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691,473 commits

Author SHA1 Message Date
Peter Hurley
5e00bbfbc5 tty: Fix merge of "tty: Refactor tty_open()"
Commit e9036d0662 ("tty: Drop krefs for interrupted tty lock")
fixed a tty reference counting problem introduced in
commit 0bfd464d3f ("tty: Wait interruptibly for tty lock on reopen"),
so v4.5.0 is correct.

However, commit d6203d0c7b ("tty: Refactor tty_open()") moved the
relevant code for 4.6-rc1; correct the merge.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-31 20:49:39 -07:00
Daniel Vetter
72b9ff0612 drm/udl: Use unlocked gem unreferencing
For drm_gem_object_unreference callers are required to hold
dev->struct_mutex, which these paths don't. Enforcing this requirement
has become a bit more strict with

commit ef4c6270bf
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Thu Oct 15 09:36:25 2015 +0200

    drm/gem: Check locking in drm_gem_object_unreference

Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-04-01 13:22:33 +10:00
Rob Clark
7779c5e23c drm/dp: move hw_mutex up the call stack
1) don't let other threads trying to bang on aux channel interrupt the
defer timeout/logic
2) don't let other threads interrupt the i2c over aux logic

Technically, according to people who actually have the DP spec, this
should not be required.  In practice, it makes some troublesome Dell
monitor (and perhaps others) work, so probably a case of "It's compliant
if it works with windows" on the hw vendor's part..

v2: rebased to come before DPCD/AUX logging patch for easier backport
to stable branches.

Reported-by: Dave Wysochanski <dwysocha@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1274157
Cc: stable@vger.kernel.org
Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-04-01 13:17:36 +10:00
Dave Airlie
5456248d66 Merge branch 'drm-rockchip-next-fixes-2016-03-28' of https://github.com/markyzq/kernel-drm-rockchip into drm-fixes
bunch of rockchip fixes.

* 'drm-rockchip-next-fixes-2016-03-28' of https://github.com/markyzq/kernel-drm-rockchip:
  drm/rockchip: dw_hdmi: Don't call platform_set_drvdata()
  drm/rockchip: vop: Fix vop crtc cleanup
  drm/rockchip: dw_hdmi: Call drm_encoder_cleanup() in error path
  drm/rockchip: vop: Disable planes when disabling CRTC
  drm/rockchip: vop: Don't reject empty modesets
  drm/rockchip: cancel pending vblanks on close
  drm/rockchip: vop: fix crtc size in plane check
2016-04-01 13:14:24 +10:00
Dave Airlie
90516d89cd Merge branch 'msm-fixes-4.6-rc1' of git://people.freedesktop.org/~robclark/linux into drm-fixes
two minor msm fixes.

* 'msm-fixes-4.6-rc1' of git://people.freedesktop.org/~robclark/linux:
  drm/msm: fix typo in the !COMMON_CLK case
  drm/msm: fix bug after preclose removal
2016-04-01 13:14:10 +10:00
Dave Airlie
2f4fcb3eaf Merge branch 'drm-next-4.6' of git://people.freedesktop.org/~agd5f/linux into drm-fixes
Just a few fixes for 4.6 this week:
- Add some SI DPM quirks
- Improve the ACP Kconfig text
- Additional BO pinning checks

* 'drm-next-4.6' of git://people.freedesktop.org/~agd5f/linux:
  drm/amdgpu: Don't move pinned BOs
  drm/radeon: Don't move pinned BOs
  drm/radeon: add a dpm quirk for all R7 370 parts
  drm/radeon: add another R7 370 quirk
  drm/radeon: add a dpm quirk for sapphire Dual-X R7 370 2G D5
  drm/amd: Beef up ACP Kconfig menu text
2016-04-01 13:13:34 +10:00
Eric Anholt
0b27c02a7f drm: Add an encoder and connector type enum for DPI.
Right now exynos is exposing DPI as a TMDS encoder and VGA connector,
which seems rather misleading.  This isn't just an internal detail,
since xrandr actually exposes "VGA" as the output name.  Define some
new enums so that vc4's DPI can have a more informative name.

