This patch makes use of mmc_regulator_get_supply() to handle
the vmmc and vqmmc regulators.Also it moves the code handling
the these regulators to dw_mci_set_ios().It turned on the vmmc
and vqmmc during MMC_POWER_UP and MMC_POWER_ON,and turned off
during MMC_POWER_OFF.
Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Some controller is supporting actual clock on SD_CLK_CTRL :: DIV[7:0].
Renesas SH-Mobile SDHI doesn't support,
but, Renesas R-Car SDHI supports it.
This patch adds new TMIO_MMC_CLK_ACTUAL flag for it.
[Kuninori Morimoto: tidyuped for upstreaming]
Tested-by: Nguyen Xuan Nui <nx-nui@jinso.co.jp>
Tested-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: Shinobu Uehara <shinobu.uehara.xc@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds new TMIO_MMC_HAVE_CTL_DMA_REG flag,
and remove Renesas specific #ifdef from tmio driver
Tested-by: Nguyen Xuan Nui <nx-nui@jinso.co.jp>
Tested-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Renesas R-Car SDHI should set reserved bits
on CTL_SDIO_STATUS register when writing.
This patch adds new TMIO_MMC_SDIO_STATUS_QUIRK flags
for this purpose
[Kuninori Morimoto: tidyuped for upstreaming
enabled this flags for all SH-Mobile/R-Car]
Tested-by: Nguyen Xuan Nui <nx-nui@jinso.co.jp>
Tested-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: Shinobu Uehara <shinobu.uehara.xc@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Renesas SDHI has "Multiple Block Transfer Mode" settings
on SD_CMD register which controls CMD12 automatically.
This patch cares it, because
CMD12 is not needed when CMD53 (= SD_IO_RW_EXTENDED)
[Kuninori Morimoto: tidyuped for upstreaming
enabled this flags for all SH-Mobile/R-Car]
Tested-by: Nguyen Xuan Nui <nx-nui@jinso.co.jp>
Tested-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Signed-off-by: Shinobu Uehara <shinobu.uehara.xc@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Basically, SD_BUF0 Tx/Rx addresses are same
in normal TMIO controller,
but, it is different on Renesas R-Car SDHI controller
if it uses DMAC
(Rx address needs to add 0x2000 to Tx address)
This patch adds new .dma_rx_offset and cares it
Tested-by: Nguyen Xuan Nui <nx-nui@jinso.co.jp>
Tested-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
Acked-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Some eMMC and SD cards implement a DSR register that allows to tune
raise/fall times and drive strength of the CMD and DATA outputs.
The values to use depend on the card in use and the host.
It might be needed to reduce the drive strength to prevent voltage peaks
above the host's specification.
Implement a 'dsr' devicetree property that allows to specify the value
to set the DSR to. For non-dt setups the new members of mmc_host can be
set by board code.
This patch was initially authored by Sascha Hauer. It contains
improvements authored by Markus Niebel and Uwe Kleine-König.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Markus Niebel <Markus.Niebel@tq-group.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
eMMC card can support up to 7 physical partitions, including 2 boot,
1 RPMB and 4 GPs. Change MMC_NUM_PHY_PARTITION from 6 to 7, which is
the correct value.
Signed-off-by: Yi Sun <yi.y.sun@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch adds an include of linux/types.h to make sure bool is defined
before utilized in this header file.
Signed-off-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This patch fix spelling typo found in DocBook/kernel-api.xml.
It is because the file is generated from the source comments,
I have to fix the comments in source codes.
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Drivers supporting multiple clusters or multiple 'struct cpufreq_policy'
instances may need to keep per-policy data. If the core doesn't provide support
for that, they might do it in the most unoptimized way: 'per-cpu' data.
This patch adds another field in struct cpufreq_policy: 'driver_data'. It isn't
accessed by core and is for driver's internal use only.
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
John W. Linville says:
====================
pull request: wireless-next 2014-09-08
Please pull this batch of updates intended for the 3.18 stream...
For the mac80211 bits, Johannes says:
"Not that much content this time. Some RCU cleanups, crypto
performance improvements, and various patches all over,
rather than listing them one might as well look into the
git log instead."
