Pull irq fixes from Thomas Gleixner:
"Another four fixlets to tame the ARM orion irq chip"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip: orion: Fix getting generic chip pointer.
irqchip: orion: clear stale interrupts in irq_startup
irqchip: orion: use handle_edge_irq on bridge irqs
irqchip: orion: clear bridge cause register on init
The check should be for setup function pointer.
This patch fixes NULL pointer dereference issue for NCI
based NFC driver which doesn't define setup handler.
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Pull USB fixes from Greg KH:
"Here are a number of USB fixes for reported issues for 3.14-rc4
The majority of these are for USB gadget, phy, and musb driver issues.
And there's a few new device ids thrown in for good measure"
* tag 'usb-3.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: chipidea: need to mask when writting endptflush and endptprime
usb: musb: correct use of schedule_delayed_work()
usb: phy: msm: fix compilation errors when !CONFIG_PM_SLEEP
usb: gadget: fix NULL pointer dereference
usb: gadget: printer: using gadget_is_otg to check otg support at runtime
phy: let phy_provider_register be the last step in registering PHY
phy-core: Don't allow building phy-core as a module
phy-core: Don't propagate -ENOSUPP from phy_pm_runtime_get_sync to caller
phy-core: phy_get: Leave error logging to the caller
phy,phy-bcm-kona-usb2.c: Add dependency on HAS_IOMEM
usb: musb: correct use of schedule_delayed_work()
usb: musb: do not sleep in atomic context
USB: serial: option: blacklist interface 4 for Cinterion PHS8 and PXS8
USB: EHCI: add delay during suspend to prevent erroneous wakeups
usb: gadget: bcm63xx_udc: fix build failure on DMA channel code
usb: musb: do not sleep in atomic context
usb: gadget: s3c2410_udc: Fix build error
usb: musb: core: Fix remote-wakeup resume
usb: musb: host: Fix SuperSpeed hub enumeration
usb: musb: fix obex in g_nokia.ko causing kernel panic
Pull TTY revert from Greg KH:
"Here is a single commit, a revert of a sysfs file change that ended up
breaking a userspace tool"
* tag 'tty-3.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
Revert "tty: Set correct tty name in 'active' sysfs attribute"
Pull staging tree fix from Greg KH:
"Here is a single android driver fix for 3.14-rc4 that fixes a reported
problem in the binder driver"
* tag 'staging-3.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: binder: Fix death notifications
Pull char/misc fix from Greg KH:
"Here is a single commit, to fix a reported problem in the mei driver"
* tag 'char-misc-3.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
mei: set client's read_cb to NULL when flow control fails
Add myself as an additional maintainer for the Broadcom mobile
SoCs.
Signed-off-by: Matt Porter <mporter@linaro.org>
Acked-by: Christian Daudt <bcm@fixthebug.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
ASoC: Fixes for v3.14
A few fixes, all driver speccific ones. The DaVinci ones aren't as
clear as they should be from the subject lines on the commits but they
fix issues which will prevent correct operation in some use cases and
only affect that particular driver so are reasonably safe.
# gpg: Signature made Wed 19 Feb 2014 13:23:13 JST using RSA key ID 7EA229BD
# gpg: Good signature from "Mark Brown <broonie@sirena.org.uk>"
# gpg: aka "Mark Brown <broonie@debian.org>"
# gpg: aka "Mark Brown <broonie@kernel.org>"
# gpg: aka "Mark Brown <broonie@tardis.ed.ac.uk>"
# gpg: aka "Mark Brown <broonie@linaro.org>"
# gpg: aka "Mark Brown <Mark.Brown@linaro.org>"
codec->control_data contains a pointer to the regmap struct of the device, not
to the device private data. Use snd_soc_codec_get_drvdata() instead.
The issue was introduced in commit 29fdf4fbbe ("ASoC: sta32x: Convert to
regmap").
