Peter Zijlstra [Fri, 9 Oct 2015 16:36:29 +0000 (18:36 +0200)]
sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop()
The cpu_active() tests are not fundamentally part of stop_two_cpus(),
move then into the scheduler where they belong.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Peter Zijlstra [Fri, 9 Oct 2015 16:00:54 +0000 (18:00 +0200)]
sched: Start stopper early
Ensure the stopper thread is active 'early', because the load balancer
pretty much assumes that its available. And when 'online && active' the
load-balancer is fully available.
Not only the numa balancing stop_two_cpus() caller relies on it, but
also the self migration stuff does, and at CPU_ONLINE time the cpu
really is 'free' to run anything.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: heiko.carstens@de.ibm.com Link: http://lkml.kernel.org/r/20151009160054.GA10176@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Oleg Nesterov [Fri, 9 Oct 2015 16:00:51 +0000 (18:00 +0200)]
stop_machine: Kill cpu_stop_threads->setup() and cpu_stop_unpark()
Now that we always use stop_machine_unpark() to wake the stopper
threas up, we can kill ->setup() and fold cpu_stop_unpark() into
stop_machine_unpark().
And we do not need stopper->lock to set stopper->enabled = true.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: heiko.carstens@de.ibm.com Link: http://lkml.kernel.org/r/20151009160051.GA10169@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
1. Change smpboot_unpark_thread() to check ->selfparking, just
like smpboot_park_thread() does.
2. Introduce stop_machine_unpark() which sets ->enabled and calls
kthread_unpark().
3. Change smpboot_thread_call() and cpu_stop_init() to call
stop_machine_unpark() by hand.
This way:
- IMO the ->selfparking logic becomes more consistent.
- We can kill the smp_hotplug_thread->pre_unpark() method.
- We can easily unpark the stopper thread earlier. Say, we
can move stop_machine_unpark() from smpboot_thread_call()
to sched_cpu_active() as Peter suggests.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: heiko.carstens@de.ibm.com Link: http://lkml.kernel.org/r/20151009160049.GA10166@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Oleg Nesterov [Thu, 8 Oct 2015 14:51:34 +0000 (16:51 +0200)]
stop_machine: Introduce __cpu_stop_queue_work() and cpu_stop_queue_two_works()
Preparation to simplify the review of the next change. Add two simple
helpers, __cpu_stop_queue_work() and cpu_stop_queue_two_works() which
simply take a bit of code from their callers.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: heiko.carstens@de.ibm.com Link: http://lkml.kernel.org/r/20151008145134.GA18146@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Oleg Nesterov [Thu, 8 Oct 2015 14:51:31 +0000 (16:51 +0200)]
stop_machine: Ensure that a queued callback will be called before cpu_stop_park()
cpu_stop_queue_work() checks stopper->enabled before it queues the
work, but ->enabled == T can only guarantee cpu_stop_signal_done()
if we race with cpu_down().
This is not enough for stop_two_cpus() or stop_machine(), they will
deadlock if multi_cpu_stop() won't be called by one of the target
CPU's. stop_machine/stop_cpus are fine, they rely on stop_cpus_mutex.
But stop_two_cpus() has to check cpu_active() to avoid the same race
with hotplug, and this check is very unobvious and probably not even
correct if we race with cpu_up().
Change cpu_down() pass to clear ->enabled before cpu_stopper_thread()
flushes the pending ->works and returns with KTHREAD_SHOULD_PARK set.
Note also that smpboot_thread_call() calls cpu_stop_unpark() which
sets enabled == T at CPU_ONLINE stage, so this CPU can't go away until
cpu_stopper_thread() is called at least once. This all means that if
cpu_stop_queue_work() succeeds, we know that work->fn() will be called.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: heiko.carstens@de.ibm.com Link: http://lkml.kernel.org/r/20151008145131.GA18139@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Luca Abeni [Fri, 16 Oct 2015 08:06:21 +0000 (10:06 +0200)]
sched/deadline: Fix migration of SCHED_DEADLINE tasks
Commit:
9d5142624256 ("sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target")
broke select_task_rq_dl() and find_lock_later_rq(), because it introduced
a comparison between the local task's deadline and dl.earliest_dl.curr of
the remote queue.
However, if the remote runqueue does not contain any SCHED_DEADLINE
task its earliest_dl.curr is 0 (always smaller than the deadline of
the local task) and the remote runqueue is not selected for pushing.
As a result, if an application creates multiple SCHED_DEADLINE
threads, they will never be pushed to runqueues that do not already
contain SCHED_DEADLINE tasks.
This patch fixes the issue by checking if dl.dl_nr_running == 0.
Signed-off-by: Luca Abeni <luca.abeni@unitn.it> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Wanpeng Li <wanpeng.li@linux.intel.com> Fixes: 9d5142624256 ("sched/deadline: Reduce rq lock contention by eliminating locking of non-feasible target") Link: http://lkml.kernel.org/r/1444982781-15608-1-git-send-email-luca.abeni@unitn.it Signed-off-by: Ingo Molnar <mingo@kernel.org>
nohz: Revert "nohz: Set isolcpus when nohz_full is set"
This reverts:
8cb9764fc88b ("nohz: Set isolcpus when nohz_full is set")
We assumed that full-nohz users always want scheduler isolation on full
dynticks CPUs, therefore we included full-nohz CPUs on cpu_isolated_map.
This means that tasks run by default on CPUs outside the nohz_full range
unless their affinity is explicity overwritten.
