css_set_rwsem is the inner lock protecting css_sets and is accessed
from hot paths such as fork and exit. Internally, it has no reason to
be a rwsem or even mutex. There are no internal blocking operations
while holding it. This was rwsem because css task iteration used to
expose it to external iterator users. As the previous patch updated
css task iteration such that the locking is not leaked to its users,
there's no reason to keep it a rwsem.
This patch converts css_set_rwsem to a spinlock and rename it to
css_set_lock. It uses bh-safe operations as a planned usage needs to
access it from RCU callback context.
Signed-off-by: Tejun Heo <tj@kernel.org>
css_sets are synchronized through css_set_rwsem but the locking scheme
is kinda bizarre. The hot paths - fork and exit - have to write lock
the rwsem making the rw part pointless; furthermore, many readers
already hold cgroup_mutex.
One of the readers is css task iteration. It read locks the rwsem
over the entire duration of iteration. This leads to silly locking
behavior. When cpuset tries to migrate processes of a cgroup to a
different NUMA node, css_set_rwsem is held across the entire migration
attempt which can take a long time locking out forking, exiting and
other cgroup operations.
This patch updates css task iteration so that it locks css_set_rwsem
only while the iterator is being advanced. css task iteration
involves two levels - css_set and task iteration. As css_sets in use
are practically immutable, simply pinning the current one is enough
for resuming iteration afterwards. Task iteration is tricky as tasks
may leave their css_set while iteration is in progress. This is
solved by keeping track of active iterators and advancing them if
their next task leaves its css_set.
v2: put_task_struct() in css_task_iter_next() moved outside
css_set_rwsem. A later patch will add cgroup operations to
task_struct free path which may grab the same lock and this avoids
deadlock possibilities.
css_set_move_task() updated to use list_for_each_entry_safe() when
walking task_iters and advancing them. This is necessary as
advancing an iter may remove it from the list.
Signed-off-by: Tejun Heo <tj@kernel.org>
Currently, cgroup_has_tasks() tests whether the target cgroup has any
css_set linked to it. This works because a css_set's refcnt converges
with the number of tasks linked to it and thus there's no css_set
linked to a cgroup if it doesn't have any live tasks.
To help tracking resource usage of zombie tasks, putting the ref of
css_set will be separated from disassociating the task from the
css_set which means that a cgroup may have css_sets linked to it even
when it doesn't have any live tasks.
This patch replaces cgroup_has_tasks() with cgroup_is_populated()
which tests cgroup->nr_populated instead which locally counts the
number of populated css_sets. Unlike cgroup_has_tasks(),
cgroup_is_populated() is recursive - if any of the descendants is
populated, the cgroup is populated too. While this changes the
meaning of the test, all the existing users are okay with the change.
While at it, replace the open-coded ->populated_cnt test in
cgroup_events_show() with cgroup_is_populated().
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Currently, cgroup->nr_populated counts whether the cgroup has any
css_sets linked to it and the number of children which has non-zero
->nr_populated. This works because a css_set's refcnt converges with
the number of tasks linked to it and thus there's no css_set linked to
a cgroup if it doesn't have any live tasks.
To help tracking resource usage of zombie tasks, putting the ref of
css_set will be separated from disassociating the task from the
css_set which means that a cgroup may have css_sets linked to it even
when it doesn't have any live tasks.
This patch updates cgroup->nr_populated so that for the cgroup itself
it counts the number of css_sets which have tasks associated with them
so that empty css_sets don't skew the populated test.
Signed-off-by: Tejun Heo <tj@kernel.org>
Merge "Marvell Berlin BG2Q CPU clock driver" from Sebastian Hesselbarth:
- add BG2Q CPU clock to clk driver
* tag 'berlin-new-cpuclk-for-4.4-1' of git://git.infradead.org/users/hesselba/linux-berlin:
clk: berlin: add cpuclk
ARM: berlin: dts: add CLKID_CPU for BG2Q
Merge "Broadcom soc changes for v4.4 (try 2)" from Florian Fainelli:
This pull request contains the following Broadcom SoC platform and driver changes:
- Brian Norris create a drivers/soc/brcmstb/ stub as a place holder for SoC-specific
code which is coming next
- Florian Fainelli adds support for configuring the BCM7xxx SoCs Bus Interface Unit
with their specific write-pairing setting, which must be saved and restored during
system-wide suspend/resume, and consequently updates the brcmstb machine code to
initialize the BIU
- Jon Mason adds support for the Northstar Plus SoCs by introducing a custom machine
descriptor matching their compatible string and setting up the PL310 L2 cache and
enabling the relevant ARM errata for their Cortex-A9
* tag 'arm-soc/for-4.4/soc' of http://github.com/Broadcom/stblinux:
ARM: brcmstb: Setup BIU control registers during boot
soc: brcmstb: Add Bus Interface Unit control setup
soc: add stubs for brcmstb SoC's
ARM: NSP: Add basic support for Broadcom Northstar Plus SoC
It can be called by user space to CLONE two files.