I considered other names for the connector as well.  For VC4, the
Adafruit DPI kippah takes the 28 GPIO pins and routes them to a
standard-ish 40-pin FPC connector, but "40-pin FPC" doesn't uniquely
identify an ordering of pins (apparently some other orderings exist),
doesn't explain things as well for the user (who, if anything, knows
their product is a DPI kippah/panel combo), and actually doesn't have
to exist (one could connect the 28 GPIOs directly to something else).
Simply "DPI" seems like a good compromise name to distinguish from the
HDMI, DSI, and TV connectors .

Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2016-03-31 18:39:39 -07:00
Martin K. Petersen
f08bb1e0db sd: Fix excessive capacity printing on devices with blocks bigger than 512 bytes
During revalidate we check whether device capacity has changed before we
decide whether to output disk information or not.

The check for old capacity failed to take into account that we scaled
sdkp->capacity based on the reported logical block size. And therefore
the capacity test would always fail for devices with sectors bigger than
512 bytes and we would print several copies of the same discovery
information.

Avoid scaling sdkp->capacity and instead adjust the value on the fly
when setting the block device capacity and generating fake C/H/S
geometry.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: <stable@vger.kernel.org>
Reported-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Hannes Reinicke <hare@suse.de>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2016-03-31 20:59:08 -04:00
Jaehoon Chung
e70c7ae1c5 ARM: dts: exynos: Add MSHC2 DT node for SD card for exynos3250-artik5-eval board
This patch adds MSHC (Mobile Storage Host Controller) DT node for
Exynos3250 SoC. MSHC is an interface between the system and the SD card.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
2016-04-01 09:22:46 +09:00
Chanwoo Choi
b004a34bd0 ARM: dts: exynos: Add exynos3250-artik5 dtsi file for ARTIK5 module
This patch adds the Device Tree source for Samsung ARTIK5 module[1]
based on Exynos3250 SoC. The ARTIK5 module includes the following
devices:
 - Application Processor (Samsung Exynos3250)
 - WiFi/BT Combo chip (Broadcom4354)
 - PMIC (Samsung S2MPS14)
 - eMMC (4GB)
 - DRAM LPDDR3 (512MB)
 - Connectors pin (60 Pins x 3 set)

Also, this patch adds the ARTIK5 evaluation board[2] dts file which includes
the ARTIK5 module[1] and have the devices such as sound codec, sd card port,
ethernet port, uart port and so on.

[1] https://www.artik.io/hardware/artik-5
[2] http://www.digikey.com/product-search/en?FV=ffecca14

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
2016-04-01 09:21:32 +09:00
Chanwoo Choi
92173e6ac2 ARM: dts: exynos: Add MSHC2 DT node for Exynos3250 SoC
This patch adds the MSHC2 (Mobile Storage Host Controller) Device Tree node for
Exynos3250 SoC.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
2016-04-01 09:21:06 +09:00
Pankaj Dubey
ecaba514f4 ARM: dts: exynos: Add UART2 DT node for Exynos3250 SoC
This patch add the UART2 Device Tree node for Exynos3250 SoC.

Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
2016-04-01 09:20:53 +09:00
Chanwoo Choi
d278c808f5 ARM: dts: exynos: Add initial gpio setting of MMC2 device for exynos3250-monk
This patch adds initial pin configuration of MMC2 device on exynos3250-monk
board because the MMC2 gpio pin (gpk2[0-6]) are NC (not connected) state.

Suggested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
2016-04-01 09:20:47 +09:00
Chanwoo Choi
40bbd191fc ARM: dts: exynos: Add initial pin configuration for exynos3250-rinato
This patch adds initial pin configuration using pinctrl subsystem
to reduce leakage power-consumption of gpio pins in normal state.
All pins included in this patch are NC (not connected) pin.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
2016-04-01 09:20:44 +09:00
Peter Hurley
da5a0fc674 tty: Fix UML console breakage
User-Mode Linux supplies an alternate TTY_MAJOR driver for stdio console,
so the noctty check in tty_open() must apply only to VT driver tty0
devnode and not the UML console driver tty0 devnode.

