22 Nov, 2011
15 commits
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Signed-off-by: Tejun Heo
Cc: Arnd Bergmann
Cc: linux-arch@vger.kernel.org -
Using TIF_FREEZE for freezing worked when there was only single
freezing condition (the PM one); however, now there is also the
cgroup_freezer and single bit flag is getting clumsy.
thaw_processes() is already testing whether cgroup freezing in in
effect to avoid thawing tasks which were frozen by both PM and cgroup
freezers.This is racy (nothing prevents race against cgroup freezing) and
fragile. A much simpler way is to test actual freeze conditions from
freezing() - ie. directly test whether PM or cgroup freezing is in
effect.This patch adds variables to indicate whether and what type of
freezing conditions are in effect and reimplements freezing() such
that it directly tests whether any of the two freezing conditions is
active and the task should freeze. On fast path, freezing() is still
very cheap - it only tests system_freezing_cnt.This makes the clumsy dancing aroung TIF_FREEZE unnecessary and
freeze/thaw operations more usual - updating state variables for the
new state and nudging target tasks so that they notice the new state
and comply. As long as the nudging happens after state update, it's
race-free.* This allows use of freezing() in freeze_task(). Replace the open
coded tests with freezing().* p != current test is added to warning printing conditions in
try_to_freeze_tasks() failure path. This is necessary as freezing()
is now true for the task which initiated freezing too.-v2: Oleg pointed out that re-freezing FROZEN cgroup could increment
system_freezing_cnt. Fixed.Signed-off-by: Tejun Heo
Acked-by: Paul Menage (for the cgroup portions) -
TIF_FREEZE will be removed soon and freezing() will directly test
whether any freezing condition is in effect. Make the following
changes in preparation.* Rename cgroup_freezing_or_frozen() to cgroup_freezing() and make it
return bool.* Make cgroup_freezing() access task_freezer() under rcu read lock
instead of task_lock(). This makes the state dereferencing racy
against task moving to another cgroup; however, it was already racy
without this change as ->state dereference wasn't synchronized.
This will be later dealt with using attach hooks.* freezer->state is now set before trying to push tasks into the
target state.-v2: Oleg pointed out that freeze_change_state() was setting
freeze->state incorrectly to CGROUP_FROZEN instead of
CGROUP_FREEZING. Fixed.-v3: Matt pointed out that setting CGROUP_FROZEN used to always invoke
try_to_freeze_cgroup() regardless of the current state. Patch
updated such that the actual freeze/thaw operations are always
performed on invocation. This shouldn't make any difference
unless something is broken.Signed-off-by: Tejun Heo
Acked-by: Paul Menage
Cc: Li Zefan
Cc: Oleg Nesterov -
freeze_processes() failure path is rather messy. Freezing is canceled
for workqueues and tasks which aren't frozen yet but frozen tasks are
left alone and should be thawed by the caller and of course some
callers (xen and kexec) didn't do it.This patch updates __thaw_task() to handle cancelation correctly and
makes freeze_processes() and freeze_kernel_threads() call
thaw_processes() on failure instead so that the system is fully thawed
on failure. Unnecessary [suspend_]thaw_processes() calls are removed
from kernel/power/hibernate.c, suspend.c and user.c.While at it, restructure error checking if clause in suspend_prepare()
to be less weird.-v2: Srivatsa spotted missing removal of suspend_thaw_processes() in
suspend_prepare() and error in commit message. Updated.Signed-off-by: Tejun Heo
Acked-by: Srivatsa S. Bhat -
With the previous changes, there's no meaningful difference between
PF_FREEZING and PF_FROZEN. Remove PF_FREEZING and use PF_FROZEN
instead in task_contributes_to_load().Signed-off-by: Tejun Heo
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try_to_freeze_tasks() and thaw_processes() use freezable() and
frozen() as preliminary tests before initiating operations on a task.