Fixes: 29fdf4fbbe (ASoC: sta32x: Convert to regmap)
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org
Pull scheduler fixes from Ingo Molnar:
"Misc fixlets: a fair number of them resulting from the new
SCHED_DEADLINE code"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Remove useless dl_nr_total
sched/deadline: Test for CPU's presence explicitly
sched: Add 'flags' argument to sched_{set,get}attr() syscalls
sched: Fix information leak in sys_sched_getattr()
sched,numa: add cond_resched to task_numa_work
sched/core: Make dl_b->lock IRQ safe
sched/core: Fix sched_rt_global_validate
sched/deadline: Fix overflow to handle period==0 and deadline!=0
sched/deadline: Fix bad accounting of nr_running
Pull hwmon fix from Guenter Roeck:
"Fix writing the minimum temperature in max1668 driver"
* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (max1668) Fix writing the minimum temperature
Pull xfs fixes from Dave Chinner:
"This is the first pull request I've had to do for you, so I'm still
sorting things out. The reason I'm sending this and not Ben should be
obvious from the first commit below - SGI has stepped down from the
XFS maintainership role. As such, I'd like to take another
opportunity to thank them for their many years of effort maintaining
XFS and supporting the XFS community that they developed from the
ground up.
So I haven't had time to work things like signed tags into my
workflows yet, so this is just a repo branch I'm asking you to pull
from. And yes, I named the branch -rc4 because I wanted the fixes in
rc4, not because the branch was for merging into -rc3. Probably not
right, either.
Anyway, I should have everything sorted out by the time the next merge
window comes around. If there's anything that you don't like in the
pull req, feel free to flame me unmercifully.
The changes are fixes for recent regressions and important thinkos in
verification code:
- a log vector buffer alignment issue on ia32
- timestamps on truncate got mangled
- primary superblock CRC validation fixes and error message
sanitisation"
* 'xfs-fixes-for-3.14-rc4' of git://oss.sgi.com/xfs/xfs:
xfs: limit superblock corruption errors to actual corruption
xfs: skip verification on initial "guess" superblock read
MAINTAINERS: SGI no longer maintaining XFS
xfs: xfs_sb_read_verify() doesn't flag bad crcs on primary sb
xfs: ensure correct log item buffer alignment
xfs: ensure correct timestamp updates from truncate
Currently we generate a new fragmentation id on UFO segmentation. It
is pretty hairy to identify the correct net namespace and dst there.
Especially tunnels use IFF_XMIT_DST_RELEASE and thus have no skb_dst
available at all.
This causes unreliable or very predictable ipv6 fragmentation id
generation while segmentation.
Luckily we already have pregenerated the ip6_frag_id in
ip6_ufo_append_data and can use it here.
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Problem statement: 1) both paths (primary path1 and alternate
path2) are up after the association has been established i.e.,
HB packets are normally exchanged, 2) path2 gets inactive after
path_max_retrans * max_rto timed out (i.e. path2 is down completely),
3) now, if a transmission times out on the only surviving/active
path1 (any ~1sec network service impact could cause this like
a channel bonding failover), then the retransmitted packets are
sent over the inactive path2; this happens with partial failover
and without it.
Besides not being optimal in the above scenario, a small failure
or timeout in the only existing path has the potential to cause
long delays in the retransmission (depending on RTO_MAX) until
the still active path is reselected. Further, when the T3-timeout
occurs, we have active_patch == retrans_path, and even though the
timeout occurred on the initial transmission of data, not a
retransmit, we end up updating retransmit path.
RFC4960, section 6.4. "Multi-Homed SCTP Endpoints" states under
6.4.1. "Failover from an Inactive Destination Address" the
following:
Some of the transport addresses of a multi-homed SCTP endpoint
may become inactive due to either the occurrence of certain
error conditions (see Section 8.2) or adjustments from the
SCTP user.
When there is outbound data to send and the primary path
becomes inactive (e.g., due to failures), or where the SCTP
user explicitly requests to send data to an inactive
destination transport address, before reporting an error to
its ULP, the SCTP endpoint should try to send the data to an
alternate __active__ destination transport address if one
exists.
