
location of the scanner is recorded on each cycle to avoid excesive
scanning.
When a zone is small and mostly reserved, it's very easy for the migration
scanner to be close to the end of the zone. Then the following situation
can occurs
o migration scanner isolates some pages near the end of the zone
o free scanner starts at the end of the zone but finds that the
migration scanner is already there
o free scanner gets reinitialised for the next cycle as
cc->migrate_pfn + pageblock_nr_pages
moving the free scanner into the next zone
o migration scanner moves into the next zone
When this happens, NR_ISOLATED accounting goes haywire because some of the
accounting happens against the wrong zone. One zones counter remains
positive while the other goes negative even though the overall global
count is accurate. This was reported on X86-32 with !SMP because !SMP
allows the negative counters to be visible. The fact that it is the bug
should theoritically be possible there.
Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
projects / mirror_ubuntu-disco-kernel.git / log