Pull workqueue updates from Tejun Heo:
"A lot of activities on workqueue side this time. The changes achieve
the followings.
- WQ_UNBOUND workqueues - the workqueues which are per-cpu - are
updated to be able to interface with multiple backend worker pools.
This involved a lot of churning but the end result seems actually
neater as unbound workqueues are now a lot closer to per-cpu ones.
- The ability to interface with multiple backend worker pools are
used to implement unbound workqueues with custom attributes.
Currently the supported attributes are the nice level and CPU
affinity. It may be expanded to include cgroup association in
future. The attributes can be specified either by calling
apply_workqueue_attrs() or through /sys/bus/workqueue/WQ_NAME/* if
the workqueue in question is exported through sysfs.
The backend worker pools are keyed by the actual attributes and
shared by any workqueues which share the same attributes. When
attributes of a workqueue are changed, the workqueue binds to the
worker pool with the specified attributes while leaving the work
items which are already executing in its previous worker pools
alone.
This allows converting custom worker pool implementations which
want worker attribute tuning to use workqueues. The writeback pool
is already converted in block tree and there are a couple others
are likely to follow including btrfs io workers.
- WQ_UNBOUND's ability to bind to multiple worker pools is also used
to make it NUMA-aware. Because there's no association between work
item issuer and the specific worker assigned to execute it, before
this change, using unbound workqueue led to unnecessary cross-node
bouncing and it couldn't be helped by autonuma as it requires tasks
to have implicit node affinity and workers are assigned randomly.
After these changes, an unbound workqueue now binds to multiple
NUMA-affine worker pools so that queued work items are executed in
the same node. This is turned on by default but can be disabled
system-wide or for individual workqueues.
Crypto was requesting NUMA affinity as encrypting data across
different nodes can contribute noticeable overhead and doing it
per-cpu was too limiting for certain cases and IO throughput could
be bottlenecked by one CPU being fully occupied while others have
idle cycles.
While the new features required a lot of changes including
restructuring locking, it didn't complicate the execution paths much.
The unbound workqueue handling is now closer to per-cpu ones and the
new features are implemented by simply associating a workqueue with
different sets of backend worker pools without changing queue,
execution or flush paths.
As such, even though the amount of change is very high, I feel
relatively safe in that it isn't likely to cause subtle issues with
basic correctness of work item execution and handling. If something
is wrong, it's likely to show up as being associated with worker pools
with the wrong attributes or OOPS while workqueue attributes are being
changed or during CPU hotplug.
While this creates more backend worker pools, it doesn't add too many
more workers unless, of course, there are many workqueues with unique
combinations of attributes. Assuming everything else is the same,
NUMA awareness costs an extra worker pool per NUMA node with online
CPUs.
There are also a couple things which are being routed outside the
workqueue tree.
- block tree pulled in workqueue for-3.10 so that writeback worker
pool can be converted to unbound workqueue with sysfs control
exposed. This simplifies the code, makes writeback workers
NUMA-aware and allows tuning nice level and CPU affinity via sysfs.
- The conversion to workqueue means that there's no 1:1 association
between a specific worker, which makes writeback folks unhappy as
they want to be able to tell which filesystem caused a problem from
backtrace on systems with many filesystems mounted. This is
resolved by allowing work items to set debug info string which is
printed when the task is dumped. As this change involves unifying
implementations of dump_stack() and friends in arch codes, it's
being routed through Andrew's -mm tree."
* 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (84 commits)
workqueue: use kmem_cache_free() instead of kfree()
workqueue: avoid false negative WARN_ON() in destroy_workqueue()
workqueue: update sysfs interface to reflect NUMA awareness and a kernel param to disable NUMA affinity
workqueue: implement NUMA affinity for unbound workqueues
workqueue: introduce put_pwq_unlocked()
workqueue: introduce numa_pwq_tbl_install()
workqueue: use NUMA-aware allocation for pool_workqueues
workqueue: break init_and_link_pwq() into two functions and introduce alloc_unbound_pwq()
workqueue: map an unbound workqueues to multiple per-node pool_workqueues
workqueue: move hot fields of workqueue_struct to the end
workqueue: make workqueue->name[] fixed len
workqueue: add workqueue->unbound_attrs
workqueue: determine NUMA node of workers accourding to the allowed cpumask
workqueue: drop 'H' from kworker names of unbound worker pools
workqueue: add wq_numa_tbl_len and wq_numa_possible_cpumask[]
workqueue: move pwq_pool_locking outside of get/put_unbound_pool()
workqueue: fix memory leak in apply_workqueue_attrs()
workqueue: fix unbound workqueue attrs hashing / comparison
workqueue: fix race condition in unbound workqueue free path
workqueue: remove pwq_lock which is no longer used
...
