A kthread doing set_freezable*() may race with on-going PM freeze and
the freezer might think all tasks are frozen while the new freezable
kthread is merrily proceeding to execute code paths which aren't
supposed to be executing during PM freeze.
Reimplement set_freezable[_with_signal]() using __set_freezable() such
that freezable PF flags are modified under freezer_lock and
try_to_freeze() is called afterwards. This eliminates race condition
against freezing.
Note: Separated out from larger patch to resolve fix order dependency
Oleg pointed out.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
should_send_signal() is only used in freezer.c. Exporting them only
increases chance of abuse. Open code the two users and remove it.
Update frozen() to return bool.
Signed-off-by: Tejun Heo <tj@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 <tj@kernel.org>
Acked-by: Paul Menage <paul@paulmenage.org> (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 <tj@kernel.org>
Acked-by: Paul Menage <paul@paulmenage.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Oleg Nesterov <oleg@redhat.com>
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 <tj@kernel.org>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
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 <tj@kernel.org>
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 <tj@kernel.org>
Cc: Paul Menage <menage@google.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
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 <tj@kernel.org>
Acked-by: Henrique de Moraes Holschuh <ibm-acpi@hmh.eng.br>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Oleg Nesterov <oleg@redhat.com>
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 <tj@kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Christoph Hellwig <hch@infradead.org>
* 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
...
* '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()
Dummy, non-zero definitions for HPAGE_MASK and HPAGE_SIZE were added in
51c6f666fc ("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 <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* '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()
* '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"
Commit 4ca46ff3e0 (PM / Sleep: Mark
devices involved in wakeup signaling during suspend) introduced
the power.wakeup_path field in struct dev_pm_info to mark devices
whose children are enabled to wake up the system from sleep states,
so that power domains containing the parents that provide their
children with wakeup power and/or relay their wakeup signals are not
turned off. Unfortunately, that introduced a PM regression on SH7372
whose power consumption in the system "memory sleep" state increased
as a result of it, because it prevented the power domain containing
the I2C controller from being turned off when some children of that
controller were enabled to wake up the system, although the
controller was not necessary for them to signal wakeup.
To fix this issue use the observation that devices whose
power.ignore_children flag is set for runtime PM should be treated
analogously during system suspend. Namely, they shouldn't be
included in wakeup paths going through their children. Since the
SH7372 I2C controller's power.ignore_children flag is set, doing so
will restore the previous behavior of that SOC.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit a15bd354f0.
It exceeded the padding on the SREGS struct, rendering the ABI
backwards-incompatible.
Conflicts:
arch/powerpc/kvm/powerpc.c
include/linux/kvm.h
Signed-off-by: Avi Kivity <avi@redhat.com>
takes vfsmount and relative path, does lookup within that vfsmount
(possibly triggering automounts) and returns the result as root
of subtree suitable for return by ->mount() (i.e. a reference to
dentry and an active reference to its superblock grabbed, superblock
locked exclusive).
btrfs and nfs switched to it instead of open-coding the sucker.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In 5fbdc10395 the XEN_PLATFORM_PCI config
option was removed, but references in header files remained. Clean up
those references.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
When mapping a foreign page with xenbus_map_ring_valloc() with the
GNTTABOP_map_grant_ref hypercall, set the GNTMAP_contains_pte flag and
pass a pointer to the PTE (in init_mm).
After the page is mapped, the usual fault mechanism can be used to
update additional MMs. This allows the vmalloc_sync_all() to be
removed from alloc_vm_area().
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
[v1: Squashed fix by Michal for no-mmu case]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
This is just a cleanup patch to silence a static checker warning.
The problem is that we cap "nr_iovecs" so it can't be larger than
"UIO_MAXIOV" but we don't check for negative values. It turns out this is
prevented at other layers, but logically it doesn't make sense to have
negative nr_iovecs so making it unsigned is nicer.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When CONFIG_BLK_DEV_INTEGRITY is not set, we get these warnings:
drivers/md/dm.c: In function 'split_bvec':
drivers/md/dm.c:1061:3: warning: statement with no effect
drivers/md/dm.c: In function 'clone_bio':
drivers/md/dm.c:1088:3: warning: statement with no effect
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
* 'fixes' of git://git.linaro.org/people/triad/linux-pinctrl:
pinctrl: hide subsystem from the populace
pinctrl: fix "warning: 'struct pinctrl_dev' declared inside parameter list"
* 'rmobile-fixes-for-linus' of git://github.com/pmundt/linux-sh:
ARM: mach-shmobile: cpuidle single/global and last_state fixes
ARM: mach-shmobile: move helper macro PORTCR to sh_pfc.h
ARM: mach-shmobile: move helper macro PORT_xx to sh_pfc.h
ARM: mach-shmobile: move helper macro PORT_DATA_xx to sh_pfc.h
ARM: mach-shmobile: ap4evb: remove white space from end of line
ARM: mach-shmobile: clock-sh7372: remove un-necessary index
ARM: mach-shmobile: kota2: add comment out separator
ARM: mach-shmobile: sh73a0: add MMC data pin pull-up
commit 3ceca74966 added a TOS attribute.