Follow btrfs lead and define NFS_IOC_CLONE same as BTRFS_IOC_CLONE.
Thus we don't mess up userspace with too many ioctls.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Pull "Marvell Berlin DT CPU clock for 4.4" from Sebastian Hesselbarth:
- add missing CLKID_CPU for Berlin BG2Q
* tag 'berlin-dt-cpuclk-for-4.4-1' of git://git.infradead.org/users/hesselba/linux-berlin:
ARM: berlin: dts: add CLKID_CPU for BG2Q
bdi's are initialized in two steps, bdi_init() and bdi_register(), but
destroyed in a single step by bdi_destroy() which, for a bdi embedded
in a request_queue, is called during blk_cleanup_queue() which makes
the queue invisible and starts the draining of remaining usages.
A request_queue's user can access the congestion state of the embedded
bdi as long as it holds a reference to the queue. As such, it may
access the congested state of a queue which finished
blk_cleanup_queue() but hasn't reached blk_release_queue() yet.
Because the congested state was embedded in backing_dev_info which in
turn is embedded in request_queue, accessing the congested state after
bdi_destroy() was called was fine. The bdi was destroyed but the
memory region for the congested state remained accessible till the
queue got released.
a13f35e871 ("writeback: don't embed root bdi_writeback_congested in
bdi_writeback") changed the situation. Now, the root congested state
which is expected to be pinned while request_queue remains accessible
is separately reference counted and the base ref is put during
bdi_destroy(). This means that the root congested state may go away
prematurely while the queue is between bdi_dstroy() and
blk_cleanup_queue(), which was detected by Andrey's KASAN tests.
The root cause of this problem is that bdi doesn't distinguish the two
steps of destruction, unregistration and release, and now the root
congested state actually requires a separate release step. To fix the
issue, this patch separates out bdi_unregister() and bdi_exit() from
bdi_destroy(). bdi_unregister() is called from blk_cleanup_queue()
and bdi_exit() from blk_release_queue(). bdi_destroy() is now just a
simple wrapper calling the two steps back-to-back.
While at it, the prototype of bdi_destroy() is moved right below
bdi_setup_and_register() so that the counterpart operations are
located together.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: a13f35e871 ("writeback: don't embed root bdi_writeback_congested in bdi_writeback")
Cc: stable@vger.kernel.org # v4.2+
Reported-and-tested-by: Andrey Konovalov <andreyknvl@google.com>
Link: http://lkml.kernel.org/g/CAAeHK+zUJ74Zn17=rOyxacHU18SgCfC6bsYW=6kCY5GXJBwGfQ@mail.gmail.com
Reviewed-by: Jan Kara <jack@suse.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This is only usable for the static 1:1 mapping of physical memory.
Any access to vmalloc or module regions will require some way of doing
an IOTLB flush. It's theoretically possible to hook into the
tlb_flush_kernel_range() function, but that seems like overkill — most
of the addresses accessed through a kernel PASID *will* be in the 1:1
mapping.
If we really need to allow access to more interesting kernel regions,
then the answer will probably be an explicit IOTLB flush call after use,
akin to the DMA API's unmap function.
In fact, it might be worth introducing that sooner rather than later, and
making it just BUG() if the address isn't in the static 1:1 mapping.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Taking inspiration from the existing arch/arm code, break out some
generic functions to interface the DMA-API to the IOMMU-API. This will
do the bulk of the heavy lifting for IOMMU-backed dma-mapping.
Since associating an IOVA allocator with an IOMMU domain is a fairly
common need, rather than introduce yet another private structure just to
do this for ourselves, extend the top-level struct iommu_domain with the
notion. A simple opaque cookie allows reuse by other IOMMU API users
with their various different incompatible allocator types.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Change the journal's checksum functions to gate on whether or not the
crc32c driver is loaded, and gate the loading on the superblock bits.
This prevents a journal crash if someone loads a journal in no-csum
mode and then randomizes the superblock, thus flipping on the feature
bits.