This suits pure isolation workloads but when the machine is needed to
run common workloads, the available sets of CPUs to run common tasks
becomes reduced.
We reach an extreme case when CONFIG_NO_HZ_FULL_ALL is enabled as it
leaves only CPU 0 for non-isolation tasks, which makes people think that
their supercomputer regressed to 90's UP - which is true in a sense.
Some full-nohz users appear to be interested in running normal workloads
either before or after an isolation workload. Full-nohz isn't optimized
toward normal workloads but it's still better than UP performance.
We are reaching a limitation in kernel presets here. Lets revert this
cpu_isolated_map inclusion and let userspace do its own scheduler
isolation using cpusets or explicit affinity settings.
Reported-by: Ingo Molnar <mingo@kernel.org> Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dave Jones <davej@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E . McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Link: http://lkml.kernel.org/r/1444663283-30068-1-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Yuyang Du [Tue, 13 Oct 2015 01:18:22 +0000 (09:18 +0800)]
sched/fair: Fix overly small weight for interactive group entities
Commit:
9d89c257dfb9 ("sched/fair: Rewrite runnable load and utilization average tracking")
led to an overly small weight for interactive group entities. The bad case
can be easily reproduced when a number of CPU hogs compete for the CPUs
at the same time (thanks to Mike). This is largly because the task group's
load average tracking cross CPUs lags behind the real changes.
To fix this we accelerate the group share distribution process by using
the load.weight of the cfs_rq. This may increase the entire group's
share, but we have to do so to protect the (fragile) interactive
tasks, especially from CPU hogs.
Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com> Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Tested-by: Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by: Yuyang Du <yuyang.du@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1444699103-20272-1-git-send-email-yuyang.du@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
sched, tracing: Stop/start critical timings around the idle=poll idle loop
When using idle=poll, the preemptoff tracer is always showing
the idle task as the culprit for long latencies. That happens
because critical timings are not stopped before idle loop. This
patch stops critical timings before entering the idle loop,
starting it again after the idle loop.
This problem does not affect the irqsoff tracer because
interruptions are enabled before entering the idle loop.
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com> Reviewed-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/10fc3705874aef11dbe152a068b591a7be1899b4.1444314899.git.bristot@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Linus Torvalds [Sun, 11 Oct 2015 17:16:59 +0000 (10:16 -0700)]
Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Thomas Gleixner:
"Three trivial commits:
- Fix a kerneldoc regression
- Export handle_bad_irq to unbreak a driver in next
- Add an accessor for the of_node field so refactoring in next does
not depend on merge ordering"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqdomain: Add an accessor for the of_node field
genirq: Fix handle_bad_irq kerneldoc comment
genirq: Export handle_bad_irq
Linus Torvalds [Sun, 11 Oct 2015 17:02:30 +0000 (10:02 -0700)]
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"This is a set of three bug fixes, two of which are regressions from
recent updates (the 3ware one from 4.1 and the device handler fixes
from 4.2)"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
3w-9xxx: don't unmap bounce buffered commands
scsi_dh: Use the correct module name when loading device handler
libiscsi: Fix iscsi_check_transport_timeouts possible infinite loop
Linus Torvalds [Sat, 10 Oct 2015 18:17:45 +0000 (11:17 -0700)]
Merge tag 'usb-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
"Here are some small USB and PHY fixes and quirk updates for 4.3-rc5.
Nothing major here, full details in the shortlog, and all of these
have been in linux-next for a while"
* tag 'usb-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: Add device quirk for Logitech PTZ cameras
USB: chaoskey read offset bug
USB: Add reset-resume quirk for two Plantronics usb headphones.
usb: renesas_usbhs: Add support for R-Car H3
usb: renesas_usbhs: fix build warning if 64-bit architecture
usb: gadget: bdc: fix memory leak
phy: berlin-sata: Fix module autoload for OF platform driver
phy: rockchip-usb: power down phy when rockchip phy probe
phy: qcom-ufs: fix build error when the component is built as a module
Linus Torvalds [Sat, 10 Oct 2015 18:09:55 +0000 (11:09 -0700)]
Merge tag 'tty-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver fixes from Greg KH:
"Here are a few bug fixes for the tty core that resolve reported
issues, and some serial driver fixes as well (including the
much-reported imx driver problem)
All of these have been in linux-next with no reported problems"
* tag 'tty-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
drivers/tty: require read access for controlling terminal
serial: 8250: add uart_config entry for PORT_RT2880
tty: fix data race on tty_buffer.commit
tty: fix data race in tty_buffer_flush
tty: fix data race in flush_to_ldisc
tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.c
serial: atmel: fix error path of probe function
tty: don't leak cdev in tty_cdev_add()
Revert "serial: imx: remove unbalanced clk_prepare"
Linus Torvalds [Sat, 10 Oct 2015 18:03:31 +0000 (11:03 -0700)]
Merge tag 'staging-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging fixes from Greg KH:
"Here are two tiny staging tree fixes for 4.3-rc5.