These are done without any synchronization and hinder with
synchronization cleanup without any real performance benefits.In try_to_freeze_tasks(), open code self test and move PF_NOFREEZE and
frozen() tests inside freezer_lock in freeze_task().thaw_processes() can simply drop freezable() test as frozen() test in
__thaw_task() is enough.Note: This used to be a part of larger patch to fix set_freezable()
race. Separated out to satisfy ordering among dependent fixes.Signed-off-by: Tejun Heo
Cc: Oleg Nesterov -
Currently freezing (TIF_FREEZE) and frozen (PF_FROZEN) states are
interlocked - freezing is set to request freeze and when the task
actually freezes, it clears freezing and sets frozen.This interlocking makes things more complex than necessary - freezing
doesn't mean there's freezing condition in effect and frozen doesn't
match the task actually entering and leaving frozen state (it's
cleared by the thawing task).This patch makes freezing indicate that freeze condition is in effect.
A task enters and stays frozen if freezing. This makes PF_FROZEN
manipulation done only by the task itself and prevents wakeup from
__thaw_task() leaking outside of refrigerator.The only place which needs to tell freezing && !frozen is
try_to_freeze_task() to whine about tasks which don't enter frozen.
It's updated to test the condition explicitly.With the change, frozen() state my linger after __thaw_task() until
the task wakes up and exits fridge. This can trigger BUG_ON() in
update_if_frozen(). Work it around by testing freezing() && frozen()
instead of frozen().-v2: Oleg pointed out missing re-check of freezing() when trying to
clear FROZEN and possible spurious BUG_ON() trigger in
update_if_frozen(). Both fixed.Signed-off-by: Tejun Heo
Cc: Oleg Nesterov
Cc: Paul Menage -
Freezer synchronization is needlessly complicated - it's by no means a
hot path and the priority is staying unintrusive and safe. This patch
makes it simply use a dedicated lock instead of piggy-backing on
task_lock() and playing with memory barriers.On the failure path of try_to_freeze_tasks(), locking is moved from it
to cancel_freezing(). This makes the frozen() test racy but the race
here is a non-issue as the warning is printed for tasks which failed
to enter frozen for 20 seconds and race on PF_FROZEN at the last
moment doesn't change anything.This simplifies freezer implementation and eases further changes
including some race fixes.Signed-off-by: Tejun Heo
-
There's no point in thawing nosig tasks before others. There's no
ordering requirement between the two groups on thaw, which the staged
thawing can't guarantee anyway. Simplify thaw_processes() by removing
the distinction and collapsing thaw_tasks() into thaw_processes().
This will help further updates to freezer.Signed-off-by: Tejun Heo
-
clear_freeze_flag() in exit_mm() is racy. Freezing can start
afterwards. Remove it. Skipping freezer for exiting task will be
properly implemented later.Also, freezable() was testing exit_state directly to make system
freezer ignore dead tasks. Let the exiting task set PF_NOFREEZE after
entering TASK_DEAD instead.Signed-off-by: Tejun Heo
Cc: Oleg Nesterov -
thaw_process() now has only internal users - system and cgroup
freezers. Remove the unnecessary return value, rename, unexport and
collapse __thaw_process() into it. This will help further updates to
the freezer code.-v3: oom_kill grew a use of thaw_process() while this patch was
pending. Convert it to use __thaw_task() for now. In the longer
term, this should be handled by allowing tasks to die if killed
even if it's frozen.-v2: minor style update as suggested by Matt.
Signed-off-by: Tejun Heo
Cc: Paul Menage
Cc: Matt Helsley -
Writeback and thinkpad_acpi have been using thaw_process() to prevent
deadlock between the freezer and kthread_stop(); unfortunately, this
is inherently racy - nothing prevents freezing from happening between
thaw_process() and kthread_stop().This patch implements kthread_freezable_should_stop() which enters
refrigerator if necessary but is guaranteed to return if
kthread_stop() is invoked. Both thaw_process() users are converted to
use the new function.Note that this deadlock condition exists for many of freezable
kthreads. They need to be converted to use the new should_stop or
freezable workqueue.Tested with synthetic test case.