Fixes: 11e1d4aa4d ("tty: Consolidate noctty checks in tty_open()")
Reported-by: Richard Weinberger <richard.weinberger@gmail.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-31 17:14:14 -07:00
Krzysztof Kozlowski
a8b41ea4ba Addition of the Exynos3250 SoC's UART2 and MMC2 clocks.
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Merge tag 'clk-v4.7-exynos3250' of git://linuxtv.org/snawrocki/samsung into for-v4.7/dt-exynos3250-artik5

Addition of the Exynos3250 SoC's UART2 and MMC2 clocks.

Pull clocks used on Exynos3250-based Artik-5 board.
2016-04-01 02:09:43 +02:00
Rasmus Villemoes
423de92f56 mei: bus: use scnprintf in *_show
There's no reason to duplicate the logic provided by scnprintf().

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-31 16:43:05 -07:00
Moise Gergaud
5ba10dd4a1 ASoC: sti: correct typo errors
Signed-off-by: Moise Gergaud <moise.gergaud@st.com>
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-31 15:59:26 -07:00
Daniele Palmas
79f4223257 net: usb: cdc_ncm: adding Telit LE910 V2 mobile broadband card
Telit LE910 V2 is a mobile broadband card with no ARP capabilities:
the patch makes this device to use wwan_noarp_info struct

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Reviewed-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-31 17:15:35 -04:00
Nicolas Dichtel
c57c7a95da rtnl: fix msg size calculation in if_nlmsg_size()
Size of the attribute IFLA_PHYS_PORT_NAME was missing.

Fixes: db24a9044e ("net: add support for phys_port_name")
CC: David Ahern <dsahern@gmail.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-31 16:49:54 -04:00
Mark Brown
2ed94f6fde regmap: mmio: Explicitly say little endian is the defualt in the bus config
Otherwise the DT parsing will default to big endian if nothing is
specified.

Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-03-31 13:41:12 -07:00
Paul E. McKenney
480b1eb659 rcutorture: Convert test duration to seconds early
This commit converts test duration from minutes to seconds early on
in order to prepare for upcoming OS-jitter-injection changes.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:39:53 -07:00
Paul E. McKenney
fb2c66af10 torture: Kill qemu, not parent process
The current hang-check machinery in the rcutorture scripts uses "$!" of
a parenthesized bash statement to capture the pid.  Unfortunately, this
captures not qemu's pid, but rather that of its parent that implements
the parenthesized statement.  This commit therefore adjusts things so as
to capture qemu's actual pid, which then allows the script to actually
kill qemu in event of a kernel hang.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:39:53 -07:00
Paul E. McKenney
9eb5188a07 torture: Clarify refusal to run more than one torture test
This commit clarifies error messages -- you only get to run one torture
test at a time!

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:39:52 -07:00
Anna-Maria Gleixner
de26ca19a5 rcutorture: Consider FROZEN hotplug notifier transitions
The hotplug notifier rcutorture_cpu_notify() doesn't consider the
corresponding CPU_XXX_FROZEN transitions. They occur on
suspend/resume and are usually handled the same way as the
corresponding non frozen transitions.

Mask the switch case action argument with '~CPU_TASKS_FROZEN' to map
CPU_XXX_FROZEN hotplug transitions on corresponding non-frozen
transitions.

Cc: Josh Triplett <josh@joshtriplett.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:39:52 -07:00
Paul E. McKenney
67522beecf rcutorture: Remove redundant initialization to zero
The current code initializes the global per-CPU variables
rcu_torture_count and rcu_torture_batch to zero.  However, C does this
initialization by default, and explicit initialization of per-CPU
variables now needs a different syntax if "make tags" is to work.
This commit therefore removes the initialization.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:39:51 -07:00
Artem Savkov
e6fb1fc108 rcuperf: Do not wake up shutdown wait queue if "shutdown" is false.
After finishing its tests rcuperf tries to wake up shutdown_wq even if
"shutdown" param is set to false, resulting in a wake_up() call on an
unitialized wait_queue_head_t which leads to "BUG: spinlock bad magic" and
"BUG: unable to handle kernel NULL pointer dereference".

Fix by checking "shutdown" param before waking up the queue.