One fixes the broken speakup subsystem as reported by a user, and the
other removes an entry in the MAINTAINERS file for a developer that
doesn't want to be listed anymore"
* tag 'staging-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: speakup: fix speakup-r regression
MAINTAINERS: Remove myself as nvec co-maintainer
Linus Torvalds [Sat, 10 Oct 2015 17:58:27 +0000 (10:58 -0700)]
Merge tag 'char-misc-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH:
"Here are some small fixes for some misc drivers that resolve some
reported issues. All of these have been linux-next for a while"
* tag 'char-misc-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
mcb: Fix error handling in mcb_pci_probe()
mei: hbm: fix error in state check logic
nvmem: sunxi: Check for memory allocation failure
nvmem: core: Fix memory leak in nvmem_cell_write
nvmem: core: Handle shift bits in-place if cell->nbits is non-zero
nvmem: core: fix the out-of-range leak in read/write()
Linus Torvalds [Sat, 10 Oct 2015 17:31:13 +0000 (10:31 -0700)]
Merge branch 'stable/for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb fixlet from Konrad Rzeszutek Wilk:
"Enable the SWIOTLB under 32-bit PAE kernels.
Nowadays most distros enable this due to CONFIG_HYPERVISOR|XEN=y which
select SWIOTLB. But for those that are not interested in
virtualization and wanting to use 32-bit PAE kernels and wanting to
have working DMA operations - this configures it for them"
* 'stable/for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
swiotlb: Enable it under x86 PAE
Trond Myklebust [Fri, 9 Oct 2015 17:44:34 +0000 (13:44 -0400)]
namei: results of d_is_negative() should be checked after dentry revalidation
Leandro Awa writes:
"After switching to version 4.1.6, our parallelized and distributed
workflows now fail consistently with errors of the form:
T34: ./regex.c:39:22: error: config.h: No such file or directory
From our 'git bisect' testing, the following commit appears to be the
possible cause of the behavior we've been seeing: commit 766c4cbfacd8"
Al Viro says:
"What happens is that 766c4cbfacd8 got the things subtly wrong.
We used to treat d_is_negative() after lookup_fast() as "fall with
ENOENT". That was wrong - checking ->d_flags outside of ->d_seq
protection is unreliable and failing with hard error on what should've
fallen back to non-RCU pathname resolution is a bug.
Unfortunately, we'd pulled the test too far up and ran afoul of
another kind of staleness. The dentry might have been absolutely
stable from the RCU point of view (and we might be on UP, etc), but
stale from the remote fs point of view. If ->d_revalidate() returns
"it's actually stale", dentry gets thrown away and the original code
wouldn't even have looked at its ->d_flags.
What we need is to check ->d_flags where 766c4cbfacd8 does (prior to
->d_seq validation) but only use the result in cases where we do not
discard this dentry outright"
Linus Torvalds [Sat, 10 Oct 2015 01:39:04 +0000 (18:39 -0700)]
Merge tag 'pm+acpi-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management and ACPI fixes from Rafael Wysocki:
"These are four fixes for bugs in the devfreq and cpufreq subsystems,
including two regression fixes (one for a recent regression and one
for a problem introduced in 4.2).
Specifics:
- Two fixes for cpufreq regressions, an acpi-cpufreq driver one
introduced during the 4.2 cycle when we started to preserve cpufreq
directories for offline CPUs and a general one introduced recently
(Srinivas Pandruvada).
- Two devfreq fixes, one for a double kfree() in an error code path
and one for a confusing sysfs-related failure (Geliang Tang, Tobias
Jakobi)"
* tag 'pm+acpi-4.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: prevent lockup on reading scaling_available_frequencies
cpufreq: acpi_cpufreq: prevent crash on reading freqdomain_cpus
PM / devfreq: fix double kfree
PM / devfreq: Fix governor_store()
Linus Torvalds [Fri, 9 Oct 2015 23:58:11 +0000 (16:58 -0700)]
Merge tag 'dm-4.3-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm
Pull dm fixes from Mike Snitzer:
"Three stable fixes:
- DM core AB-BA deadlock fix in the device destruction path (vs
device creation's DM table swap).
- DM raid fix to properly round up the region_size to the next
power-of-2.
- DM cache fix for a NULL pointer seen while switching from the
"cleaner" cache policy.
Two fixes for regressions introduced during the 4.3 merge:
- request-based DM error propagation regressed due to incorrect
changes introduced when adding the bi_error field to bio.
- DM snapshot fix to only support snapshots that overflow if the
client (e.g. lvm2) is prepared to deal with the associated
snapshot status interface change"
* tag 'dm-4.3-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
dm snapshot: add new persistent store option to support overflow
dm cache: fix NULL pointer when switching from cleaner policy
dm: fix request-based dm error reporting
dm raid: fix round up of default region size
dm: fix AB-BA deadlock in __dm_destroy()
Linus Torvalds [Fri, 9 Oct 2015 23:39:35 +0000 (16:39 -0700)]
Merge branch 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"These are small and assorted. Neil's is the oldest, I dropped the
ball thinking he was going to send it in"
* 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: support NFSv2 export
Btrfs: open_ctree: Fix possible memory leak
Btrfs: fix deadlock when finalizing block group creation
Btrfs: update fix for read corruption of compressed and shared extents
Btrfs: send, fix corner case for reference overwrite detection
Linus Torvalds [Fri, 9 Oct 2015 22:54:14 +0000 (15:54 -0700)]
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Arnd Bergmann:
"The fixes for this week include one small patch that was years in the
making and that finally fixes using all eight CPUs on exynos542x.
The rest are lots of minor changes for sunxi, imx, exynos and shmobile
- fixing the minimum voltage for Allwinner A20
- thermal boot issue on SMDK5250.
- invalid clock used for FIMD IOMMU.