For the Bluetooth bits, Gustavo says:
"The changes consists of:
- Coding style fixes to HCI drivers
- Corrupted ack value fix for the H5 HCI driver
- A couple of Enhanced L2CAP fixes
- Conversion of SMP code to use common L2CAP channel API
- Page scan optimizations when using the kernel-side whitelist
- Various mac802154 and and ieee802154 6lowpan cleanups
- One new Atheros USB ID"
For the iwlwifi bits, Emmanuel says:
"We have a new big thing coming up which is called Dynamic Queue
Allocation (or DQA). This is a completely new way to work with the
Tx queues and it requires major refactoring. This is being done by
Johannes and Avri. Besides this, Johannes disables U-APSD by default
because of APs that would disable A-MPDU if the association supports
U-ASPD. Luca contributed to the power area which he was cleaning
up on the way while working on CSA. A few more random things here
and there."
For the Atheros bits, Kalle says:
"For ath6kl we had two small fixes and a new SDIO device id.
For ath10k the bigger changes are:
* support for new firmware version 10.2 (Michal)
* spectral scan support (Simon, Sven & Mathias)
* export a firmware crash dump file (Ben & me)
* cleaning up of pci.c (Michal)
* print pci id in all messages, which causes most of the churn (Michal)"
Beyond that, we have the usual collection of various updates to ath9k,
b43, mwifiex, and wil6210, as well as a few other bits here and there.
Please let me know if there are problems!
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The OMAP version of the 8250 can actually use 1:1 serial8250_startup().
However it needs to be extended by a wake up irq which should to be
requested & enabled at ->startup() time and disabled at ->shutdown() time.
v2…v3: properly copy callbacks
v1…v2: add shutdown callback
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The flags field of struct uart_port can only be safely modified
if the port mutex is held; no other lock prevents concurrent
changes from corrupting the field.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is a pure code cleanup in the header file for the PM domain. No
functional change.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are currently no need to export default_stop_ok() as an API,
instead let's keep it local to the PM domain governor.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are no active users of this API. Let's remove it and if future
needs shows up we could consider to have a get/put API instead.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The pm_genpd_syscore_poweroff() API and pm_genpd_syscore_poweron() API
makes the pm_genpd_syscore_switch() API redundant.
Moreover, since there are no active users, let's just remove it.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The genpd dev_irq_safe configuration somewhat overlaps with the runtime
PM pm_runtime_irq_safe() option. Also, currently genpd don't have a
good way to deal with these device. So, until we figured out if and how
to support this in genpd, let's remove the option to configure it.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There no users of these callbacks, let's simplify the generic power
domain by removing them.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
In a step of simplifying the generic power domain let's move away from
using these callbacks.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are no users of these APIs. To simplify the generic power domain
let's remove them.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch allow the users of the 8250 infrastructure to define a
handler for RS485 configration.
If no handler is defined the 8250 driver will work as usual.
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Alan Cox <alan@linux.intel.com>
--
v2:Change suggested by Alan "One Thousand Gnomes":
- Move rs485 structure further down on the uart_8250_port structure
drivers/tty/serial/8250/8250_core.c | 39 +++++++++++++++++++++++++++++++++++++
include/linux/serial_8250.h | 3 +++
2 files changed, 42 insertions(+)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'v3.17-rc4' into next
Merge Linux 3.17-rc4 here so we have all the latest
fixes on next too. This also cleans up a few conflicts
when applying patches.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Conflicts:
drivers/usb/gadget/Makefile
drivers/usb/gadget/function/Makefile
drivers/usb/gadget/legacy/Makefile
drivers/usb/phy/phy-samsung-usb.h
A block_device may be attached to different gendisks and thus
different bdis over time. bdev_inode_switch_bdi() is used to switch
the associated bdi. The function assumes that the inode could be
dirty and transfers it between bdis if so. This is a bit nasty in
that it reaches into bdi internals.
This patch reimplements the function so that it writes out the inode
if dirty. This is a lot simpler and can be implemented without
exposing bdi internals.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@fb.com>
Two flags and one bdi_writeback field are no longer used. Remove
them.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
bdev_get_queue() returns the request_queue associated with the
specified block_device. blk_get_backing_dev_info() makes use of
bdev_get_queue() to determine the associated bdi given a block_device.
All the callers of bdev_get_queue() including
blk_get_backing_dev_info() assume that bdev_get_queue() may return
NULL and implement NULL handling; however, bdev_get_queue() requires
the passed in block_device is opened and attached to its gendisk.