Signed-off-by: Artem Savkov <artem.savkov@gmail.com>
2016-03-31 13:39:51 -07:00
Paul E. McKenney
dba6f1bab8 rcutorture: Add largish-system rcuperf scenario
This commit adds an rcuperf scenario named TREE54 that uses 54 CPUs and
provides a four-level rcu_node combining tree.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:39:50 -07:00
Paul E. McKenney
620316e52a rcutorture: Avoid RCU CPU stall warning and RT throttling
Running rcuperf can result in RCU CPU stall warnings and RT throttling.
These occur because on of the real-time writer processes does
ftrace_dump() while still running at real-time priority.  This commit
therefore prevents these problems by setting the writer thread back to
SCHED_NORMAL (AKA SCHED_OTHER) before doing ftrace_dump().

In addition, this commit adds a small fixed delay before dumping ftrace
buffer in order to decrease the probability that this dumping will
interfere with other writers' grace periods.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:39:47 -07:00
Paul E. McKenney
df37e66bfd rcutorture: Add rcuperf holdoff boot parameter to reduce interference
Boot-time activity can legitimately grab CPUs for extended time periods,
so the commit adds a boot parameter to delay the start of the performance
test until boot has completed.  Defaults to 10 seconds.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:38:58 -07:00
Paul E. McKenney
2b03d03845 rcutorture: Make scripts analyze rcuperf trace data, if present
The rcuperf event-trace data is more accurate than are the rcuperf
printk()s because locking keeps things ordered.  This commit therefore
parses and analyzes this event-trace data if present, and falls back on
the printk()s otherwise.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:38:57 -07:00
Paul E. McKenney
ac2bb275e8 rcutorture: Make rcuperf collect expedited event-trace data
This commit enables ftrace in the rcuperf TREE kernel build and adds
an ftrace_dump() at the end of rcuperf processing.  This data will be
used to measure the actual durations of the expedited grace periods
without the added delays inherent in the kernel-module measurements.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:38:53 -07:00
Paul E. McKenney
e588f35492 rcutorture: Print measure of batching efficiency
This commit adds a line giving the number of grace periods, the number
of batches, and the ratio.  The larger the ratio, the greater the
batching efficiency.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:37:40 -07:00
Paul E. McKenney
2094c99558 rcutorture: Set rcuperf writer kthreads to real-time priority
This commit forces more deterministic update-side behavior by setting
rcuperf's rcu_perf_writer() kthreads to real-time priority.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:37:39 -07:00
Paul E. McKenney
6b558c4c7a rcutorture: Bind rcuperf reader/writer kthreads to CPUs
This commit forces more deterministic behavior by binding rcuperf's
rcu_perf_reader() and rcu_perf_writer() kthreads to their respective
CPUs.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:37:39 -07:00
Paul E. McKenney
bdea9e3477 rcutorture: Documentation for rcuperf kernel parameters
This commit adds documentation for the new rcuperf module's kernel
boot parameters.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:37:38 -07:00
Paul E. McKenney
8704baab9b rcutorture: Add RCU grace-period performance tests
This commit adds a new rcuperf module that carries out simple performance
tests of RCU grace periods.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:37:38 -07:00
Paul E. McKenney
291783b8ad rcutorture: Expedited-GP batch progress access to torturing
This commit provides rcu_exp_batches_completed() and
rcu_exp_batches_completed_sched() functions to allow torture-test modules
to check how many expedited grace period batches have completed.
These are analogous to the existing rcu_batches_completed(),
rcu_batches_completed_bh(), and rcu_batches_completed_sched() functions.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:37:37 -07:00
Paul E. McKenney
9efafb8849 rcutorture: Allow for rcupdate.rcu_normal
Currently, rcu_torture_writer() checks only for rcu_gp_is_expedited()
when deciding whether or not to do dynamic control of RCU expediting.
This means that if rcupdate.rcu_normal is specified, rcu_torture_writer()
will attempt to dynamically control RCU expediting, but will nonetheless
only test normal RCU grace periods.  This commit therefore adds a check
for !rcu_gp_is_normal(), and prints a message and desists from testing
dynamic control of RCU expediting when doing so is futile.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:37:37 -07:00
Paul E. McKenney
fd35be623a rcutorture: Update scripting to accommodate rcuperf
This commit adds the scripting changes to add support for the shiny
new rcuperf kernel module.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:37:36 -07:00
Paul E. McKenney
5dffed1e57 rcu: Dump ftrace buffer when kicking grace-period kthread
If it is necessary to kick the grace-period kthread, that is a good
time to dump the trace buffer in order to learn why kicking was needed.
This commit therefore does the dump.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:36:37 -07:00
Boqun Feng
293e2421fe rcu: Remove superfluous versions of rcu_read_lock_sched_held()
Currently, we have four versions of rcu_read_lock_sched_held(), depending
on the combined choices on PREEMPT_COUNT and DEBUG_LOCK_ALLOC.  However,
there is an existing function preemptible() that already distinguishes
between the PREEMPT_COUNT=y and PREEMPT_COUNT=n cases, and allows these
four implementations to be consolidated down to two.