When retransmitting data that timed out, if the endpoint is
multihomed, it should consider each source-destination address
pair in its retransmission selection policy. When retransmitting
timed-out data, the endpoint should attempt to pick the most
divergent source-destination pair from the original
source-destination pair to which the packet was transmitted.
Note: Rules for picking the most divergent source-destination
pair are an implementation decision and are not specified
within this document.
So, we should first reconsider to take the current active
retransmission transport if we cannot find an alternative
active one. If all of that fails, we can still round robin
through unkown, partial failover, and inactive ones in the
hope to find something still suitable.
Commit 4141ddc02a ("sctp: retran_path update bug fix") broke
that behaviour by selecting the next inactive transport when
no other active transport was found besides the current assoc's
peer.retran_path. Before commit 4141ddc02a, we would have
traversed through the list until we reach our peer.retran_path
again, and in case that is still in state SCTP_ACTIVE, we would
take it and return. Only if that is not the case either, we
take the next inactive transport.
Besides all that, another issue is that transports in state
SCTP_UNKNOWN could be preferred over transports in state
SCTP_ACTIVE in case a SCTP_ACTIVE transport appears after
SCTP_UNKNOWN in the transport list yielding a weaker transport
state to be used in retransmission.
This patch mostly reverts 4141ddc02a, but also rewrites
this function to introduce more clarity and strictness into
the code. A strict priority of transport states is enforced
in this patch, hence selection is active > unkown > partial
failover > inactive.
Fixes: 4141ddc02a ("sctp: retran_path update bug fix")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Acked-by: Vlad Yasevich <yasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes bug introduced by:
commit 1d4c8c2984
"neigh: restore old behaviour of default parms values"
The thing is that in neigh_sysctl_register, extra1 and extra2 which were
previously set for NEIGH_VAR_GC_* are overwritten. That leads to
nonsense int limits for gc_* variables. So fix this by not touching
extra* fields for gc_* variables.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes two bugs in fastopen :
1) The tcp_sendmsg(..., @size) argument was ignored.
Code was relying on user not fooling the kernel with iovec mismatches
2) When MTU is about 64KB, tcp_send_syn_data() attempts order-5
allocations, which are likely to fail when memory gets fragmented.
Fixes: 783237e8da ("net-tcp: Fast Open client - sending SYN-data")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Tested-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ying Xue says:
====================
tipc: clean up components initialization code
In this series, we will fix a regression issue involved by commit
6e967adf7(tipc: relocate common functions from media to bearer)
But before the issue is fixed, we firstly adjust the process of
components initialization so as to remove all enabled flags from
necessary tipc components. Otherwise, without the change, we also
have to add an extra enabled flag into bearer layer indicating
whether bearer setup is finshed or not.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Accidentally a side effect is involved by commit 6e967adf7(tipc:
relocate common functions from media to bearer). Now tipc stack
handler of receiving packets from netdevices as well as netdevice
notification handler are registered when bearer is enabled rather
than tipc module initialization stage, but the two handlers are
both unregistered in tipc module exit phase. If tipc module is
inserted and then immediately removed, the following warning
message will appear:
"dev_remove_pack: ffffffffa0380940 not found"
This is because in module insertion stage tipc stack packet handler
is not registered at all, but in module exit phase dev_remove_pack()
needs to remove it. Of course, dev_remove_pack() cannot find tipc
protocol handler from the kernel protocol handler list so that the
warning message is printed out.
But if registering the two handlers is adjusted from enabling bearer
phase into inserting module stage, the warning message will be
eliminated. Due to this change, tipc_core_start_net() and
tipc_core_stop_net() can be deleted as well.
Reported-by: Wang Weidong <wangweidong1@huawei.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When tipc module is inserted, many tipc components are initialized
one by one. During the initialization period, if one of them is
failed, tipc_core_stop() will be called to stop all components
whatever corresponding components are created or not. To avoid to
release uncreated ones, relevant components have to add necessary
enabled flags indicating whether they are created or not.
