Potential races between switch_mm() and TLB-flush or LDT-flush IPIs
could be very messy. AFAICT the code is currently okay, whether by
accident or by careful design, but enabling PCID will make it
considerably more complicated and will no longer be obviously safe.
Fix it with a big hammer: run switch_mm() with IRQs off.
To avoid a performance hit in the scheduler, we take advantage of
our knowledge that the scheduler already has IRQs disabled when it
calls switch_mm().
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/f19baf759693c9dcae64bbff76189db77cb13398.1461688545.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Chris Metcalf reported a that sched_can_stop_tick() sometimes fails to
re-enable the tick.
His observed problem is that rq->cfs.nr_running can be 1 even though
there are multiple runnable CFS tasks. This happens in the cgroup
case, in which case cfs.nr_running is the number of runnable entities
for that level.
If there is a single runnable cgroup (which can have an arbitrary
number of runnable child entries itself) rq->cfs.nr_running will be 1.
However, looking at that function I think there's more problems with it.
It seems to assume that if there's FIFO tasks, those will run. This is
incorrect. The FIFO task can have a lower prio than an RR task, in which
case the RR task will run.
So the whole fifo_nr_running test seems misplaced, it should go after
the rr_nr_running tests. That is, only if !rr_nr_running, can we use
fifo_nr_running like this.
Reported-by: Chris Metcalf <cmetcalf@mellanox.com>
Tested-by: Chris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Wanpeng Li <kernellwp@gmail.com>
Fixes: 76d92ac305 ("sched: Migrate sched to use new tick dependency mask model")
Link: http://lkml.kernel.org/r/20160421160315.GK24771@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull thermal fixes from Eduardo Valentin:
"Specifics in this pull request:
- Fixes in mediatek and OF thermal drivers
- Fixes in power_allocator governor
- More fixes of unsigned to int type change in thermal_core.c.
These change have been CI tested using KernelCI bot. \o/"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/evalenti/linux-soc-thermal:
thermal: fix Mediatek thermal controller build
thermal: consistently use int for trip temp
thermal: fix mtk_thermal build dependency
thermal: minor mtk_thermal.c cleanups
thermal: power_allocator: req_range multiplication should be a 64 bit type
thermal: of: add __init attribute
Pull asm-generic update from Arnd Bergmann:
"Here is one patch to wire up the preadv/pwritev system calls in the
generic system call table, which is required for all architectures
that were merged in the last few years, including arm64.
Usually these get merged along with the syscall implementation or one
of the architecture trees, but this time that did not happen.
Andre and Christoph both sent a version of this patch, I picked the
one I got first"
* tag 'asm-generic-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
generic syscalls: wire up preadv2 and pwritev2 syscalls
These new syscalls are implemented as generic code, so enable them for
architectures like arm64 which use the generic syscall table.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Pull x86 fixes from Ingo Molnar:
"Misc fixes: two EDAC driver fixes, a Xen crash fix, a HyperV log spam
fix and a documentation fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86 EDAC, sb_edac.c: Take account of channel hashing when needed
x86 EDAC, sb_edac.c: Repair damage introduced when "fixing" channel address
x86/mm/xen: Suppress hugetlbfs in PV guests
x86/doc: Correct limits in Documentation/x86/x86_64/mm.txt
x86/hyperv: Avoid reporting bogus NMI status for Gen2 instances
Pull perf, cpu hotplug and timer fixes from Ingo Molnar:
"perf:
- A single tooling fix for a user-triggerable segfault.