- audio on Renesas r8a7790/r8a7791
- invalid clock used for FIMD IOMMU
- LEDs on exynos5422-odroidxu3-common
- usb pin control for imx-rex
- imx53: fix PMIC interrupt level
- a Makefile typo"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: dts: Fix wrong clock binding for sysmmu_fimd1_1 on exynos5420
ARM: dts: Fix bootup thermal issue on smdk5250
ARM: shmobile: r8a7791 dtsi: Add CPG/MSTP Clock Domain for sound
ARM: shmobile: r8a7790 dtsi: Add CPG/MSTP Clock Domain for sound
arm-cci500: Don't enable PMU driver by default
ARM: dts: fix usb pin control for imx-rex dts
ARM: imx53: qsrb: fix PMIC interrupt level
ARM: imx53: include IRQ dt-bindings header
ARM: dts: add suspend opp to exynos4412
ARM: dts: Fix LEDs on exynos5422-odroidxu3
ARM: EXYNOS: reset Little cores when cpu is up
ARM: dts: Fix Makefile target for sun4i-a10-itead-iteaduino-plus
ARM: dts: sunxi: Raise minimum CPU voltage for sun7i-a20 to meet SoC specifications
Mike Snitzer [Thu, 8 Oct 2015 22:05:41 +0000 (18:05 -0400)]
dm snapshot: add new persistent store option to support overflow
Commit 76c44f6d80 introduced the possibly for "Overflow" to be reported
by the snapshot device's status. Older userspace (e.g. lvm2) does not
handle the "Overflow" status response.
Fix this incompatibility by requiring newer userspace code, that can
cope with "Overflow", request the persistent store with overflow support
by using "PO" (Persistent with Overflow) for the snapshot store type.
Marc Zyngier [Fri, 9 Oct 2015 14:50:11 +0000 (15:50 +0100)]
irqdomain: Add an accessor for the of_node field
As we're about to remove the of_node field from the irqdomain
structure, introduce an accessor for it. Subsequent patches
will take care of the actual repainting.
Joe Thornber [Fri, 9 Oct 2015 13:03:38 +0000 (14:03 +0100)]
dm cache: fix NULL pointer when switching from cleaner policy
The cleaner policy doesn't make use of the per cache block hint space in
the metadata (unlike the other policies). When switching from the
cleaner policy to mq or smq a NULL pointer crash (in dm_tm_new_block)
was observed. The crash was caused by bugs in dm-cache-metadata.c
when trying to skip creation of the hint btree.
The minimal fix is to change hint size for the cleaner policy to 4 bytes
(only hint size supported).
Signed-off-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Cc: stable@vger.kernel.org
Mikulas Patocka [Thu, 1 Oct 2015 19:17:43 +0000 (15:17 -0400)]
crash in md-raid1 and md-raid10 due to incorrect list manipulation
The commit 55ce74d4bfe1b9444436264c637f39a152d1e5ac (md/raid1: ensure
device failure recorded before write request returns) is causing crash in
the LVM2 testsuite test shell/lvchange-raid.sh. For me the crash is 100%
reproducible.
The reason for the crash is that the newly added code in raid1d moves the
list from conf->bio_end_io_list to tmp, then tests if tmp is non-empty and
then incorrectly pops the bio from conf->bio_end_io_list (which is empty
because the list was alrady moved).
cpufreq: prevent lockup on reading scaling_available_frequencies
When scaling_available_frequencies is read on an offlined cpu, then
either lockup or junk values are displayed. This is caused by
freed freq_table, which policy is using.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: acpi_cpufreq: prevent crash on reading freqdomain_cpus
When freqdomain_cpus attribute is read from an offlined cpu, it will
cause crash. This change prevents calling cpufreq_show_cpus when
policy driver_data is NULL.
mmc: sdhci-of-at91: use SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST quirk
The Atmel sdhci device needs the
SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST quirk. Without it, the
internal clock could never stabilised when changing the sd clock
frequency.
The Atmel sdhci device needs a new quirk. sdhci_set_clock set the Clock
Control Register to 0 before computing the new value and writing it.
It disables the internal clock which causes a reset mecanism. If we
write the new value before this reset mecanism is done, it will prevent
the stabilisation of the internal clock, so a delay is needed. This
delay is about 2-3 cycles of the base clock. To be safe, a 1 ms delay is
used.
Nadav Haklai [Tue, 6 Oct 2015 01:22:36 +0000 (03:22 +0200)]
mmc: sdhci-pxav3: disable clock inversion for HS MMC cards
According to 'FE-2946959' erratum the clock inversion option is
needed to support slow frequencies when the card input hold time
requirement is high. This setting is not required for high speed
MMC and might cause timing violation.
Nadav Haklai [Tue, 6 Oct 2015 01:22:35 +0000 (03:22 +0200)]
mmc: sdhci-pxav3: remove broken clock base quirk for Armada 38x sdhci driver
shci-pxav3 driver is enabling by default the
SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN quirk. However this quirk is not
required for Armada 38x and leads to wrong clock setting in the divider.
Tony Lindgren [Wed, 7 Oct 2015 13:22:25 +0000 (06:22 -0700)]
mmc: host: omap_hsmmc: Fix MMC for omap3 legacy booting
Starting with commit 7d607f917008 ("mmc: host: omap_hsmmc: use
devm_regulator_get_optional() for vmmc") MMC on omap3 stopped working
for legacy booting.
This is because legacy booting sets up some of the resource in the
platform init code, and for optional regulators always seem to
return -EPROBE_DEFER for the legacy booting.