Because an active gendisk always has a valid request_queue associated
with it, bdev_get_queue() can never return NULL and neither can
blk_get_backing_dev_info().
Make it clear that neither of the two functions can return NULL and
remove NULL handling from all the callers.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Chris Mason <clm@fb.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Move resource retrieval from atmel_tc_alloc to tc_probe to avoid lately
reporting resource related issues when a TC block user request a TC block.
Moreover, resources retrieval are usually done in the probe function,
thus moving them add some consistency with other drivers.
Initialization is done once, ie not every time a tc block is requested.
If it fails, the device is not appended to the list of tc blocks.
Furhermore, the device id is retrieved at probe as well, avoiding parsing
DT every time the user requests of tc block.
Signed-off-by: Gaël PORTAY <gael.portay@gmail.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Linux already supports 802.11h, where the access point can tell the
client to reduce its transmission power. However, 802.11h is only
defined for 5 GHz, where the need for this is much smaller than on
2.4 GHz.
Cisco has their own solution, called DTPC (Dynamic Transmit Power
Control). Cisco APs on a controller sometimes but not always send
802.11h; they always send DTPC, even on 2.4 GHz. This patch adds support
for parsing and honoring the DTPC IE in addition to the 802.11h
element (they do not always contain the same limits, so both must
be honored); the format is not documented, but very simple.
Tested (on top of wireless.git and on 3.16.1) against a Cisco Aironet
1142 joined to a Cisco 2504 WLC, by setting various transmit power
levels for the given access points and observing the results.
The Wireshark 802.11 dissector agrees with the interpretation of the
element, except for negative numbers, which seem to never happen
anyway.
Signed-off-by: Steinar H. Gunderson <sgunderson@bigfoot.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Add quirk to make sure that a device is always polled for input events
even if it hasn't been opened.
This is needed for devices that disconnects from the bus unless the
interrupt endpoint has been polled at least once or when not responding
to an input event (e.g. after having shut down X).
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Both times() and clock_gettime(CLOCK_PROCESS_CPUTIME_ID) have scalability
issues on large systems, due to both functions being serialized with a
lock.
The lock protects against reporting a wrong value, due to a thread in the
task group exiting, its statistics reporting up to the signal struct, and
that exited task's statistics being counted twice (or not at all).
Protecting that with a lock results in times() and clock_gettime() being
completely serialized on large systems.
This can be fixed by using a seqlock around the events that gather and
propagate statistics. As an additional benefit, the protection code can
be moved into thread_group_cputime(), slightly simplifying the calling
functions.
In the case of posix_cpu_clock_get_task() things can be simplified a
lot, because the calling function already ensures that the task sticks
around, and the rest is now taken care of in thread_group_cputime().
This way the statistics reporting code can run lockless.
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Daeseok Youn <daeseok.youn@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guillaume Morin <guillaume@morinfr.org>
Cc: Ionut Alexa <ionut.m.alexa@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Michal Schmidt <mschmidt@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: umgwanakikbuti@gmail.com
Cc: fweisbec@gmail.com
Cc: srao@redhat.com
Cc: lwoodman@redhat.com
Cc: atheurer@redhat.com
Link: http://lkml.kernel.org/r/20140816134010.26a9b572@annuminas.surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'v3.17-rc4' into sched/core, to prevent conflicts with upcoming patches, and to refresh the tree
Linux 3.17-rc4
Pull networking fixes from David Miller:
1) Fix skb leak in mac802154, from Martin Townsend
2) Use select not depends on NF_NAT for NFT_NAT, from Pablo Neira
Ayuso
3) Fix union initializer bogosity in vxlan, from Gerhard Stenzel
4) Fix RX checksum configuration in stmmac driver, from Giuseppe
CAVALLARO
5) Fix TSO with non-accelerated VLANs in e1000, e1000e, bna, ehea,
i40e, i40evf, mvneta, and qlge, from Vlad Yasevich
6) Fix capability checks in phy_init_eee(), from Giuseppe CAVALLARO