But in the initialization stage, if one component is unsuccessfully
created, we will just destroy successfully created components before
the failed component instead of all components. All enabled flags
defined in components, in turn, become redundant. Additionally it's
also unnecessary to identify whether table.types is NULL in
tipc_nametbl_stop() because name stable has been definitely created
successfully when tipc_nametbl_stop() is called.
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This fixes bug introduced in 667a6b7a (regulator: max14577: Add missing
of_node_put). The DTS parsing function returned number of matched
regulators as success status which then was compared against 0 in probe.
Result was a probe fail after successful parsing the DTS:
max14577-regulator: probe of max14577-regulator failed with error 2
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviwed-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
This reverts commit c4a391b53a. Dave
Chinner <david@fromorbit.com> has reported the commit may cause some
inodes to be left out from sync(2). This is because we can call
redirty_tail() for some inode (which sets i_dirtied_when to current time)
after sync(2) has started or similarly requeue_inode() can set
i_dirtied_when to current time if writeback had to skip some pages. The
real problem is in the functions clobbering i_dirtied_when but fixing
that isn't trivial so revert is a safer choice for now.
CC: stable@vger.kernel.org # >= 3.13
Signed-off-by: Jan Kara <jack@suse.cz>
Given that bip->bip_iter.bi_size is decremented after bio_advance() ->
bio_integrity_advance() is called, the BUG_ON() in bio_integrity_verify()
ends up tripping in v3.14-rc1 code with the advent of immutable biovecs
in:
commit d57a5f7c66
Author: Kent Overstreet <kmo@daterainc.com>
Date: Sat Nov 23 17:20:16 2013 -0800
bio-integrity: Convert to bvec_iter
Given that there is no easy way to ascertain the original bi_size
value, go ahead and drop this BUG_ON().
Reported-by: Sagi Grimberg <sagig@dev.mellanox.co.il>
Reported-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
irqchip mvebu fixes for v3.14
- orion:
- fixes for clearing bridge cause register, and clearing stale interrupts
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Pull devicetree fixes from Grant Likely:
"Device tree compatible match order bug fix
This branch contains a bug fix for the way devicetree code identifies
the type of device. Device drivers can contain a list of
of_device_ids, but it more than one entry will match, then the device
driver may choose the wrong one. Commit 105353145e, "match each node
compatible against all given matches first", was queued for v3.14 but
ended up causing other bugs. Commit 06b29e76a7 attempted to fix it
but it had other bugs. Merely reverting the fix and waiting until
v3.15 isn't a good option because there is code in v3.14 that depends
on the revised behaviour to boot.
This branch should finally fixes the problem correctly. This time
instead of just hoping that the patch is correct, this branch also
adds new testcases that validate the behaviour.
The changes in this branch are larger than I would like for a -rc
pull, but moving the test case data out of out of arch/arm so that it
could be validated on other architectures was important"
* tag 'dt-for-linus' of git://git.secretlab.ca/git/linux:
of: Add self test for of_match_node()
of: Move testcase FDT data into drivers/of
of: reimplement the matching method for __of_match_node()
Revert "of: search the best compatible match first in __of_match_node()"
Pull watchdog fix from Wim Van Sebroeck:
"It corrects the error code when no device was found for w83697hf_wdt"
* git://www.linux-watchdog.org/linux-watchdog:
watchdog: w83697hf_wdt: return ENODEV if no device was found
Enabling SPARSE_IRQ shows up a bug in the irq-orion bridge interrupt
handler. The bridge interrupt is implemented using a single generic
chip. Thus the parameter passed to irq_get_domain_generic_chip()
should always be zero.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Fixes: 9dbd90f17e ("irqchip: Add support for Marvell Orion SoCs")
Cc: <stable@vger.kernel.org> # v3.11+
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
When using BTS on Core i7-4*, I get the below kernel warning.