CPU hotplug:
- Fix a CPU hotplug corner case regression, introduced by the recent
hotplug rework
timers:
- Fix a boot hang in the ARM based Tango SoC clocksource driver"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf intel-pt: Fix segfault tracing transactions
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu/hotplug: Fix rollback during error-out in __cpu_disable()
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource/drivers/tango-xtal: Fix boot hang due to incorrect test
Pull locking fixes from Ingo Molnar:
"Misc fixes:
pvqspinlocks:
- an instrumentation fix
futexes:
- preempt-count vs pagefault_disable decouple corner case fix
- futex requeue plist race window fix
- futex UNLOCK_PI transaction fix for a corner case"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
asm-generic/futex: Re-enable preemption in futex_atomic_cmpxchg_inatomic()
futex: Acknowledge a new waiter in counter before plist
futex: Handle unlock_pi race gracefully
locking/pvqspinlock: Fix division by zero in qstat_read()
Pull irq fixes from Ingo Molnar:
"A core irq affinity masks related fix and a MIPS irqchip driver fix"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/mips-gic: Don't overrun pcpu_masks array
genirq: Dont allow affinity mask to be updated on IPIs
Pull objtool fixes from Ingo Molnar:
"A handful of objtool fixes: two improvements to how warnings are
printed plus a false positive warning fix, and build environment fix"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Fix Makefile to properly see if libelf is supported
objtool: Detect falling through to the next function
objtool: Add workaround for GCC switch jump table bug
Pull USB / PHY driver fixes from Greg KH:
"Here are two small sets of patches, both from subsystem trees, USB
gadget and PHY drivers.
Full details are in the shortlog, and they have all been in linux-next
for a while (before I merged them to the USB tree)"
* tag 'usb-4.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: gadget: f_fs: Fix use-after-free
usb: dwc3: gadget: Fix suspend/resume during device mode
usb: dwc3: fix memory leak of dwc->regset
usb: dwc3: core: fix PHY handling during suspend
usb: dwc3: omap: fix up error path on probe()
usb: gadget: composite: Clear reserved fields of SSP Dev Cap
phy: rockchip-emmc: adapt binding to specifiy register offset and length
phy: rockchip-emmc: should be a child device of the GRF
phy: rockchip-dp: should be a child device of the GRF
Pull serial fixes from Greg KH:
"Here are 3 serial driver fixes for issues that have been reported.
Two are reverts, fixing problems that were in the big TTY/Serial
driver merge in 4.6-rc1, and the last one is a simple bugfix for a
regression that showed up in 4.6-rc1 as well.
All have been in linux-next with no reported issues"
* tag 'tty-4.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
Revert "serial: 8250: Add hardware dependency to RT288X option"
tty/serial/8250: fix RS485 half-duplex RX
Revert "serial-uartlite: Constify uartlite_be/uartlite_le"
I got a minus(very big) dl_b->total_bw during my deadline tests.
# grep dl /proc/sched_debug
dl_rq[0]:
.dl_nr_running : 0
.dl_bw->bw : 996147
.dl_bw->total_bw : -222297900
Something unusual must have happened.
After some digging, I finally noticed that when changing a deadline
task to normal(cfs), and changing it back to deadline immediately,
after it died, we will got the wrong dl_bw->total_bw.
The root cause is in dl_overflow(), it has:
if (new_bw == p->dl.dl_bw)
return 0;
1) When a deadline task is changed to !deadline task, it will start
dl timer in switched_from_dl(), and retain previous deadline parameter
till the timer expires.
2) If we change it back to deadline with the same bandwidth parameter
before the timer expires, as it keeps the old bandwidth although it
is not a deadline task. dl_overflow() simply returns success without
updating the right data, and got the wrong dl_bw->total_bw.
The solution is simple, if @p is not deadline, don't return.
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juri Lelli <juri.lelli@arm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1460636368-1993-1-git-send-email-xlpang@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Ticks can happen while the CPU is in dynticks-idle or dynticks-singletask
mode. In fact "nohz" or "dynticks" only mean that we exit the periodic
mode and we try to minimize the ticks as much as possible. The nohz
subsystem uses a confusing terminology with the internal state
"ts->tick_stopped" which is also available through its public interface
with tick_nohz_tick_stopped(). This is a misnomer as the tick is instead
reduced with the best effort rather than stopped. In the best case the
tick can indeed be actually stopped but there is no guarantee about that.
