alloc_workqueue() currently expects the passed in @name pointer to remain
accessible. This is inconvenient and a bit silly given that the whole wq
is being dynamically allocated. This patch updates alloc_workqueue() and
friends to take printf format string instead of opaque string and matching
varargs at the end. The name is allocated together with the wq and
formatted.
alloc_ordered_workqueue() is converted to a macro to unify varargs
handling with alloc_workqueue(), and, while at it, add comment to
alloc_workqueue().
None of the current in-kernel users pass in string with '%' as constant
name and this change shouldn't cause any problem.
[akpm@linux-foundation.org: use __printf]
Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are users which want to drain workqueues without destroying it.
Separate out drain functionality from destroy_workqueue() into
drain_workqueue() and make it accessible to workqueue users.
To guarantee forward-progress, only chain queueing is allowed while
drain is in progress. If a new work item which isn't chained from the
running or pending work items is queued while draining is in progress,
WARN_ON_ONCE() is triggered.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
cancel_rearming_delayed_work() and cancel_rearming_delayed_workqueue()
can be removed now.
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
wq:fixes-2.6.38 does s/WQ_FREEZEABLE/WQ_FREEZABLE and wq:for-2.6.39
adds new usage of the flag. The combination of the two creates a
build failure after merge. Fix it by renaming all freezeables to
freezables.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
There are two spellings in use for 'freeze' + 'able' - 'freezable' and
'freezeable'. The former is the more prominent one. The latter is
mostly used by workqueue and in a few other odd places. Unify the
spelling to 'freezable'.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Steven Whitehouse <swhiteho@redhat.com>
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (33 commits)
usb: don't use flush_scheduled_work()
speedtch: don't abuse struct delayed_work
media/video: don't use flush_scheduled_work()
media/video: explicitly flush request_module work
ioc4: use static work_struct for ioc4_load_modules()
init: don't call flush_scheduled_work() from do_initcalls()
s390: don't use flush_scheduled_work()
rtc: don't use flush_scheduled_work()
mmc: update workqueue usages
mfd: update workqueue usages
dvb: don't use flush_scheduled_work()
leds-wm8350: don't use flush_scheduled_work()
mISDN: don't use flush_scheduled_work()
macintosh/ams: don't use flush_scheduled_work()
vmwgfx: don't use flush_scheduled_work()
tpm: don't use flush_scheduled_work()
sonypi: don't use flush_scheduled_work()
hvsi: don't use flush_scheduled_work()
xen: don't use flush_scheduled_work()
gdrom: don't use flush_scheduled_work()
...
Fixed up trivial conflict in drivers/media/video/bt8xx/bttv-input.c
as per Tejun.
* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
MAINTAINERS: Update timer related entries
timers: Use this_cpu_read
timerqueue: Make timerqueue_getnext() static inline
hrtimer: fix timerqueue conversion flub
hrtimers: Convert hrtimers to use timerlist infrastructure
timers: Fixup allmodconfig build issue
timers: Rename timerlist infrastructure to timerqueue
timers: Introduce timerlist infrastructure.
hrtimer: Remove stale comment on curr_timer
timer: Warn when del_timer_sync() is called in hardirq context
timer: Del_timer_sync() can be used in softirq context
timer: Make try_to_del_timer_sync() the same on SMP and UP
posix-timers: Annotate lock_timer()
timer: Permit statically-declared work with deferrable timers
time: Use ARRAY_SIZE macro in timecompare.c
timer: Initialize the field slack of timer_list
timer_list: Remove alignment padding on 64 bit when CONFIG_TIMER_STATS
time: Compensate for rounding on odd-frequency clocksources
Fix up trivial conflict in MAINTAINERS
There's no in-kernel user left for these two obsolete functions. Mark
them deprecated and schedule for removal during 2.6.39 cycle.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Silly though it is, completions and wait_queue_heads use foo_ONSTACK
(COMPLETION_INITIALIZER_ONSTACK, DECLARE_COMPLETION_ONSTACK,
__WAIT_QUEUE_HEAD_INIT_ONSTACK and DECLARE_WAIT_QUEUE_HEAD_ONSTACK) so I
guess workqueues should do the same thing.