This commit therefore uses preemptible() to achieve this consolidation.

Note that there could be a small performance regression in the case
of CONFIG_DEBUG_LOCK_ALLOC=y && PREEMPT_COUNT=n.  However, given the
overhead associated with CONFIG_DEBUG_LOCK_ALLOC=y, this should be
down in the noise.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:34:50 -07:00
Paul E. McKenney
8c7c4829a8 rcu: Awaken grace-period kthread if too long since FQS
Recent kernels can fail to awaken the grace-period kthread for
quiescent-state forcing.  This commit is a crude hack that does
a wakeup if a scheduling-clock interrupt sees that it has been
too long since force-quiescent-state (FQS) processing.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:34:50 -07:00
Paul E. McKenney
fcfd0a237b rcu: Make FQS schedule advance only if FQS happened
Currently, the force-quiescent-state (FQS) code in rcu_gp_kthread() can
advance the next FQS even if one was not executed last time.  This can
happen due timeout-duration uncertainty.  This commit therefore avoids
advancing the FQS schedule unless an FQS was just executed.  In the
corner case where an FQS was not executed, but is due now, the code does
a one-jiffy wait.

This change prepares for kthread kicking.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:34:49 -07:00
Paul E. McKenney
86057b80ae rcu: Awaken grace-period kthread when stalled
Recent kernels can fail to awaken the grace-period kthread for
quiescent-state forcing.  This commit is a crude hack that does
a wakeup any time a stall is detected.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:34:49 -07:00
Paul E. McKenney
3b5f668e71 rcu: Overlap wakeups with next expedited grace period
The current expedited grace-period implementation makes subsequent grace
periods wait on wakeups for the prior grace period.  This does not fit
the dictionary definition of "expedited", so this commit allows these two
phases to overlap.  Doing this requires four waitqueues rather than two
because tasks can now be waiting on the previous, current, and next grace
periods.  The fourth waitqueue makes the bit masking work out nicely.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:34:11 -07:00
Paul E. McKenney
aff12cdf86 rcu: Consolidate expedited GP code into exp_funnel_lock()
This commit pulls the grace-period-start counter adjustment and tracing
from synchronize_rcu_expedited() and synchronize_sched_expedited()
into exp_funnel_lock(), thus eliminating some code duplication.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:34:11 -07:00
Paul E. McKenney
179e5dcd1e rcu: Consolidate expedited GP tracing into rcu_exp_gp_seq_snap()
This commit moves some duplicate code from synchronize_rcu_expedited()
and synchronize_sched_expedited() into rcu_exp_gp_seq_snap().  This
doesn't save lines of code, but does eliminate a "tell me twice" issue.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:34:10 -07:00
Paul E. McKenney
4ea3e85b11 rcu: Consolidate expedited GP code into rcu_exp_wait_wake()
Currently, synchronize_rcu_expedited() and rcu_sched_expedited() have
significant duplicate code.  This commit therefore consolidates some of
this code into rcu_exp_wake(), which is now renamed to rcu_exp_wait_wake()
in recognition of its added responsibilities.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:34:10 -07:00
Paul E. McKenney
356051e1de rcu: Add exp_funnel_lock() fastpath
This commit speeds up the low-contention case, especially for systems
with large rcu_node trees, by attempting to directly acquire the
->exp_mutex.  This fastpath checks the leaves and root first in
order to avoid excessive memory contention on the mutex itself.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2016-03-31 13:34:09 -07:00