Signed-off-by: Tejun Heo
Acked-by: Henrique de Moraes Holschuh
Cc: Jens Axboe
Cc: Oleg Nesterov -
There is no reason to export two functions for entering the
refrigerator. Calling refrigerator() instead of try_to_freeze()
doesn't save anything noticeable or removes any race condition.* Rename refrigerator() to __refrigerator() and make it return bool
indicating whether it scheduled out for freezing.* Update try_to_freeze() to return bool and relay the return value of
__refrigerator() if freezing().* Convert all refrigerator() users to try_to_freeze().
* Update documentation accordingly.
* While at it, add might_sleep() to try_to_freeze().
Signed-off-by: Tejun Heo
Cc: Samuel Ortiz
Cc: Chris Mason
Cc: "Theodore Ts'o"
Cc: Steven Whitehouse
Cc: Andrew Morton
Cc: Jan Kara
Cc: KONISHI Ryusuke
Cc: Christoph Hellwig -
Some drivers set PF_NOFREEZE in their kthread functions which is
completely unnecessary and racy - some part of freezer code doesn't
consider cases where PF_NOFREEZE is set asynchronous to freezer
operations.In general, there's no reason to allow setting PF_NOFREEZE explicitly.
Remove them and change the documentation to note that setting
PF_NOFREEZE directly isn't allowed.-v2: Dropped change to twl4030-irq.c as it no longer uses PF_NOFREEZE.
Signed-off-by: Tejun Heo
Acked-by: "Gustavo F. Padovan"
Acked-by: Samuel Ortiz
Cc: Marcel Holtmann
Cc: wwang -
refrigerator() saves current->state before entering frozen state and
restores it before returning using __set_current_state(); however,
this is racy, for example, please consider the following sequence.set_current_state(TASK_INTERRUPTIBLE);
try_to_freeze();
if (kthread_should_stop())
break;
schedule();If kthread_stop() races with ->state restoration, the restoration can
restore ->state to TASK_INTERRUPTIBLE after kthread_stop() sets it to
TASK_RUNNING but kthread_should_stop() may still see zero
->should_stop because there's no memory barrier between restoring
TASK_INTERRUPTIBLE and kthread_should_stop() test.This isn't restricted to kthread_should_stop(). current->state is
often used in memory barrier based synchronization and silently
restoring it w/o mb breaks them.Use set_current_state() instead.
Signed-off-by: Tejun Heo
21 Nov, 2011
4 commits
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* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (86 commits)
ipv4: fix redirect handling
ping: dont increment ICMP_MIB_INERRORS
sky2: fix hang in napi_disable
sky2: enforce minimum ring size
bonding: Don't allow mode change via sysfs with slaves present
f_phonet: fix page offset of first received fragment
stmmac: fix pm functions avoiding sleep on spinlock
stmmac: remove spin_lock in stmmac_ioctl.