s/INIT_WORK_ON_STACK/INIT_WORK_ONSTACK/
s/INIT_DELAYED_WORK_ON_STACK/INIT_DELAYED_WORK_ONSTACK/
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, you have to just define a delayed_work uninitialised, and then
initialise it before first use. That's a tad clumsy. At risk of playing
mind-games with the compiler, fooling it into doing pointer arithmetic
with compile-time-constants, this lets clients properly initialise delayed
work with deferrable timers statically.
This patch was inspired by the issues which lead Artem Bityutskiy to
commit 8eab945c56 ("sunrpc: make the cache cleaner workqueue
deferrable").
Signed-off-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Acked-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Commit a25909a4 (lockdep: Add an in_workqueue_context() lockdep-based
test function) added in_workqueue_context() but there hasn't been any
in-kernel user and the lockdep annotation in workqueue is scheduled to
change. Remove the unused function.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Add WQ_MEM_RECLAIM flag which currently maps to WQ_RESCUER, mark
WQ_RESCUER as internal and replace all external WQ_RESCUER usages to
WQ_MEM_RECLAIM.
This makes the API users express the intent of the workqueue instead
of indicating the internal mechanism used to guarantee forward
progress. This is also to make it cleaner to add more semantics to
WQ_MEM_RECLAIM. For example, if deemed necessary, memory reclaim
workqueues can be made highpri.
This patch doesn't introduce any functional change.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Implement flush[_delayed]_work_sync(). These are flush functions
which also make sure no CPU is still executing the target work from
earlier queueing instances. These are similar to
cancel[_delayed]_work_sync() except that the target work item is
flushed instead of cancelled.
Signed-off-by: Tejun Heo <tj@kernel.org>
Make the following cleanup changes.
* Relocate flush/cancel function prototypes and definitions.
* Relocate wait_on_cpu_work() and wait_on_work() before
try_to_grab_pending(). These will be used to implement
flush_work_sync().
* Make all flush/cancel functions return bool instead of int.
* Update wait_on_cpu_work() and wait_on_work() to return %true if they
actually waited.
* Add / update comments.
This patch doesn't cause any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
alloc_ordered_workqueue() creates a workqueue which processes each
work itemp one by one in the queued order. This will be used to
replace create_freezeable_workqueue() and
create_singlethread_workqueue().
Signed-off-by: Tejun Heo <tj@kernel.org>
cwq->nr_active is used to keep track of how many work items are active
for the cpu workqueue, where 'active' is defined as either pending on
global worklist or executing. This is used to implement the
max_active limit and workqueue freezing. If a work item is queued
after nr_active has already reached max_active, the work item doesn't
increment nr_active and is put on the delayed queue and gets activated
later as previous active work items retire.
try_to_grab_pending() which is used in the cancellation path
unconditionally decremented nr_active whether the work item being
cancelled is currently active or delayed, so cancelling a delayed work
item makes nr_active underflow. This breaks max_active enforcement
and triggers BUG_ON() in destroy_workqueue() later on.
This patch fixes this bug by adding a flag WORK_STRUCT_DELAYED, which
is set while a work item in on the delayed list and making
try_to_grab_pending() decrement nr_active iff the work item is
currently active.
The addition of the flag enlarges cwq alignment to 256 bytes which is
getting a bit too large. It's scheduled to be reduced back to 128
bytes by merging WORK_STRUCT_PENDING and WORK_STRUCT_CWQ in the next
devel cycle.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Now that the worklist is global, having works pending after wq
destruction can easily lead to oops and destroy_workqueue() have
several BUG_ON()s to catch these cases. Unfortunately, BUG_ON()
doesn't tell much about how the work became pending after the final
flush_workqueue().