If a timer needs to fire one second later, a tick will fire while the
CPU is in nohz mode and this is a very common scenario.
Now this confusion happens to be a problem with CPU load updates:
cpu_load_update_active() doesn't handle nohz ticks correctly because it
assumes that ticks are completely stopped in nohz mode and that
cpu_load_update_active() can't be called in dynticks mode. When that
happens, the whole previous tickless load is ignored and the function
just records the load for the current tick, ignoring potentially long
idle periods behind.
In order to solve this, we could account the current load for the
previous nohz time but there is a risk that we account the load of a
task that got freshly enqueued for the whole nohz period.
So instead, lets record the dynticks load on nohz frame entry so we know
what to record in case of nohz ticks, then use this record to account
the tickless load on nohz ticks and nohz frame end.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
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: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1460555812-25375-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When asymmetric packing is set in the sched_domain and target CPU is
busy, update_sd_pick_busiest() may not select the busiest runqueue.
When target CPU is busy, find_busiest_group() will ignore checks for
asym packing and may continue to load balance using the currently
selected not-the-busiest runqueue as source runqueue.
Selecting the busiest runqueue as source when the target CPU is busy,
should result in achieving much better load balance.
Also when target CPU is not busy and asymmetric packing is set in sd,
select higher CPU as source CPU for load balancing.
While doing this change, move the check to see if target CPU is busy
into check_asym_packing().
The extent of performance benefit from this change decreases with the
increasing load. However there is benefit in undercommit as well as
overcommit conditions.
1. Record per second ebizzy (32 threads) on a 64 CPU power 7 box. (5 iterations)
4.6.0-rc2
Testcase: Min Max Avg StdDev
ebizzy: 5223767.00 10368236.00 7946971.00 1753094.76
4.6.0-rc2+asym-changes
Testcase: Min Max Avg StdDev %Change
ebizzy: 8617191.00 13872356.00 11383980.00 1783400.89 +24.78%
2. Record per second ebizzy (64 threads) on a 64 CPU power 7 box. (5 iterations)
4.6.0-rc2
Testcase: Min Max Avg StdDev
ebizzy: 6497666.00 18399783.00 10818093.20 4051452.08
4.6.0-rc2+asym-changes
Testcase: Min Max Avg StdDev %Change
ebizzy: 7567365.00 19456937.00 11674063.60 4295407.48 +4.40%
3. Record per second ebizzy (128 threads) on a 64 CPU power 7 box. (5 iterations)
4.6.0-rc2
Testcase: Min Max Avg StdDev
ebizzy: 37073983.00 40341911.00 38776241.80 1259766.82
4.6.0-rc2+asym-changes
Testcase: Min Max Avg StdDev %Change
ebizzy: 38030399.00 41333378.00 39827404.40 1255001.86 +2.54%
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Gautham R Shenoy <ego@linux.vnet.ibm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1459948660-16073-1-git-send-email-srikar@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull pin control fixes from Linus Walleij:
"Some pin control driver fixes came in. One headed for stable and the
other two are just ordinary merge window fixes.