stmmac: parameters auto-tuning through HW cap reg
stmmac: fix advertising 1000Base capabilties for non GMII iface
stmmac: use mdelay on timeout of sw reset
sky2: version 1.30
sky2: used fixed RSS key
sky2: reduce default Tx ring size
sky2: rename up/down functions
sky2: pci posting issues
sky2: fix hang on shutdown (and other irq issues)
r6040: fix check against MCRO_HASHEN bit in r6040_multicast_list
MAINTAINERS: change email address for shemminger
pch_gbe: Move #include of module.h
... -
* 'kvm-updates/3.2' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM guest: prevent tracing recursion with kvmclock
Revert "KVM: PPC: Add support for explicit HIOR setting"
KVM: VMX: Check for automatic switch msr table overflow
KVM: VMX: Add support for guest/host-only profiling
KVM: VMX: add support for switching of PERF_GLOBAL_CTRL
KVM: s390: announce SYNC_MMU
KVM: s390: Fix tprot locking
KVM: s390: handle SIGP sense running intercepts
KVM: s390: Fix RUNNING flag misinterpretation -
* 'fixes' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm:
ARM: wire up process_vm_writev and process_vm_readv syscalls
ARM: 7160/1: setup: avoid overflowing {elf,arch}_name from proc_info_list
ARM: 7158/1: add new MFP implement for NUC900
ARM: 7157/1: fix a building WARNING for nuc900
ARM: 7156/1: l2x0: fix compile error on !CONFIG_USE_OF
ARM: 7155/1: arch.h: Declare 'pt_regs' locally
ARM: 7154/1: mach-bcmring: fix build error in dma.c
ARM: 7153/1: mach-bcmring: fix build error in core.c
ARM: 7152/1: distclean: Remove generated .dtb files
ARM: 7150/1: Allow kernel unaligned accesses on ARMv6+ processors
ARM: 7149/1: spi/pl022: Enable clock in probe
Revert "ARM: 7098/1: kdump: copy kernel relocation code at the kexec prepare stage" -
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / Suspend: Fix bug in suspend statistics update
PM / Hibernate: Fix the early termination of test modes
PM / shmobile: Fix build of sh7372_pm_init() for CONFIG_PM unset
PM Sleep: Do not extend wakeup paths to devices with ignore_children set
PM / driver core: disable device's runtime PM during shutdown
PM / devfreq: correct Kconfig dependency
PM / devfreq: fix use after free in devfreq_remove_device
PM / shmobile: Avoid restoring the INTCS state during initialization
PM / devfreq: Remove compiler error after irq.h update
PM / QoS: Properly use the WARN() macro in dev_pm_qos_add_request()
PM / Clocks: Only disable enabled clocks in pm_clk_suspend()
ARM: mach-shmobile: sh7372 A3SP no_suspend_console fix
PM / shmobile: Don't skip debugging output in pd_power_up()
20 Nov, 2011
2 commits
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Prevent tracing of preempt_disable() in get_cpu_var() in
kvm_clock_read(). When CONFIG_DEBUG_PREEMPT is enabled,
preempt_disable/enable() are traced and this causes the function_graph
tracer to go into an infinite recursion. By open coding the
preempt_disable() around the get_cpu_var(), we can use the notrace
version which prevents preempt_disable/enable() from being traced and
prevents the recursion.Based on a similar patch for Xen from Jeremy Fitzhardinge.
Tested-by: Gleb Natapov
Acked-by: Steven Rostedt
Signed-off-by: Avi Kivity -
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (exynos4_tmu) Fix Kconfig dependency[ Merging code in-flight, just because I can. What timezone should I
use? - Linus ]
19 Nov, 2011
14 commits
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After commit 2a77c46de1e3dace73745015635ebbc648eca69c
(PM / Suspend: Add statistics debugfs file for suspend to RAM)
a missing pair of braces inside the state_store() function causes even
invalid arguments to suspend to be wrongly treated as failed suspend
attempts. Fix this.[rjw: Put the hash/subject of the buggy commit into the changelog.]
Signed-off-by: Srivatsa S. Bhat
Signed-off-by: Rafael J. Wysocki -
No longer at Citrix, still interested in Xen.