7) Try high order allocations more sanely for SKBs, specifically if a
high order allocation fails, fall back directly to zero order pages
rather than iterating down one order at a time. From Eric Dumazet
8) Fix a memory leak in openvswitch, from Li RongQing
9) amd-xgbe initializes wrong spinlock, from Thomas Lendacky
10) RTNL locking was busted in setsockopt for anycast and multicast, fix
from Sabrina Dubroca
11) Fix peer address refcount leak in ipv6, from Nicolas Dichtel
12) DocBook typo fixes, from Masanari Iida
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (101 commits)
ipv6: restore the behavior of ipv6_sock_ac_drop()
amd-xgbe: Enable interrupts for all management counters
amd-xgbe: Treat certain counter registers as 64 bit
greth: moved TX ring cleaning to NAPI rx poll func
cnic : Cleanup CONFIG_IPV6 & VLAN check
net: treewide: Fix typo found in DocBook/networking.xml
bnx2x: Fix link problems for 1G SFP RJ45 module
3c59x: avoid panic in boomerang_start_xmit when finding page address:
netfilter: add explicit Kconfig for NETFILTER_XT_NAT
ipv6: use addrconf_get_prefix_route() to remove peer addr
ipv6: fix a refcnt leak with peer addr
net-timestamp: only report sw timestamp if reporting bit is set
drivers/net/fddi/skfp/h/skfbi.h: Remove useless PCI_BASE_2ND macros
l2tp: fix race while getting PMTU on PPP pseudo-wire
ipv6: fix rtnl locking in setsockopt for anycast and multicast
VMXNET3: Check for map error in vmxnet3_set_mc
openvswitch: distinguish between the dropped and consumed skb
amd-xgbe: Fix initialization of the wrong spin lock
openvswitch: fix a memory leak
netfilter: fix missing dependencies in NETFILTER_XT_TARGET_LOG
...
Percpu allocator now supports allocation mask. Add @gfp to
percpu_ref_init() so that !GFP_KERNEL allocation masks can be used
with percpu_refs too.
This patch doesn't make any functional difference.
v2: blk-mq conversion was missing. Updated.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Nicholas A. Bellinger <nab@linux-iscsi.org>
Cc: Jens Axboe <axboe@kernel.dk>
Percpu allocator now supports allocation mask. Add @gfp to
[flex_]proportions init functions so that !GFP_KERNEL allocation masks
can be used with them too.
This patch doesn't make any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Peter Zijlstra <peterz@infradead.org>
Percpu allocator now supports allocation mask. Add @gfp to
percpu_counter_init() so that !GFP_KERNEL allocation masks can be used
with percpu_counters too.
We could have left percpu_counter_init() alone and added
percpu_counter_init_gfp(); however, the number of users isn't that
high and introducing _gfp variants to all percpu data structures would
be quite ugly, so let's just do the conversion. This is the one with
the most users. Other percpu data structures are a lot easier to
convert.
This patch doesn't make any functional difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: "David S. Miller" <davem@davemloft.net>
Cc: x86@kernel.org
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
The rcu_bh_qs(), rcu_preempt_qs(), and rcu_sched_qs() functions use
old-style per-CPU variable access and write to ->passed_quiesce even
if it is already set. This commit therefore updates to use the new-style
per-CPU variable access functions and avoids the spurious writes.
This commit also eliminates the "cpu" argument to these functions because
they are always invoked on the indicated CPU.
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The rcu_preempt_note_context_switch() function is on a scheduling fast
path, so it would be good to avoid disabling irqs. The reason that irqs
are disabled is to synchronize process-level and irq-handler access to
the task_struct ->rcu_read_unlock_special bitmask. This commit therefore
makes ->rcu_read_unlock_special instead be a union of bools with a short
allowing single-access checks in RCU's __rcu_read_unlock(). This results
in the process-level and irq-handler accesses being simple loads and
stores, so that irqs need no longer be disabled. This commit therefore
removes the irq disabling from rcu_preempt_note_context_switch().
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
In theory, synchronize_sched() requires a read-side critical section
to order against. In practice, preemption can be thought of as
being disabled across every machine instruction, at least for those
machine instructions that are not in the idle loop and not on offline
CPUs. So this commit removes the redundant preempt_disable() from
rcu_note_voluntary_context_switch().