Let's fix the issue by checking for device tree based booting for
now. Then when omap3 boots in device tree only mode, this patch
can be just reverted.
Fixes: 7d607f917008 ("mmc: host: omap_hsmmc: use
devm_regulator_get_optional() for vmmc") Cc: Felipe Balbi <balbi@ti.com> Cc: Kishon Vijay Abraham I <kishon@ti.com> Cc: Nishanth Menon <nm@ti.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Without reverting this commit we get "unbalanced disables for pbias_mmc_omap4"
errors on omap4430. It seems that 4430 and 4460 behave in a different way for
the PBIAS regulator registers and until that has been debugged further we
cannot rely on the regulator status registers in hardare on 4430.
Fixes: 7d607f917008 ("mmc: host: omap_hsmmc: use
devm_regulator_get_optional() for vmmc") Cc: Felipe Balbi <balbi@ti.com> Cc: Kishon Vijay Abraham I <kishon@ti.com> Cc: Nishanth Menon <nm@ti.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Christian Melki [Mon, 5 Oct 2015 15:31:33 +0000 (17:31 +0200)]
swiotlb: Enable it under x86 PAE
Most distributions end up enabling SWIOTLB already with 32-bit
kernels due to the combination of CONFIG_HYPERVISOR_GUEST|CONFIG_XEN=y
as those end up requiring the SWIOTLB.
However for those that are not interested in virtualization and
run in 32-bit they will discover that: "32-bit PAE 4.2.0 kernel
(no IOMMU code) would hang when writing to my USB disk. The kernel
spews million(-ish messages per sec) to syslog, effectively
"hanging" userspace with my kernel.
Oct 2 14:33:06 voodoochild kernel: [ 223.287447] nommu_map_sg:
overflow 25dcac000+1024 of device mask ffffffff
Oct 2 14:33:06 voodoochild kernel: [ 223.287448] nommu_map_sg:
overflow 25dcac000+1024 of device mask ffffffff
Oct 2 14:33:06 voodoochild kernel: [ 223.287449] nommu_map_sg:
overflow 25dcac000+1024 of device mask ffffffff
... etc ..."
Enabling it makes the problem go away.
N.B. With a6dfa128ce5c414ab46b1d690f7a1b8decb8526d
"config: Enable NEED_DMA_MAP_STATE by default when SWIOTLB is selected"
we also have the important part of the SG macros enabled to make this
work properly - in case anybody wants to backport this patch.
Reported-and-Tested-by: Christian Melki <christian.melki@t2data.com> Signed-off-by: Christian Melki <christian.melki@t2data.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Takashi Iwai [Wed, 7 Oct 2015 18:11:21 +0000 (20:11 +0200)]
Merge tag 'asoc-fix-v4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Fixes for v4.3
Quite a few fixes here but they're all very small and driver specific,
none of them really stand out if you aren't using the relevant hardware
but they're all useful if you do happen to have an affected device.
3w controller don't dma map small single SGL entry commands but instead
bounce buffer them. Add a helper to identify these commands and don't
call scsi_dma_unmap for them.
Based on an earlier patch from James Bottomley.
Fixes: 118c85 ("3w-9xxx: fix command completion race") Reported-by: Tóth Attila <atoth@atoth.sote.hu> Tested-by: Tóth Attila <atoth@atoth.sote.hu> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Adam Radford <aradford@gmail.com> Signed-off-by: James Bottomley <JBottomley@Odin.com>
Linus Torvalds [Wed, 7 Oct 2015 17:17:46 +0000 (18:17 +0100)]
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon:
"This addresses a couple of issues found with RT, a broken initrd
message in the console log and a simple performance fix for some MMC
workloads.
Summary:
- A couple of locking fixes for RT kernels
- Avoid printing bogus initrd warnings when initrd isn't present
- Performance fix for random mmap file readahead
- Typo fix"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: replace read_lock to rcu lock in call_break_hook
arm64: Don't relocate non-existent initrd
arm64: convert patch_lock to raw lock
arm64: readahead: fault retry breaks mmap file read random detection
arm64: debug: Fix typo in debug-monitors.c
Linus Torvalds [Wed, 7 Oct 2015 17:05:09 +0000 (18:05 +0100)]
Merge tag 'fbdev-fixes-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux
Pull fbdev fixes from Tomi Valkeinen:
- fbdev: Minor fixes to broadsheetfb, fsl-diu-fb, mb862xxfb, tridentfb,
omapfb
- display-timing: Fix memory leak in error path
* tag 'fbdev-fixes-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux:
video: of: fix memory leak
fbdev: broadsheetfb: fix memory leak
OMAPDSS: panel-sony-acx565akm: Export OF module alias information
fbdev: omap2: connector-dvi: use of_get_i2c_adapter_by_node interface
tridentfb: Fix set_lwidth on TGUI9440 and CYBER9320
tridentfb: fix hang on Blade3D with CONFIG_CC_OPTIMIZE_FOR_SIZE
video: fbdev: mb862xx: Fix module autoload for OF platform driver
video: fbdev: fsl: Fix the sleep function for FSL DIU module
perf tools: Fix build break on powerpc due to sample_reg_masks
perf_regs.c does not get built on Powerpc as CONFIG_PERF_REGS is false.
So the weak definition for 'sample_regs_masks' doesn't get picked up.