Unfortunately TOS and TCLASS are both present in a dual-stack v6 socket,
furthermore they can have different values. As such one cannot in a
sane way expose both through a single attribute.
Signed-off-by: Maciej Żenczyowski <maze@google.com>
CC: Murali Raja <muralira@google.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
CC: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: usb-audio: Use kmemdup rather than duplicating its implementation
ALSA: hda - Re-enable the check NO_PRESENCE misc bit
ALSA: vmaster - Free slave-links when freeing the master element
ALSA: hda - Don't add elements of other codecs to vmaster slave
ALSA: intel8x0: improve virtual environment detection
ALSA: intel8x0: move virtual environment detection code into one place
ALSA: snd_usb_audio: add Logitech HD Webcam c510 to quirk-384
ALSA: hda - fix internal mic on Dell Vostro 3500 laptop
ALSA: HDA: Remove quirk for Toshiba T110
ALSA: usb-audio - Fix the missing volume quirks at delayed init
ALSA: hda - Mute unused capture sources for Realtek codecs
ALSA: intel8x0: Improve comments for VM optimization
ASoC: Ensure we get an impedence reported for WM8958 jack detect
ASoC: Don't use wm8994->control_data when requesting IRQs
ASoC: Don't use wm8994->control_data in wm8994_readable_register()
ASoC: Update git repository URL
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (42 commits)
drm/radeon/kms/pm: switch to dynamically allocating clock mode array
drm/radeon/kms: optimize r600_pm_profile_init
drm/radeon/kms/pm: add a proper pm profile init function for fusion
drm/radeon/kms: remove extraneous calls to radeon_pm_compute_clocks()
drm/exynos: added padding to be 64-bit align.
drm: fix kconfig unmet dependency warning
drm: add some comments to drm_wait_vblank and drm_queue_vblank_event
drm/radeon/benchmark: signedness bug in radeon_benchmark_move()
drm: do not sleep on vblank while holding a mutex
MAINTAINERS: exynos: Add EXYNOS DRM maintainer entry
drm: try to restore previous CRTC config if mode set fails
drm/radeon/kms: make an aux failure debug only
drm: drop select of SLOW_WORK
drm: serialize access to list of debugfs files
drm/radeon/kms: fix use of vram scratch page on evergreen/ni
drm/radeon: Make sure CS mutex is held across GPU reset.
drm: Ensure string is null terminated.
vmwgfx: Only allow 64x64 cursors
vmwgfx: Initialize clip rect loop correctly in surface dirty
vmwgfx: Close screen object system
...
Nouveau, when configured with debugfs, creates debugfs files for every
channel, so structure holding list of files needs to be protected from
simultaneous changes by multiple threads.
Without this patch it's possible to hit kernel oops in
drm_debugfs_remove_files just by running a couple of xterms with
looped glxinfo.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This patch moves PORT_xx helper macro to sh_pfc.h,
and it expects CPU_ALL_PORT() macro for each CPU
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This patch move PORT_DATA_xx helper macro to sh_pfc.h.
and pfc-sh7372.c used it
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Now that all of the named string association with clocks has been
migrated to clkdev lookups there's no meaningful named topology that can
be constructed for a debugfs tree view. Get rid of the left over bits,
and shrink struct clk a bit in the process.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This reverts commit a72c5e5eb7.
The commit introduced alias for block devices which is intended to be
used during logging although actual usage hasn't been committed yet.
This approach adds very limited benefit (raw log might be easier to
follow) which can be trivially implemented in userland but has a lot
of problems.
It is much worse than netif renames because it doesn't rename the
actual device but just adds conveninence name which isn't used
universally or enforced. Everything internal including device lookup
and sysfs still uses the internal name and nothing prevents two
devices from using conflicting alias - ie. sda can have sdb as its
alias.
This has been nacked by people working on device driver core, block
layer and kernel-userland interface and shouldn't have been
upstreamed. Revert it.
http://thread.gmane.org/gmane.linux.kernel/1155104http://thread.gmane.org/gmane.linux.scsi/68632http://thread.gmane.org/gmane.linux.scsi/69776
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Nao Nishijima <nao.nishijima.xt@hitachi.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
when pinctl subsystem is not selected, when compiling drivers including
the include/linux/pinctrl/pinctrl.h, we will get the warning as below:
In file included from include/linux/pinctrl/pinmux.h:17,
from drivers/tty/serial/sirfsoc_uart.c:25:
include/linux/pinctrl/pinctrl.h:126: warning: 'struct pinctrl_dev'
declared inside parameter list
include/linux/pinctrl/pinctrl.h:126: warning: its scope is only this
definition or declaration, which is probably not what you want
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Two new struct members were not documented, fix that.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Fix below build warning:
CC arch/arm/mach-omap2/hwspinlock.o
In file included from arch/arm/mach-omap2/hwspinlock.c:22:
include/linux/hwspinlock.h: In function '__hwspin_unlock':
include/linux/hwspinlock.h:121: warning: 'return' with a value, in function returning void
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
The "private_date" field in struct devfreq_dev_status almost certainly
wants to be "private_data"; since there are no in-tree users of this
functionality, now seems like an easy time to make the fix.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