Tested-By: Nikolay Borisov <kernel@kyup.com>
Reported-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Similar to the attr usecase, the caller knows if he is holding RTNL and is
in atomic section. So let the called to decide the correct call variant.
This allows drivers to sleep inside their ops and wait for hw to get the
operation status. Then the status is propagated into switchdev core.
This avoids silent errors in drivers.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When object is used in deferred work, we cannot use pointers in
switchdev object structures because the memory they point at may be already
used by someone else. So rather do local copy of the value.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Scott Feldman <sfeldma@gmail.com>
Reviewed-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Caller should know if he can call attr_set directly (when holding RTNL)
or if he has to defer the att_set processing for later.
This also allows drivers to sleep inside attr_set and report operation
status back to switchdev core. Switchdev core then warns if status is
not ok, instead of silent errors happening in drivers.
Benefit from newly introduced switchdev deferred ops infrastructure.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce infrastructure which will be used internally to defer ops.
Note that the deferred ops are queued up and either are processed by
scheduled work or explicitly by user calling deferred_process function.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A few multiple codec drivers do renaming the chip_name string but all
these are open-coded and some of them have even no error check. Let's
make common helpers to do it properly.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This provides basic PASID support for endpoint devices, tested with a
version of the i915 driver.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
As long as we use an identity mapping to work around the worst of the
hardware bugs which caused us to defeature it and change the definition
of the capability bit, we *can* use PASID support on the devices which
advertised it in bit 28 of the Extended Capability Register.
Allow people to do so with 'intel_iommu=pasid28' on the command line.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
It was found while running a database workload on large systems that
significant time was spent trying to acquire the sighand lock.
The issue was that whenever an itimer expired, many threads ended up
simultaneously trying to send the signal. Most of the time, nothing
happened after acquiring the sighand lock because another thread
had just already sent the signal and updated the "next expire" time.
The fastpath_timer_check() didn't help much since the "next expire"
time was updated after the threads exit fastpath_timer_check().
This patch addresses this by having the thread_group_cputimer structure
maintain a boolean to signify when a thread in the group is already
checking for process wide timers, and adds extra logic in the fastpath
to check the boolean.
Signed-off-by: Jason Low <jason.low2@hp.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: George Spelvin <linux@horizon.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: hideaki.kimura@hpe.com
Cc: terry.rudd@hpe.com
Cc: scott.norton@hpe.com
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1444849677-29330-5-git-send-email-jason.low2@hp.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Kernel headers should use linux/types.h based definitions.
Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Fixes userspace compilation error:
error: expected specifier-qualifier-list before ‘DECLARE_BITMAP’
DECLARE_BITMAP(gpr_valid, 0x200); /* bitmask of valid initializers */
DECLARE_BITMAP macro is not meant for userspace headers and thus
added here as private copy for emu10k.h.
Fix was suggested by Arnd Bergmann <arnd@arndb.de> in message
<2168807.4Yxh5gl11Q@wuerfel> and Takashi Iwai <tiwai@suse.de>
in message <s5h1thx88tk.wl-tiwai@suse.de> on lkml.
Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
By design, when no default MAC addresses are set in the Hypervisor for VFs,
the VFs are passed zero-macs. When such a MAC is received by the VF, it
generates a random MAC address and registers that MAC address
with the Hypervisor.
This random mac generation is currently done in the mlx4_en module.
There is a problem, though, if the mlx4_ib module is loaded by a VF before
the mlx4_en module. In this case, for RoCE, mlx4_ib will see the un-replaced
zero-mac and register that zero-mac as part of QP1 initialization.
Having a zero-mac in the port's MAC table creates problems for a
Baseboard Management Console. The BMC occasionally sends packets with a
zero-mac destination MAC. If there is a zero-mac present in the port's
MAC table, the FW will send such BMC packets to the host driver rather than
to the wire, and BMC will stop working.
To address this problem, we move the replacement of zero-mac addresses
with random-mac addresses to procedure mlx4_slave_cap(), which is part of the
driver startup for VFs, and is before activation of mlx4_ib and mlx4_en.
As a result, zero-mac addresses will never be registered in the port MAC table
by the driver.
In addition, when mlx4_en does initialize the net device, it needs to set
the NET_ADDR_RANDOM flag in the netdev structure if the address was
randomly generated. This is done so that udev on the VM does not create
a new device name after each VF probe (VM boot and such). To accomplish this,
we add a per-port flag in mlx4_dev which gets set whenever mlx4_core replaces
a zero-mac with a randomly-generated mac. This flag is examined when mlx4_en
initializes the net-device.