Signed-off-by: Jeremy Fitzhardinge
Cc: Jeremy Fitzhardinge
Signed-off-by: Linus Torvalds -
Dummy, non-zero definitions for HPAGE_MASK and HPAGE_SIZE were added in
51c6f666fceb ("mm: ZAP_BLOCK causes redundant work") to avoid a divide
by zero in generic kernel code.That code has since been removed, but probably should never have been
added in the first place: we don't want HPAGE_SIZE to act like PAGE_SIZE
for code that is working with hugepages, for example, when the
dependency on CONFIG_HUGETLB_PAGE has not been fulfilled.Because hugepage size can differ from architecture to architecture, each
is required to have their own definitions for both HPAGE_MASK and
HPAGE_SIZE. This is always done in arch/*/include/asm/page.h.So, just remove the dummy and dangerous definitions since they are no
longer needed and reveals the correct dependencies. Tested on
architectures using the definitions with allyesconfig: x86 (even with
thp), hppa, mips, powerpc, s390, sh3, sh4, sparc, and sparc64, and with
defconfig on ia64.Signed-off-by: David Rientjes
Signed-off-by: Linus Torvalds -
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
new helper: mount_subtree()
switch create_mnt_ns() to saner calling conventions, fix double mntput() in nfs
btrfs: fix double mntput() in mount_subvol() -
* 'for-linus' of git://oss.sgi.com/xfs/xfs:
MAINTAINERS: update XFS maintainer entry
xfs: use doalloc flag in xfs_qm_dqattach_one() -
* 'for-3.2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: Replace Paul Menage with Tejun Heo as cgroups maintainer -
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
random: Fix handing of arch_get_random_long in get_random_bytes()
x86: Call stop_machine_text_poke() on all CPUs
x86, ioapic: Only print ioapic debug information for IRQs belonging to an ioapic chip
x86/mrst: Avoid reporting wrong nmi status
x86/mrst: Add support for Penwell clock calibration
x86/apic: Allow use of lapic timer early calibration result
x86/apic: Do not clear nr_irqs_gsi if no legacy irqs
x86/platform: Add a wallclock_init func to x86_platforms ops
x86/mce: Make mce_chrdev_ops 'static const' -
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide:
cy82c693: fix PCI device selection
icside: DMA support fix
IDE: Don't powerdown Compaq Triflex IDE device on suspend
piix: ICH7 MWDMA1 errata -
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
sparc64: Patch sun4v code sequences properly on module load.
sparc: Kill custom io_remap_pfn_range().
sparc: Stash orig_i0 into %g6 instead of %g2
sparc: Fix handling of orig_i0 wrt. debugging when restarting syscalls.
sparc: sigutil: Include -
As is probably painfully obvious, I don't have time to be a cgroups
maintainer. Rather than have me continue to hope that I'll magically
find more spare time, instead Tejun has kindly agreed to take over the
role, along with Li Zefan.-tj: added cgroup tree URL to MAINTAINERS file
Signed-off-by: Paul Menage
Acked-by: Li Zefan
Signed-off-by: Tejun Heo
LKML-Reference: -
Commit 2aede851ddf08666f68ffc17be446420e9d2a056
(PM / Hibernate: Freeze kernel threads after preallocating memory)
postponed the freezing of kernel threads to after preallocating memory
for hibernation. But while doing that, the hibernation test TEST_FREEZER
and the test mode HIBERNATION_TESTPROC were not moved accordingly.As a result, when using these test modes, it only goes upto the freezing of
userspace and exits, when in fact it should go till the complete end of task
freezing stage, namely the freezing of kernel threads as well.So, move these points of exit to appropriate places so that freezing of
kernel threads is also tested while using these test harnesses.Signed-off-by: Srivatsa S. Bhat
Signed-off-by: Rafael J. Wysocki -
commit f39925dbde77 (ipv4: Cache learned redirect information in
inetpeer.) introduced a regression in ICMP redirect handling.It assumed ipv4_dst_check() would be called because all possible routes