- Make the i.MX driver select REGMAP as a dependency
- Fix up the Mediatek debounce time unit
- Fix a real hairy ffs vs __ffs issue in the Single pinctrl driver"
* tag 'pinctrl-v4.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: single: Fix pcs_parse_bits_in_pinctrl_entry to use __ffs than ffs
pinctrl: mediatek: correct debounce time unit in mtk_gpio_set_debounce
pinctrl: imx: Kconfig: PINCTRL_IMX select REGMAP
Pull arm64 fixes from Catalin Marinas:
- Cache invalidation fix for early CPU boot status update (incorrect
cacheline)
- of_put_node() missing in the spin_table code
- EL1/El2 early init inconsistency when Virtualisation Host Extensions
are present
- RCU warning fix in the arm_pmu.c driver
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: Fix EL1/EL2 early init inconsistencies with VHE
drivers/perf: arm-pmu: fix RCU usage on pmu resume from low-power
arm64: spin-table: add missing of_node_put()
arm64: fix invalidation of wrong __early_cpu_boot_status cacheline
Pull powerpc fixes from Michael Ellerman:
"Three powerpc cpu feature fixes from Anton Blanchard:
- scan_features() updated incorrect bits for REAL_LE
- update cpu_user_features2 in scan_features()
- update TM user feature bits in scan_features()"
* tag 'powerpc-4.6-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc: Update TM user feature bits in scan_features()
powerpc: Update cpu_user_features2 in scan_features()
powerpc: scan_features() updates incorrect bits for REAL_LE
Pull IOMMU fixes from Joerg Roedel:
"The fixes include:
- Two patches to revert the use of default domains in the ARM SMMU
driver. Enabling this caused regressions which need more thorough
fixing. So the regressions are fixed for now by disabling the use
of default domains.
- A fix for a v4.4 regression in the AMD IOMMU driver which broke
devices behind invisible PCIe-to-PCI bridges with IOMMU enabled"
* tag 'iommu-fixes-v4.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
iommu/arm-smmu: Don't allocate resources for bypass domains
iommu/arm-smmu: Fix stream-match conflict with IOMMU_DOMAIN_DMA
iommu/amd: Fix checking of pci dma aliases
Pull drm fixes from Dave Airlie:
"i915, nouveau and amdgpu/radeon fixes in this:
nouveau:
Two fixes, one for a regression with dithering and one for a bug
hit by the userspace drivers.
i915:
A few fixes, mostly things heading for stable, two important
skylake GT3/4 hangs.
radeon/amdgpu:
Some audio, suspend/resume and some runtime PM fixes, along with
two patches to harden the userptr ABI a bit"
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (24 commits)
drm: Loongson-3 doesn't fully support wc memory
drm/nouveau/gr/gf100: select a stream master to fixup tfb offset queries
amdgpu/uvd: add uvd fw version for amdgpu
drm/amdgpu: forbid mapping of userptr bo through radeon device file
drm/radeon: forbid mapping of userptr bo through radeon device file
drm/amdgpu: bump the afmt limit for CZ, ST, Polaris
drm/amdgpu: use defines for CRTCs and AMFT blocks
drm/dp/mst: Validate port in drm_dp_payload_send_msg()
drm/nouveau/kms: fix setting of default values for dithering properties
drm/radeon: print a message if ATPX dGPU power control is missing
Revert "drm/radeon: disable runtime pm on PX laptops without dGPU power control"
drm/amdgpu/acp: fix resume on CZ systems with AZ audio
drm/radeon: add a quirk for a XFX R9 270X
drm/radeon: print pci revision as well as pci ids on driver load
drm/i915: Use fw_domains_put_with_fifo() on HSW
drm/i915: Force ringbuffers to not be at offset 0
drm/i915: Adjust size of PIPE_CONTROL used for gen8 render seqno write
drm/i915/skl: Fix spurious gpu hang with gt3/gt4 revs
drm/i915/skl: Fix rc6 based gpu/system hang
drm/i915/userptr: Hold mmref whilst calling get-user-pages
...
Pull sound fixes from Takashi Iwai:
"Again a relatively calm week without surprise: most of fixes are about
HD-audio, including fixes for Cirrus codec regression and a race over
regmap access. Although both change are slightly unintuitive, the
risk of further breakage is quite low, I hope.
Other than that, all the rest are trivial"
* tag 'sound-4.6-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: hda - Fix possible race on regmap bypass flip
ALSA: pcxhr: Fix missing mutex unlock
ALSA: hda - add PCI ID for Intel Broxton-T
ALSA: hda - Keep powering up ADCs on Cirrus codecs
ALSA: hda/realtek - Add ALC3234 headset mode for Optiplex 9020m
ALSA - hda: hdmi check NULL pointer in hdmi_set_chmap
ALSA: hda - Don't trust the reported actual power state
Felipe writes:
usb: fixes for v4.6-rc5
No more major fixes left. Out of the 6 fixes we have
here, 4 are on dwc3.