Adding perf_regs.o to util/Build unconditionally, exposes a redefinition
error for 'perf_reg_value()' function (due to the static inline version
in util/perf_regs.h). So use #ifdef HAVE_PERF_REGS_SUPPORT' around that
function.
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Stephane Eranian <eranian@google.com> Cc: linuxppc-dev@ozlabs.org Link: http://lkml.kernel.org/r/20150930182836.GA27858@us.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linus Torvalds [Wed, 7 Oct 2015 13:15:49 +0000 (14:15 +0100)]
Merge tag 'regmap-fix-v4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
Pull regmap fixes from Mark Brown:
"A couple of fixes for the debugfs information on the register map,
fixing issues with very small reads potentially causing underflows and
wraparounds"
* tag 'regmap-fix-v4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: debugfs: Don't bother actually printing when calculating max length
regmap: debugfs: Ensure we don't underflow when printing access masks
Linus Torvalds [Wed, 7 Oct 2015 13:13:10 +0000 (14:13 +0100)]
Merge tag 'spi-fix-v4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi fixes from Mark Brown:
"A couple of very minor fixes, one for error handling in the Davinci
driver probe function and another making the Renesas sh-msiof DT
binding documentation correspond to what's actually implemented"
* tag 'spi-fix-v4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: sh-msiof: Match renesas,rx-fifo-size in DT bindings doc with driver
spi: davinci: fix handling platform_get_irq result
Linus Torvalds [Wed, 7 Oct 2015 13:11:47 +0000 (14:11 +0100)]
Merge tag 'regulator-fix-v4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator
Pull regulator fixes from Mark Brown:
"Two fixes here, one device specific fix for axp20x and a core fix for
cases where one regulator is supplying another which broke probe
deferral, substituting in a dummy regulator too aggressively"
* tag 'regulator-fix-v4.3-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
regulator: core: Handle probe deferral from DT when resolving supplies
regulator: axp20x: Fix enable bit indexes for DCDC4 and DCDC5
Linus Torvalds [Wed, 7 Oct 2015 08:52:42 +0000 (09:52 +0100)]
Merge branch 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile
Pull strscpy fixes from Chris Metcalf :
"This patch series fixes up a couple of architecture issues where
strscpy wasn't configured correctly (missing on h8300, duplicating
local and asm-generic copies on powerpc and tile).
It also adds a use of zero_bytemask() to the final store for strscpy
to avoid writing uninitialized data to the destination. However, to
make this work we had to add support for zero_bytemask() to the two
architectures that didn't have it (alpha and tile), because they were
providing their own local copies, but didn't provide the
zero_bytemask() that was previously only required when building with
CONFIG_DCACHE_WORD_ACCESS"
[ Side note: there is still no actual users of strscpy except for the
one preexisting use in arch/tile that predates the generic version.
So this is all about fixing the infrastructure so that we eventually
can start using it. - Linus ]
* 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
strscpy: zero any trailing garbage bytes in the destination
word-at-a-time.h: support zero_bytemask() on alpha and tile
word-at-a-time.h: fix some Kbuild files
Linus Torvalds [Wed, 7 Oct 2015 07:54:22 +0000 (08:54 +0100)]
Merge tag 'nfs-for-4.3-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
"Highlights include:
Bugfixes:
- Fix a use-after-free bug in the RPC/RDMA client
- Fix a write performance regression
- Fix up page writeback accounting
- Don't try to reclaim unused state owners
- Fix a NFSv4 nograce recovery hang
- reset states to use open_stateid when returning delegation
voluntarily
- Fix a tracepoint NULL-pointer dereference"
* tag 'nfs-for-4.3-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFS: Fix a tracepoint NULL-pointer dereference
nfs4: reset states to use open_stateid when returning delegation voluntarily
NFSv4: Fix a nograce recovery hang
NFSv4.1: nfs4_opendata_check_deleg needs to handle NFS4_OPEN_CLAIM_DELEG_CUR_FH
NFSv4: Don't try to reclaim unused state owners
NFS: Fix a write performance regression
NFS: Fix up page writeback accounting
xprtrdma: disconnect and flush cqs before freeing buffers
The commit itself does not appear to be buggy per se, but it is exposing
a bug in ext4 (and Ted thinks ext3 too, but we solved that by getting
rid of it). It's too late in the release cycle to really worry about
this, even if Dave Hansen has a patch that may actually fix the
underlying ext4 problem. We can (and should) revisit this for the next
release.
The problem is that moving the prefaulting later now exposes a special
case with partially successful writes that isn't handled correctly. And
the prefaulting likely isn't normally even that much of a performance
issue - it looks like at least one reason Dave saw this in his
performance tests is that he also ran them on Skylake that now supports
the new SMAP code, which makes the normally very cheap user space
prefaulting noticeably more expensive.
Bisected-and-acked-by: Ted Ts'o <tytso@mit.edu> Analyzed-and-acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Anna Schumaker [Mon, 5 Oct 2015 20:43:26 +0000 (16:43 -0400)]
NFS: Fix a tracepoint NULL-pointer dereference
Running xfstest generic/013 with the tracepoint nfs:nfs4_open_file
enabled produces a NULL-pointer dereference when calculating fileid and
filehandle of the opened file. Fix this by checking if state is NULL
before trying to use the inode pointer.
Reported-by: Olga Kornievskaia <aglo@umich.edu> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Chris Metcalf [Tue, 6 Oct 2015 16:37:41 +0000 (12:37 -0400)]
strscpy: zero any trailing garbage bytes in the destination
It's possible that the destination can be shadowed in userspace
(as, for example, the perf buffers are now). So we should take
care not to leak data that could be inspected by userspace.