$ perf record -c 1 -e branches:u ls
Message from syslogd@labpc1501 at Nov 11 15:49:25 ...
kernel:[ 438.317893] Uhhuh. NMI received for unknown reason 31 on CPU 2.
Message from syslogd@labpc1501 at Nov 11 15:49:25 ...
kernel:[ 438.317920] Do you have a strange power saving mode enabled?
Message from syslogd@labpc1501 at Nov 11 15:49:25 ...
kernel:[ 438.317945] Dazed and confused, but trying to continue
Make intel_pmu_handle_irq() take the full exit path when returning early.
Cc: eranian@google.com
Cc: peterz@infradead.org
Cc: mingo@kernel.org
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392425048-5309-1-git-send-email-andi@firstfloor.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
ENDPTFLUSH and ENDPTPRIME registers are set by software and clear
by hardware. There is a bit for each endpoint. When we are setting
a bit for an endpoint we should make sure we do not touch other
endpoint bit. There is a race condition if the hardware clear the
bit between the read and the write in hw_write.
Cc: stable <stable@vger.kernel.org> # 3.11+
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Matthieu CASTET <matthieu.castet@parrot.com>
Tested-by: Michael Grzeschik <mgrzeschik@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We're copying the on-stack structure to userspace, but forgot to give
the right number of bytes to copy. This allows the calling process to
obtain up to PAGE_SIZE bytes from the stack (and possibly adjacent
kernel memory).
This fix copies only as much as we actually have on the stack
(attr->size defaults to the size of the struct) and leaves the rest of
the userspace-provided buffer untouched.
Found using kmemcheck + trinity.
Fixes: d50dde5a10 ("sched: Add new scheduler syscalls to support an extended scheduling parameters ABI")
Cc: Dario Faggioli <raistlin@linux.it>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392585857-10725-1-git-send-email-vegard.nossum@oracle.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fix this lockdep warning:
[ 44.804600] =========================================================
[ 44.805746] [ INFO: possible irq lock inversion dependency detected ]
[ 44.805746] 3.14.0-rc2-test+ #14 Not tainted
[ 44.805746] ---------------------------------------------------------
[ 44.805746] bash/3674 just changed the state of lock:
[ 44.805746] (&dl_b->lock){+.....}, at: [<ffffffff8106ad15>] sched_rt_handler+0x132/0x248
[ 44.805746] but this lock was taken by another, HARDIRQ-safe lock in the past:
[ 44.805746] (&rq->lock){-.-.-.}
and interrupts could create inverse lock ordering between them.
[ 44.805746]
[ 44.805746] other info that might help us debug this:
[ 44.805746] Possible interrupt unsafe locking scenario:
[ 44.805746]
[ 44.805746] CPU0 CPU1
[ 44.805746] ---- ----
[ 44.805746] lock(&dl_b->lock);
[ 44.805746] local_irq_disable();
[ 44.805746] lock(&rq->lock);
[ 44.805746] lock(&dl_b->lock);
[ 44.805746] <Interrupt>
[ 44.805746] lock(&rq->lock);
by making dl_b->lock acquiring always IRQ safe.
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392107067-19907-3-git-send-email-juri.lelli@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
While debugging the crash with the bad nr_running accounting, I hit
another bug where, after running my sched deadline test, I was getting
failures to take a CPU offline. It was giving me a -EBUSY error.
Adding a bunch of trace_printk()s around, I found that the cpu
notifier that called sched_cpu_inactive() was returning a failure. The
overflow value was coming up negative?
Talking this over with Juri, the problem is that the total_bw update was
suppose to be made by dl_overflow() which, during my tests, seemed to
not be called. Adding more trace_printk()s, it wasn't that it wasn't
called, but it exited out right away with the check of new_bw being
equal to p->dl.dl_bw. The new_bw calculates the ratio between period and
runtime. The bug is that if you set a deadline, you do not need to set
a period if you plan on the period being equal to the deadline. That
is, if period is zero and deadline is not, then the system call should
set the period to be equal to the deadline. This is done elsewhere in
the code.