The most important is the memory leak fix in
dwc3/debugfs.c. We also have a fix for PHY handling
in suspend/resume and a fix for dwc3-omap's error
handling.
Suspend/resume also had the potential to trigger a
NULL pointer dereference on dwc3; that's also fixed
now.
Our good ol' ffs function gets a use-after-free fix
while the generic composite.c layer has a robustness
fix by making sure reserved fields of a possible SSP
device capability descriptor is cleared to 0.
Huge pages are not normally available to PV guests. Not suppressing
hugetlbfs use results in an endless loop of page faults when user mode
code tries to access a hugetlbfs mapped area (since the hypervisor
denies such PTEs to be created, but error indications can't be
propagated out of xen_set_pte_at(), just like for various of its
siblings), and - once killed in an oops like this:
kernel BUG at .../fs/hugetlbfs/inode.c:428!
invalid opcode: 0000 [#1] SMP
...
RIP: e030:[<ffffffff811c333b>] [<ffffffff811c333b>] remove_inode_hugepages+0x25b/0x320
...
Call Trace:
[<ffffffff811c3415>] hugetlbfs_evict_inode+0x15/0x40
[<ffffffff81167b3d>] evict+0xbd/0x1b0
[<ffffffff8116514a>] __dentry_kill+0x19a/0x1f0
[<ffffffff81165b0e>] dput+0x1fe/0x220
[<ffffffff81150535>] __fput+0x155/0x200
[<ffffffff81079fc0>] task_work_run+0x60/0xa0
[<ffffffff81063510>] do_exit+0x160/0x400
[<ffffffff810637eb>] do_group_exit+0x3b/0xa0
[<ffffffff8106e8bd>] get_signal+0x1ed/0x470
[<ffffffff8100f854>] do_signal+0x14/0x110
[<ffffffff810030e9>] prepare_exit_to_usermode+0xe9/0xf0
[<ffffffff814178a5>] retint_user+0x8/0x13
This is CVE-2016-3961 / XSA-174.
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <JGross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: stable@vger.kernel.org
Cc: xen-devel <xen-devel@lists.xenproject.org>
Link: http://lkml.kernel.org/r/57188ED802000078000E431C@prv-mh.provo.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The recent introduction of the hotplug thread which invokes the callbacks on
the plugged cpu, cased the following regression:
If takedown_cpu() fails, then we run into several issues:
1) The rollback of the target cpu states is not invoked. That leaves the smp
threads and the hotplug thread in disabled state.
2) notify_online() is executed due to a missing skip_onerr flag. That causes
that both CPU_DOWN_FAILED and CPU_ONLINE notifications are invoked which
confuses quite some notifiers.
3) The CPU_DOWN_FAILED notification is not invoked on the target CPU. That's
not an issue per se, but it is inconsistent and in consequence blocks the
patches which rely on these states being invoked on the target CPU and not
on the controlling cpu. It also does not preserve the strict call order on
rollback which is problematic for the ongoing state machine conversion as
well.
To fix this we add a rollback flag to the remote callback machinery and invoke
the rollback including the CPU_DOWN_FAILED notification on the remote
cpu. Further mark the notify online state with 'skip_onerr' so we don't get a
double invokation.
This workaround will go away once we moved the unplug invocation to the target
cpu itself.
[ tglx: Massaged changelog and moved the CPU_DOWN_FAILED notifiaction to the
target cpu ]
Fixes: 4cb28ced23 ("cpu/hotplug: Create hotplug threads")
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-s390@vger.kernel.org
Cc: rt@linutronix.de
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Link: http://lkml.kernel.org/r/20160408124015.GA21960@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