Now that devtmpfs is caring about uid/gid, we need to use the correct
internal types so users who have USER_NS enabled will have things work
properly for them.
Thanks to Eric for pointing this out, and the patch review.
Reported-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kay Sievers <kay@vrfy.org>
Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some drivers want to tell userspace what uid and gid should be used for
their device nodes, so allow that information to percolate through the
driver core to userspace in order to make this happen. This means that
some systems (i.e. Android and friends) will not need to even run a
udev-like daemon for their device node manager and can just rely in
devtmpfs fully, reducing their footprint even more.
Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Whenever a struct device_attribute is registered
with mismatched permissions - read permission without
a show routine or write permission without store
routine - we will issue a big warning so we catch
those early enough.
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Kay tells me the most appropriate place to expose workqueues to
userland would be /sys/devices/virtual/workqueues/WQ_NAME which is
symlinked to /sys/bus/workqueue/devices/WQ_NAME and that we're lacking
a way to do that outside of driver core as virtual_device_parent()
isn't exported and there's no inteface to conveniently create a
virtual subsystem.
This patch implements subsys_virtual_register() by factoring out
subsys_register() from subsys_system_register() and using it with
virtual_device_parent() as the origin directory. It's identical to
subsys_system_register() other than the origin directory but we aren't
gonna restrict the device names which should be used under it.
This will be used to expose workqueue attributes to userland.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
All in-kernel users of class_find_device() don't really need mutable
data for match callback.
In two places (kernel/power/suspend_test.c, drivers/scsi/osd/osd_uld.c)
this patch changes match callbacks to use const search data.
The const is propagated to rtc_class_open() and power_supply_get_by_name()
parameters.
Note that there's a dev reference leak in suspend_test.c that's not
touched in this patch.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the new vsprintf extension to avoid any possible
message interleaving.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
old_class_name, and new_class_name are never used. This patch remove the
declaration and calls to kfree.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@r1 forall@
type T; identifier i;
@@
* T *i = NULL;
... when != i
* kfree(i);
// </smpl>
Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull x86 RAS update from Ingo Molnar:
"Rework all config variables used throughout the MCA code and collect
them together into a mca_config struct. This keeps them tightly and
neatly packed together instead of spilled all over the place.
Then, convert those which are used as booleans into real booleans and
save some space. These bits are exposed via
/sys/devices/system/machinecheck/machinecheck*/"
* 'x86-ras-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, MCA: Finish mca_config conversion
x86, MCA: Convert the next three variables batch
x86, MCA: Convert rip_msr, mce_bootlog, monarch_timeout
x86, MCA: Convert dont_log_ce, banks and tolerant
drivers/base: Add a DEVICE_BOOL_ATTR macro
Pull driver core updates from Greg Kroah-Hartman:
"Here's the large driver core updates for 3.8-rc1.
The biggest thing here is the various __dev* marking removals. This
is going to be a pain for the merge with different subsystem trees, I
know, but all of the patches included here have been ACKed by their
various subsystem maintainers, as they wanted them to go through here.
If this is too much of a pain, I can pull all of them out of this tree
and just send you one with the other fixes/updates and then, after
3.8-rc1 is out, do the rest of the removals to ensure we catch them
all, it's up to you. The merges should all be trivial, and Stephen
has been doing them all in linux-next for a few weeks now quite
easily.
Other than the __dev* marking removals, there's nothing major here,
some firmware loading updates and other minor things in the driver
core.
All of these have (much to Stephen's annoyance), been in linux-next
for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
Fixed up trivial conflicts in drivers/gpio/gpio-{em,stmpe}.c due to gpio
update.
* tag 'driver-core-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (93 commits)
modpost.c: Stop checking __dev* section mismatches
init.h: Remove __dev* sections from the kernel
acpi: remove use of __devinit
PCI: Remove __dev* markings
PCI: Always build setup-bus when PCI is enabled
PCI: Move pci_uevent into pci-driver.c
PCI: Remove CONFIG_HOTPLUG ifdefs
unicore32/PCI: Remove CONFIG_HOTPLUG ifdefs
sh/PCI: Remove CONFIG_HOTPLUG ifdefs
powerpc/PCI: Remove CONFIG_HOTPLUG ifdefs
mips/PCI: Remove CONFIG_HOTPLUG ifdefs
microblaze/PCI: Remove CONFIG_HOTPLUG ifdefs
dma: remove use of __devinit
dma: remove use of __devexit_p
firewire: remove use of __devinitdata
firewire: remove use of __devinit
leds: remove use of __devexit
leds: remove use of __devinit
leds: remove use of __devexit_p
mmc: remove use of __devexit
...
syscore_shutdown uses initcall_debug to control the debug info output.