The fix is easy, check if period is set, and if it is not, then use the
deadline.
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140219135335.7e74abd4@gandalf.local.home
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Rostedt writes:
My test suite was locking up hard when enabling mmiotracer. This was due
to the mmiotracer placing all but one CPU offline. I found this out
when I was able to reproduce the bug with just my stress-cpu-hotplug
test. This bug baffled me because it would not always trigger, and
would only trigger on the first run after boot up. The
stress-cpu-hotplug test would crash hard the first run, or never crash
at all. But a new reboot may cause it to crash on the first run again.
I spent all week bisecting this, as I couldn't find a consistent
reproducer. I finally narrowed it down to the sched deadline patches,
and even more peculiar, to the commit that added the sched
deadline boot up self test to the latency tracer. Then it dawned on me
to what the bug was.
All it took was to run a task under sched deadline to screw up the CPU
hot plugging. This explained why it would lock up only on the first run
of the stress-cpu-hotplug test. The bug happened when the boot up self
test of the schedule latency tracer would test a deadline task. The
deadline task would corrupt something that would cause CPU hotplug to
fail. If it didn't corrupt it, the stress test would always work
(there's no other sched deadline tasks that would run to cause
problems). If it did corrupt on boot up, the first test would lockup
hard.
I proved this theory by running my deadline test program on another box,
and then run the stress-cpu-hotplug test, and it would now consistently
lock up. I could run stress-cpu-hotplug over and over with no problem,
but once I ran the deadline test, the next run of the
stress-cpu-hotplug would lock hard.
After adding lots of tracing to the code, I found the cause. The
function tracer showed that migrate_tasks() was stuck in an infinite
loop, where rq->nr_running never equaled 1 to break out of it. When I
added a trace_printk() to see what that number was, it was 335 and
never decrementing!
Looking at the deadline code I found:
static void __dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags) {
dequeue_dl_entity(&p->dl);
dequeue_pushable_dl_task(rq, p);
}
static void dequeue_task_dl(struct rq *rq, struct task_struct *p, int flags) {
update_curr_dl(rq);
__dequeue_task_dl(rq, p, flags);
dec_nr_running(rq);
}
And this:
if (dl_runtime_exceeded(rq, dl_se)) {
__dequeue_task_dl(rq, curr, 0);
if (likely(start_dl_timer(dl_se, curr->dl.dl_boosted)))
dl_se->dl_throttled = 1;
else
enqueue_task_dl(rq, curr, ENQUEUE_REPLENISH);
if (!is_leftmost(curr, &rq->dl))
resched_task(curr);
}
Notice how we call __dequeue_task_dl() and in the else case we
call enqueue_task_dl()? Also notice that dequeue_task_dl() has
underscores where enqueue_task_dl() does not. The enqueue_task_dl()
calls inc_nr_running(rq), but __dequeue_task_dl() does not. This is
where we get nr_running out of sync.
[snip]
Another point where nr_running can get out of sync is when the dl_timer
fires:
dl_se->dl_throttled = 0;
if (p->on_rq) {
enqueue_task_dl(rq, p, ENQUEUE_REPLENISH);
if (task_has_dl_policy(rq->curr))
check_preempt_curr_dl(rq, p, 0);
else
resched_task(rq->curr);
This patch does two things:
- correctly accounts for throttled tasks (that are now considered
!running);
- fixes the bug, updating nr_running from {inc,dec}_dl_tasks(),
since we risk to update it twice in some situations (e.g., a
task is dequeued while it has exceeded its budget).
Cc: mingo@redhat.com
Cc: torvalds@linux-foundation.org
Cc: akpm@linux-foundation.org
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392884379-13744-1-git-send-email-juri.lelli@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Most WDT driver modules return ENODEV during modprobe if
no valid device was found, but w83697hf_wdt returns EIO.
Let w83697hf_wdt return ENODEV.
Signed-off-by: Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