Please note that the single instruction in question is the store of
zero to ->rcu_tasks_holdout. The "if" is simply a performance optimization
that avoids unnecessary stores. To see this, keep in mind that both
the "if" condition and the store are in a quiescent state. Therefore,
even if the task is preempted for a full grace period (presumably due
to its having done a context switch beforehand), the store will be
recording a legitimate quiescent state.
Reported-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Conflicts:
include/linux/rcupdate.h
Currently TASKS_RCU would ignore a CPU running a task in nohz_full=
usermode execution. There would be neither a context switch nor a
scheduling-clock interrupt to tell TASKS_RCU that the task in question
had passed through a quiescent state. The grace period would therefore
extend indefinitely. This commit therefore makes RCU's dyntick-idle
subsystem record the task_struct structure of the task that is running
in dyntick-idle mode on each CPU. The TASKS_RCU grace period can
then access this information and record a quiescent state on
behalf of any CPU running in dyntick-idle usermode.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit adds torture tests for RCU-tasks. It also fixes a bug that
would segfault for an RCU flavor lacking a callback-barrier function.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Once a task has passed exit_notify() in the do_exit() code path, it
is no longer on the task lists, and is therefore no longer visible
to rcu_tasks_kthread(). This means that an almost-exited task might
be preempted while within a trampoline, and this task won't be waited
on by rcu_tasks_kthread(). This commit fixes this bug by adding an
srcu_struct. An exiting task does srcu_read_lock() just before calling
exit_notify(), and does the corresponding srcu_read_unlock() after
doing the final preempt_disable(). This means that rcu_tasks_kthread()
can do synchronize_srcu() to wait for all mostly-exited tasks to reach
their final preempt_disable() region, and then use synchronize_sched()
to wait for those tasks to finish exiting.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
It turns out to be easier to add the synchronous grace-period waiting
functions to RCU-tasks than to work around their absense in rcutorture,
so this commit adds them. The key point is that the existence of
call_rcu_tasks() means that rcutorture needs an rcu_barrier_tasks().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
RCU-tasks requires the occasional voluntary context switch
from CPU-bound in-kernel tasks. In some cases, this requires
instrumenting cond_resched(). However, there is some reluctance
to countenance unconditionally instrumenting cond_resched() (see
http://lwn.net/Articles/603252/), so this commit creates a separate
cond_resched_rcu_qs() that may be used in place of cond_resched() in
locations prone to long-duration in-kernel looping.
This commit currently instruments only RCU-tasks. Future possibilities
include also instrumenting RCU, RCU-bh, and RCU-sched in order to reduce
IPI usage.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit adds a new RCU-tasks flavor of RCU, which provides
call_rcu_tasks(). This RCU flavor's quiescent states are voluntary
context switch (not preemption!) and userspace execution (not the idle
loop -- use some sort of schedule_on_each_cpu() if you need to handle the
idle tasks. Note that unlike other RCU flavors, these quiescent states
occur in tasks, not necessarily CPUs. Includes fixes from Steven Rostedt.
This RCU flavor is assumed to have very infrequent latency-tolerant
updaters. This assumption permits significant simplifications, including
a single global callback list protected by a single global lock, along
with a single task-private linked list containing all tasks that have not
yet passed through a quiescent state. If experience shows this assumption
to be incorrect, the required additional complexity will be added.
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
User pr_alert/pr_cont for printing the logs from rcutorture module directly
instead of writing it to a buffer and then printing it. This allows us from not
having to allocate such buffers. Also remove a resulting empty function.
I tested this using the parse-torture.sh script as follows:
$ dmesg | grep torture > log.txt
$ bash parse-torture.sh log.txt test
$
There were no warnings which means that parsing went fine.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit uninlines rcu_read_lock_held(). According to "size vmlinux"
this saves 28549 in .text:
- 5541731 3014560 14757888 23314179
+ 5513182 3026848 14757888 23297918
Note: it looks as if the data grows by 12288 bytes but this is not true,
it does not actually grow. But .data starts with ALIGN(THREAD_SIZE) and
since .text shrinks the padding grows, and thus .data grows too as it
seen by /bin/size. diff System.map:
- ffffffff81510000 D _sdata
- ffffffff81510000 D init_thread_union
+ ffffffff81509000 D _sdata
+ ffffffff8150c000 D init_thread_union
Perhaps we can change vmlinux.lds.S to .data itself, so that /bin/size
can't "wrongly" report that .data grows if .text shinks.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