It’s a good programming. But device_shutdown doesn’t. The patch changes
device_shutdown to follow the style.
Signed-off-by: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We hit an hang issue when removing a mmc device on Medfield Android phone by sysfs interface.
device_pm_remove will call pm_runtime_remove which would disable
runtime PM of the device. After that pm_runtime_get* or
pm_runtime_put* will be ignored. So if we disable the runtime PM
before device really be removed, drivers' _remove callback may
access HW even pm_runtime_get* fails. That is bad.
Consider below call sequence when removing a device:
device_del => device_pm_remove
=> class_intf->remove_dev(dev, class_intf) => pm_runtime_get_sync/put_sync
=> bus_remove_device => device_release_driver => pm_runtime_get_sync/put_sync
remove_dev might call pm_runtime_get_sync/put_sync.
Then, generic device_release_driver also calls pm_runtime_get_sync/put_sync.
Since device_del => device_pm_remove firstly, later _get_sync wouldn't really wake up the device.
I git log -p to find the patch which moves the calling to device_pm_remove ahead.
It's below patch:
commit 775b64d2b6
Author: Rafael J. Wysocki <rjw@sisk.pl>
Date: Sat Jan 12 20:40:46 2008 +0100
PM: Acquire device locks on suspend
This patch reorganizes the way suspend and resume notifications are
sent to drivers. The major changes are that now the PM core acquires
every device semaphore before calling the methods, and calls to
device_add() during suspends will fail, while calls to device_del()
during suspends will block.
It also provides a way to safely remove a suspended device with the
help of the PM core, by using the device_pm_schedule_removal() callback
introduced specifically for this purpose, and updates two drivers (msr
and cpuid) that need to use it.
As device_pm_schedule_removal is deleted by another patch, we need also revert other parts of the patch,
i.e. move the calling of device_pm_remove after the calling to bus_remove_device.
Signed-off-by: LongX Zhang <longx.zhang@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
... which, analogous to DEVICE_INT_ATTR provides functionality to
set/clear bools. Its purpose is to be used where values need to be used
as booleans in configuration context.
Next patch uses this.
Signed-off-by: Borislav Petkov <bp@alien8.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Add utility functions to consolidate the use of
create_syslog_header and vprintk_emit.
This allows conversion of logging functions that
call create_syslog_header and then call vprintk_emit
or printk_emit to the dev_ equivalents.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c4e00daaa9
("driver-core: extend dev_printk() to pass structured data")
changed __dev_printk and broke dynamic-debug's ability to control the
dynamic prefix of dev_dbg(dev,..).
commit af7f2158fd
("drivers-core: make structured logging play nice with dynamic-debug")
made a minimal correction.
The current dynamic debug code uses up to 3 recursion levels via %pV.
This can consume quite a bit of stack. Directly call printk_emit to
reduce the recursion depth.
These changes include:
dev_dbg:
o Create and use function create_syslog_header to format the syslog
header for printk_emit uses.
o Call create_syslog_header and neaten __dev_printk
o Make __dev_printk static not global
o Remove include header declaration of __dev_printk
o Remove now unused EXPORT_SYMBOL() of __dev_printk
o Whitespace neatening
dynamic_dev_dbg:
o Remove KERN_DEBUG from dynamic_emit_prefix
o Call create_syslog_header and printk_emit
o Whitespace neatening
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
device_del can happen anytime, so once it happens,
the devres of the device will be freed inside device_del, but
drivers can't know it has been deleted and may still add
resources into the device, so memory leak is caused.
This patch moves the devres_release_all to fix the problem.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c4e00daaa9 changed __dev_printk
in a way that broke dynamic-debug's ability to control the dynamic
prefix of dev_dbg(dev,..), but not dev_dbg(NULL,..) or pr_debug(..),
which is why it wasnt noticed sooner.
When dev==NULL, __dev_printk() just calls printk(), which just works.
But otherwise, it assumed that level was always a string like "<L>"
and just plucked out the 'L', ignoring the rest. However,
dynamic_emit_prefix() adds "[tid] module:func:line:" to the string,
those additions all got lost.
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Cc: stable <stable@vger.kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Firstly, .shutdown callback may touch a uninitialized hardware
if dev->driver is set and .probe is not completed.
Secondly, device_shutdown() may dereference a null pointer to cause
oops when dev->driver is cleared after it has been checked in
device_shutdown().
So just hold device lock and its parent lock(if it has) to
fix the races.
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