Fix was suggested by Matan Barak <matanb@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On device initialization, wait till firmware indicates that that it is done
with initialization before proceeding to initialize the device.
Also update initialization segment layout to match driver/firmware
interface definitions.
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch implement the pci_error_handlers for mlx5_core which allow the
driver to recover from PCI error.
Once an error is detected in the PCI, the mlx5_pci_err_detected is called
and it:
1) Marks the device to be in 'Internal Error' state.
2) Dispatches an event to the mlx5_ib to flush all the outstanding cqes
with error.
3) Returns all the on going commands with error.
4) Unloads the driver.
Afterwards, the FW is reset and mlx5_pci_slot_reset is called and it
enables the device and restore it's pci state.
If the later succeeds, mlx5_pci_resume is called, and it loads the SW
stack.
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The detection of a fatal condition has been updated to take into account
the state reported by the device or by detecting an all ones read of the
firmware version which indicates that the device is not accessible.
Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
At listen() time, there is a small window where listener is visible with
a zero backlog, triggering a spurious "Possible SYN flooding on port"
message.
Nothing prevents us from setting the correct backlog.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Marc Kleine-Budde says:
====================
pull-request: can-next 2015-09-17
this is a pull request of 4 patches for net-next/master.
Two patches are by Gerhard Bertelsmann, fixing some problems in the
sun4i driver. The patch by Arnd Bergmann stops using timeval for the
CAN broadcast manager. The last patch by Alexandre Belloni removes the
otherwise unused struct at91_can_data from the driver.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
ACPI subtable parsing needs to be extended to allow two or more
handlers to be run in the same ACPI table walk, thus adding
acpi_subtable_proc structure which stores
() ACPI table id
() handler that processes table
() counter how many items has been processed
and passing it to acpi_parse_entries_array() and
acpi_table_parse_entries_array().
This is needed to fix CPU enumeration when APIC/X2APIC entries
are interleaved.
Signed-off-by: Lukasz Anaczkowski <lukasz.anaczkowski@intel.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This zeroes the msg so no random stack data ends up getting
sent, it also limits the function to not accepting > 4
i2c msgs.
Cc: stable@vger.kernel.org
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This gives us a function for making mailbox property channel requests
of the firmware, which is most notable in that it will let us get and
set clock rates.
Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
This change is similar to e001bbae71
ARM: cmpxchg: avoid warnings from macro-ized cmpxchg() implementations
A recent change in kernel/acct.c added a new warning for many
configurations using generic __xchg() implementation:
In file included from ./arch/nios2/include/asm/cmpxchg.h:12:0,
from include/asm-generic/atomic.h:18,
from arch/nios2/include/generated/asm/atomic.h:1,
from include/linux/atomic.h:4,
from include/linux/spinlock.h:406,
from include/linux/mmzone.h:7,
from include/linux/gfp.h:5,
from include/linux/mm.h:9,
from kernel/acct.c:46:
kernel/acct.c: In function 'acct_pin_kill':
include/asm-generic/cmpxchg.h:94:3: warning: value computed is not used [-Wunused-value]
((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
^
include/asm-generic/cmpxchg.h:102:28: note: in expansion of macro 'cmpxchg_local'
#define cmpxchg(ptr, o, n) cmpxchg_local((ptr), (o), (n))
^
kernel/acct.c:177:2: note: in expansion of macro 'cmpxchg'
cmpxchg(&acct->ns->bacct, pin, NULL);
^
The code is in fact correct, it's just a cmpxchg() call that
intentionally ignores the result, and no other code does that. The
warning does not show up on x86 because of the way that its cmpxchg()
macro is written. This changes the asm-ggeneric implementation to use
a similar construct with a compound expression instead of a typecast,
which causes the compiler to not complain about an unused result.
Fix the other macros in this file in a similar way, and place them
just below their function implementations.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
This header contains a few helpers currenly only used by the mpi
implementation, and not default implementation of architecture code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
These are not implementations of default architecture code but helpers
for drivers. Move them to the place they belong to.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Acked-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Passing a void ** almost always requires a cast at the call site.
Instead of littering the code with casts every time this function
is called, have qcom_smem_get() return a void pointer to the
location of the smem item. This frees the caller from having to
cast the pointer.
Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Andy Gross <agross@codeaurora.org>
Implement a id_table based driver maching mechanism for drivers that
binds to fixed channels and doesn't need any additional configuration,
e.g. IPCRTR and DIAG.
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Signed-off-by: Andy Gross <agross@codeaurora.org>