were attached to the inetpeer we modify in ip_rt_redirect(), but thats
not true.commit 7cc9150ebe (route: fix ICMP redirect validation) tried to fix
this but solution was not complete. (It fixed only one route)So we must lookup existing routes (including different TOS values) and
call check_peer_redir() on them.Reported-by: Ivan Zahariev
Signed-off-by: Eric Dumazet
CC: Flavio Leitner
Signed-off-by: David S. Miller -
I will no longer be maintaining XFS for SGI. Ben Myers
(bpm@sgi.com) has agreed to be the primary maintainer
for XFS in my place. I will continue to be able to push
commits to the SGI XFS tree if required. As such I will
continue to be a designated XFS maintainer, but plan to
serve in more of a backup role.Signed-off-by: Alex Elder
Signed-off-by: Ben Myers -
ping module incorrectly increments ICMP_MIB_INERRORS if feeded with a
frame not belonging to its own sockets.RFC 2011 states that ICMP_MIB_INERRORS should count "the number of ICMP
messages which the entiry received but determined as having
ICMP-specific errors (bad ICMP checksums, bad length, etc.)."Signed-off-by: Eric Dumazet
CC: Vasiliy Kulikov
Acked-by: Flavio Leitner
Acked-by: Vasiliy Kulikov
Signed-off-by: David S. Miller
18 Nov, 2011
5 commits
-
…kernel/git/konrad/xen
* 'stable/for-linus-fixes-3.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
xen-gntalloc: signedness bug in add_grefs()
xen-gntalloc: integer overflow in gntalloc_ioctl_alloc()
xen-gntdev: integer overflow in gntdev_alloc_map()
xen:pvhvm: enable PVHVM VCPU placement when using more than 32 CPUs.
xen/balloon: Avoid OOM when requesting highmem
xen: Remove hanging references to CONFIG_XEN_PLATFORM_PCI
xen: map foreign pages for shared rings by updating the PTEs directly -
* 'for-linus' of git://git.kernel.dk/linux-block:
block: add missed trace_block_plug
paride: fix potential information leak in pg_read()
bio: change some signed vars to unsigned
block: avoid unnecessary plug list flush
cciss: auto engage SCSI mid layer at driver load time
loop: cleanup set_status interface
include/linux/bio.h: use a static inline function for bio_integrity_clone()
loop: prevent information leak after failed read
block: Always check length of all iov entries in blk_rq_map_user_iov()
The Windows driver .inf disables ASPM on all cciss devices. Do the same.
backing-dev: ensure wakeup_timer is deleted
block: Revert "[SCSI] genhd: add a new attribute "alias" in gendisk" -
* 'unicore32' of git://github.com/gxt/linux:
unicore32, exec: remove redundant set_fs(USER_DS)
unicore32: Fix typo 'PUV3_I2C'
unicore32: drop unused Kconfig symbols
rtc: rtc-puv3: Add __devinit and __devexit markers for probe and remove
arch/unicore32: do not use EXTRA_AFLAGS or EXTRA_CFLAGS
unicore32: fix build error for find bitops -
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc/signal32: Fix sigset_t conversion when copying to user
powerpc: Fix atomic_xxx_return barrier semantics
powerpc: Remove buggy 9-year-old test for binutils < 2.12.1
powerpc/book3e-64: Fix debug support for userspace
powerpc: Remove extraneous CONFIG_PPC_ADV_DEBUG_REGS define
powerpc: Revert show_regs() define for readability
powerpc/ps3: Fix SMP lockdep boot warning
powerpc/ps3: Fix lost SMP IPIs
powerpc: Add hvcall.h include to book3s_hv.c
powerpc/trace: Add a dummy stack frame for trace_hardirqs_off
powerpc: Copy down exception vectors after feature fixups
powerpc: panic if we can't instantiate RTAS
powerpc/4xx: Fix typos in kexec config dependencies
powerpc/fsl: MCU_MPC8349EMITX wants I2C built-in, modular won't do...
powerpc/fsl_udc_core: Fix dumb typo
carma-fpga: Missed switch from of_register_platform_driver()
powerpc: Fix build breakage in jump_label.c -
* 'for-linus' of git://git.selinuxproject.org/~jmorris/linux-security:
encrypted-keys: module build fixes
encrypted-keys: fix error return code
Smack: smackfs cipso seq read repair