This patch adds WQ_DYING which is set before the final flush begins.
If a work is requested to be queued on a dying workqueue,
WARN_ON_ONCE() is triggered and the request is ignored. This clearly
indicates which caller is trying to queue a work on a dying workqueue
and keeps the system working in most cases.
Locking rule comment is updated such that the 'I' rule includes
modifying the field from destruction path.
Signed-off-by: Tejun Heo <tj@kernel.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (55 commits)
workqueue: mark init_workqueues() as early_initcall()
workqueue: explain for_each_*cwq_cpu() iterators
fscache: fix build on !CONFIG_SYSCTL
slow-work: kill it
gfs2: use workqueue instead of slow-work
drm: use workqueue instead of slow-work
cifs: use workqueue instead of slow-work
fscache: drop references to slow-work
fscache: convert operation to use workqueue instead of slow-work
fscache: convert object to use workqueue instead of slow-work
workqueue: fix how cpu number is stored in work->data
workqueue: fix mayday_mask handling on UP
workqueue: fix build problem on !CONFIG_SMP
workqueue: fix locking in retry path of maybe_create_worker()
async: use workqueue for worker pool
workqueue: remove WQ_SINGLE_CPU and use WQ_UNBOUND instead
workqueue: implement unbound workqueue
workqueue: prepare for WQ_UNBOUND implementation
libata: take advantage of cmwq and remove concurrency limitations
workqueue: fix worker management invocation without pending works
...
Fixed up conflicts in fs/cifs/* as per Tejun. Other trivial conflicts in
include/linux/workqueue.h, kernel/trace/Kconfig and kernel/workqueue.c
Mark init_workqueues() as early_initcall() and thus it will be initialized
before smp bringup. init_workqueues() registers for the hotcpu notifier
and thus it should cope with the processors that are brought online after
the workqueues are initialized.
x86 smp bringup code uses workqueues and uses a workaround for the
cold boot process (as the workqueues are initialized post smp_init()).
Marking init_workqueues() as early_initcall() will pave the way for
cleaning up this code.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Once a work starts execution, its data contains the cpu number it was
on instead of pointing to cwq. This is added by commit 7a22ad75
(workqueue: carry cpu number in work data once execution starts) to
reliably determine the work was last on even if the workqueue itself
was destroyed inbetween.
Whether data points to a cwq or contains a cpu number was
distinguished by comparing the value against PAGE_OFFSET. The
assumption was that a cpu number should be below PAGE_OFFSET while a
pointer to cwq should be above it. However, on architectures which
use separate address spaces for user and kernel spaces, this doesn't
hold as PAGE_OFFSET is zero.
Fix it by using an explicit flag, WORK_STRUCT_CWQ, to mark what the
data field contains. If the flag is set, it's pointing to a cwq;
otherwise, it contains a cpu number.
Reported on s390 and microblaze during linux-next testing.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Sachin Sant <sachinp@in.ibm.com>
Reported-by: Michal Simek <michal.simek@petalogix.com>
Reported-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Tested-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Tested-by: Michal Simek <monstr@monstr.eu>
WQ_SINGLE_CPU combined with @max_active of 1 is used to achieve full
ordering among works queued to a workqueue. The same can be achieved
using WQ_UNBOUND as unbound workqueues always use the gcwq for
WORK_CPU_UNBOUND. As @max_active is always one and benefits from cpu
locality isn't accessible anyway, serving them with unbound workqueues
should be fine.
Drop WQ_SINGLE_CPU support and use WQ_UNBOUND instead. Note that most
single thread workqueue users will be converted to use multithread or
non-reentrant instead and only the ones which require strict ordering
will keep using WQ_UNBOUND + @max_active of 1.
Signed-off-by: Tejun Heo <tj@kernel.org>