Signed-off-by: Chris Metcalf <cmetcalf@ezchip.com>
call_break_hook is called in atomic context (hard irq disabled), so replace
the sleepable lock to rcu lock, replace relevant list operations to rcu
version and call synchronize_rcu() in unregister_break_hook().
And, replace write lock to spinlock in {un}register_break_hook.
Signed-off-by: Yang Shi <yang.shi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
Mark Rutland [Tue, 6 Oct 2015 17:24:37 +0000 (18:24 +0100)]
arm64: Don't relocate non-existent initrd
When booting a kernel without an initrd, the kernel reports that it
moves -1 bytes worth, having gone through the motions with initrd_start
equal to initrd_end:
Prevent this by bailing out early when the initrd size is zero (i.e. we
have no initrd), avoiding the confusing message and other associated
work.
Fixes: 1570f0d7ab425c1e ("arm64: support initrd outside kernel linear map") Cc: Mark Salter <msalter@redhat.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
Geliang Tang [Mon, 5 Oct 2015 13:26:05 +0000 (21:26 +0800)]
sched/core: Drop unlikely behind BUG_ON()
(1) For !CONFIG_BUG cases, the bug call is a no-op, so we couldn't care
less and the change is ok.
(2) PPC and MIPS, which HAVE_ARCH_BUG_ON, do not rely on branch predictions
as it seems to be pointless [1] and thus callers should not be trying to
push an optimization in the first place.
(3) For CONFIG_BUG and !HAVE_ARCH_BUG_ON cases, BUG_ON() contains an
unlikely compiler flag already.
Peter Zijlstra [Wed, 30 Sep 2015 15:44:13 +0000 (17:44 +0200)]
sched/core: Fix task and run queue sched_info::run_delay inconsistencies
Mike Meyer reported the following bug:
> During evaluation of some performance data, it was discovered thread
> and run queue run_delay accounting data was inconsistent with the other
> accounting data that was collected. Further investigation found under
> certain circumstances execution time was leaking into the task and
> run queue accounting of run_delay.
>
> Consider the following sequence:
>
> a. thread is running.
> b. thread moves beween cgroups, changes scheduling class or priority.
> c. thread sleeps OR
> d. thread involuntarily gives up cpu.
>
> a. implies:
>
> thread->sched_info.last_queued = 0
>
> a. and b. results in the following:
>
> 1. dequeue_task(rq, thread)
>
> sched_info_dequeued(rq, thread)
> delta = 0
>
> sched_info_reset_dequeued(thread)
> thread->sched_info.last_queued = 0
>
> thread->sched_info.run_delay += delta
>
> 2. enqueue_task(rq, thread)
>
> sched_info_queued(rq, thread)
>
> /* thread is still on cpu at this point. */
> thread->sched_info.last_queued = task_rq(thread)->clock;
>
> c. results in:
>
> dequeue_task(rq, thread)
>
> sched_info_dequeued(rq, thread)
>
> /* delta is execution time not run_delay. */
> delta = task_rq(thread)->clock - thread->sched_info.last_queued
>
> sched_info_reset_dequeued(thread)
> thread->sched_info.last_queued = 0
>
> thread->sched_info.run_delay += delta
>
> Since thread was running between enqueue_task(rq, thread) and
> dequeue_task(rq, thread), the delta above is really execution
> time and not run_delay.
>
> d. results in:
>
> __sched_info_switch(thread, next_thread)
>
> sched_info_depart(rq, thread)
>
> sched_info_queued(rq, thread)
>
> /* last_queued not updated due to being non-zero */
> return
>
> Since thread was running between enqueue_task(rq, thread) and
> __sched_info_switch(thread, next_thread), the execution time
> between enqueue_task(rq, thread) and
> __sched_info_switch(thread, next_thread) now will become
> associated with run_delay due to when last_queued was last updated.
>
This alternative patch solves the problem by not calling
sched_info_{de,}queued() in {de,en}queue_task(). Therefore the
sched_info state is preserved and things work as expected.
By inlining the {de,en}queue_task() functions the new condition
becomes (mostly) a compile-time constant and we'll not emit any new
branch instructions.
It even shrinks the code (due to inlining {en,de}queue_task()):
$ size defconfig-build/kernel/sched/core.o defconfig-build/kernel/sched/core.o.orig
text data bss dec hex filename
64019 23378 2344 89741 15e8d defconfig-build/kernel/sched/core.o
64149 23378 2344 89871 15f0f defconfig-build/kernel/sched/core.o.orig
Reported-by: Mike Meyer <Mike.Meyer@Teradata.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20150930154413.GO3604@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Peter Zijlstra [Mon, 28 Sep 2015 16:52:36 +0000 (18:52 +0200)]
sched/core: More notrace annotations
preempt_schedule_common() is marked notrace, but it does not use
_notrace() preempt_count functions and __schedule() is also not marked
notrace, which means that its perfectly possible to end up in the
tracer from preempt_schedule_common().
Steve says:
| Yep, there's some history to this. This was originally the issue that
| caused function tracing to go into infinite recursion. But now we have
| preempt_schedule_notrace(), which is used by the function tracer, and
| that function must not be traced till preemption is disabled.
|
| Now if function tracing is running and we take an interrupt when
| NEED_RESCHED is set, it calls
|
| preempt_schedule_common() (not traced)
|
| But then that calls preempt_disable() (traced)
|
| function tracer calls preempt_disable_notrace() followed by
| preempt_enable_notrace() which will see NEED_RESCHED set, and it will
| call preempt_schedule_notrace(), which stops the recursion, but
| still calls __schedule() here, and that means when we return, we call
| the __schedule() from preempt_schedule_common().
|
| That said, I prefer this patch. Preemption is disabled before calling
| __schedule(), and we get rid of a one round recursion with the
| scheduler.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
With the introduction of the context switch preempt_count invariant,
and the demise of PREEMPT_ACTIVE, its pointless to save/restore the
per-cpu preemption count, it must always be 2.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Peter Zijlstra [Mon, 28 Sep 2015 15:57:39 +0000 (17:57 +0200)]
sched/core: Robustify preemption leak checks
When we warn about a preempt_count leak; reset the preempt_count to
the known good value such that the problem does not ripple forward.
This is most important on x86 which has a per cpu preempt_count that is
not saved/restored (after this series). So if you schedule with an
invalid (!2*PREEMPT_DISABLE_OFFSET) preempt_count the next task is
messed up too.
Enforcing this invariant limits the borkage to just the one task.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Peter Zijlstra [Mon, 28 Sep 2015 16:06:56 +0000 (18:06 +0200)]
sched/core: Fix trace_sched_switch()
__trace_sched_switch_state() is the last remaining PREEMPT_ACTIVE
user, move trace_sched_switch() from prepare_task_switch() to
__schedule() and propagate the @preempt argument.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Peter Zijlstra [Mon, 28 Sep 2015 16:05:34 +0000 (18:05 +0200)]
sched/core: Add preempt argument to __schedule()
There is only a single PREEMPT_ACTIVE use in the regular __schedule()
path and that is to circumvent the task->state check. Since the code
setting PREEMPT_ACTIVE is the immediate caller of __schedule() we can
replace this with a function argument.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Peter Zijlstra [Mon, 28 Sep 2015 15:52:18 +0000 (17:52 +0200)]
sched/core: Create preempt_count invariant
Assuming units of PREEMPT_DISABLE_OFFSET for preempt_count() numbers.
Now that TASK_DEAD no longer results in preempt_count() == 3 during
scheduling, we will always call context_switch() with preempt_count()
== 2.
However, we don't always end up with preempt_count() == 2 in
finish_task_switch() because new tasks get created with
preempt_count() == 1.
Create FORK_PREEMPT_COUNT and set it to 2 and use that in the right
places. Note that we cannot use INIT_PREEMPT_COUNT as that serves
another purpose (boot).
After this, preempt_count() is invariant across the context switch,
with exception of PREEMPT_ACTIVE.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
we need PREEMPT_ACTIVE to avoid cond_resched() from working before
the scheduler is set up.
However, keeping preemption disabled should do the same thing
already, making the PREEMPT_ACTIVE part entirely redundant.
The only complication is !PREEMPT_COUNT kernels, where
PREEMPT_DISABLED ends up being 0. Instead we use an unconditional
PREEMPT_OFFSET to set preempt_count() even on !PREEMPT_COUNT
kernels.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
The argument being that the WMB will allow the load of A->state on CPU0
to cross over and observe CPU1's store of A->state, which will then
result in a double-drop and use-after-free.
Now the comment states (and this was true once upon a long time ago)
that we need to observe A->state while holding rq->lock because that
will order us against the wakeup; however the wakeup will not in fact
acquire (that) rq->lock; it takes A->pi_lock these days.
We can obviously fix this by upgrading the WMB to an MB, but that is
expensive, so we'd rather avoid that.
The alternative this patch takes is: smp_store_release(&A->on_cpu, 0),
which avoids the MB on some archs, but not important ones like ARM.
Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@vger.kernel.org> # v3.1+ Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Cc: manfred@colorfullife.com Cc: will.deacon@arm.com Fixes: e4a52bcb9a18 ("sched: Remove rq->lock from the first half of ttwu()") Link: http://lkml.kernel.org/r/20150929124509.GG3816@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
Junichi Nomura [Tue, 6 Oct 2015 04:19:54 +0000 (04:19 +0000)]
dm: fix request-based dm error reporting
end_clone_bio() is a endio callback for clone bio and should check
and save the clone's bi_error for error reporting. However, 4246a0b63bd8 ("block: add a bi_error field to struct bio") changed
the function to check the original bio's bi_error, which is 0.
Without this fix, clone's error is ignored and reported to the
original request as success. Thus data corruption will be observed.
Fixes: 4246a0b63bd8 ("block: add a bi_error field to struct bio") Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Linus Torvalds [Tue, 6 Oct 2015 14:05:02 +0000 (15:05 +0100)]
Merge tag 'for-linus-4.3b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen bug fixes from David Vrabel:
- Fix VM save performance regression with x86 PV guests
- Make kexec work in x86 PVHVM guests (if Xen has the soft-reset ABI)
- Other minor fixes.
* tag 'for-linus-4.3b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
x86/xen/p2m: hint at the last populated P2M entry
x86/xen: Do not clip xen_e820_map to xen_e820_map_entries when sanitizing map
x86/xen: Support kexec/kdump in HVM guests by doing a soft reset
xen/x86: Don't try to write syscall-related MSRs for PV guests
xen: use correct type for HYPERVISOR_memory_op()
projects / karo-tx-linux.git / log