Commit Graph

26 Commits

Author SHA1 Message Date
Sam Leffler
52bc746a28 o enable shutdown of taskqueue threads; the thread servicing the queue checks
a new entry in the taskqueue struct each time it wakes up to see if it
  should terminate
o adjust TASKQUEUE_DEFINE_THREAD & co. to record the thread/proc identity for
  the shutdown rendezvous
o replace wakeup after adding a task to a queue with wakeup_one; this helps
  queues where multiple threads are used to service tasks (e.g. acpi)
o remove NULL check of tq_enqueue method; it should never be NULL

Reviewed by:	dfr, njl
2005-05-01 00:38:11 +00:00
Sam Leffler
f4581151a8 o eliminate modification of task structures after their run to avoid
modify-after-free races when the task structure is malloc'd
o shrink task structure by removing ta_flags (no longer needed with
  avoid fix) and combining ta_pending and ta_priority

Reviewed by:	dwhite, dfr
MFC after:	4 days
2005-04-24 16:52:45 +00:00
Warner Losh
14889b4229 Add taskqueue_drain. This waits for the specified task to finish, if
running, or returns.  The calling program is responsible for making sure
that nothing new is enqueued.

# man page coming soon.
2004-10-05 04:16:01 +00:00
John-Mark Gurney
227559d11f rearange some code that handles the thread taskqueue so that it is more
generic.  Introduce a new define TASKQUEUE_DEFINE_THREAD that takes a
single arg, which is the name of the queue.

Document these changes.
2004-08-08 02:37:22 +00:00
John Baldwin
bd83e879fd - Execute all of the tasks on the taskqueue during taskqueue_free() after
the queue has been removed from the global taskqueue_queues list.  This
  removes the need for the draining queue hack.
- Allow taskqueue_run() to be called with the taskqueue mutex held.  It
  can still be called without the lock for API compatiblity.  In that case
  it will acquire the lock internally.
- Don't lock the individual queue mutex in taskqueue_find() until after the
  strcmp as the global queues mutex is sufficient for the strcmp.
- Simplify taskqueue_thread_loop() now that it can hold the lock across
  taskqueue_run().

Submitted by:	bde (mostly)
2004-06-28 16:28:23 +00:00
John Baldwin
712f57d8ab Tidy up the thread taskqueue implementation and close a lost wakeup race.
Instead of creating a mutex that we msleep on but don't actually lock when
doing the corresponding wakeup(), in the kthread, lock the mutex associated
with our taskqueue and msleep while the queue is empty.  Assert that the
queue is locked when the callback function is called to wake the kthread.
2004-02-19 22:03:52 +00:00
John Baldwin
eb5b0e0565 Various style fixes.
Submitted by:	bde (mostly, if not all)
2003-12-17 21:13:04 +00:00
Alfred Perlstein
cd3c61b93d Fix a bug where the taskqueue kproc was being parented by init
because RFNOWAIT was being passed to kproc_create.

The result was that shutdown took quite a bit longer because this
errant "child" would not respond to termination signals from init
at system shutdown.

RFNOWAIT dissassociates itself from the caller by attaching to init
as a parent proc.  We could have had the taskqueue proc listen for
SIGKILL, but being able to SIGKILL a potentially critical system
process doesn't seem like a good idea.
2003-11-10 20:39:44 +00:00
Sam Leffler
7e2282a5a6 correct fast swi taskqueue spinlock name to be different from the sleep lock
Submitted by:	Tor Egge <Tor.Egge@cvsup.no.freebsd.org>
2003-09-06 21:05:18 +00:00
Sam Leffler
f82c9e70f9 "fast swi" taskqueue support. This is a taskqueue that uses spinlocks
making it useful for dispatching swi tasks from fast interrupt handlers.

Sponsered by:	FreeBSD Foundation
2003-09-05 23:09:22 +00:00
Kenneth D. Merry
cb32189e23 Move dynamic sysctl(8) variable creation for the cd(4) and da(4) drivers
out of cdregister() and daregister(), which are run from interrupt context.

The sysctl code does blocking mallocs (M_WAITOK), which causes problems
if malloc(9) actually needs to sleep.

The eventual fix for this issue will involve moving the CAM probe process
inside a kernel thread.  For now, though, I have fixed the issue by moving
dynamic sysctl variable creation for these two drivers to a task queue
running in a kernel thread.

The existing task queues (taskqueue_swi and taskqueue_swi_giant) run in
software interrupt handlers, which wouldn't fix the problem at hand.  So I
have created a new task queue, taskqueue_thread, that runs inside a kernel
thread.  (It also runs outside of Giant -- clients must explicitly acquire
and release Giant in their taskqueue functions.)

scsi_cd.c:	Remove sysctl variable creation code from cdregister(), and
		move it to a new function, cdsysctlinit().  Queue
		cdsysctlinit() to the taskqueue_thread taskqueue once we
		have fully registered the cd(4) driver instance.

scsi_da.c:	Remove sysctl variable creation code from daregister(), and
		move it to move it to a new function, dasysctlinit().
		Queue dasysctlinit() to the taskqueue_thread taskqueue once
		we have fully registered the da(4) instance.

taskqueue.h:	Declare the new taskqueue_thread taskqueue, update some
		comments.

subr_taskqueue.c:
		Create the new kernel thread taskqueue.  This taskqueue
		runs outside of Giant, so any functions queued to it would
		need to explicitly acquire/release Giant if they need it.

cd.4:		Update the cd(4) man page to talk about the minimum command
		size sysctl/loader tunable.  Also note that the changer
		variables are available as loader tunables as well.

da.4:		Update the da(4) man page to cover the retry_count,
		default_timeout and minimum_cmd_size sysctl variables/loader
		tunables.  Remove references to /dev/r???, they aren't used
		any longer.

cd.9:		Update the cd(9) man page to describe the CD_Q_10_BYTE_ONLY
		quirk.

taskqueue.9:	Update the taskqueue(9) man page to describe the new thread
		task queue, and the taskqueue_swi_giant queue.

MFC after:	3 days
2003-09-03 04:46:28 +00:00
David E. O'Brien
677b542ea2 Use __FBSDID(). 2003-06-11 00:56:59 +00:00
Scott Long
7874f606d5 Introduce a new taskqueue that runs completely free of Giant, and in
turns runs its tasks free of Giant too.  It is intended that as drivers
become locked down, they will move out of the old, Giant-bound taskqueue
and into this new one.  The old taskqueue has been renamed to
taskqueue_swi_giant, and the new one keeps the name taskqueue_swi.
2003-02-26 03:15:42 +00:00
John Baldwin
fbd140c786 If we fail to write to a vnode during a ktrace write, then we drop all
other references to that vnode as a trace vnode in other processes as well
as in any pending requests on the todo list.  Thus, it is possible for a
ktrace request structure to have a NULL ktr_vp when it is destroyed in
ktr_freerequest().  We shouldn't call vrele() on the vnode in that case.

Reported by:	bde
2002-08-01 13:35:38 +00:00
John Baldwin
6008862bc2 Change callers of mtx_init() to pass in an appropriate lock type name. In
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.

Tested on:	i386, alpha, sparc64
2002-04-04 21:03:38 +00:00
John Baldwin
c86b6ff551 Change the preemption code for software interrupt thread schedules and
mutex releases to not require flags for the cases when preemption is
not allowed:

The purpose of the MTX_NOSWITCH and SWI_NOSWITCH flags is to prevent
switching to a higher priority thread on mutex releease and swi schedule,
respectively when that switch is not safe.  Now that the critical section
API maintains a per-thread nesting count, the kernel can easily check
whether or not it should switch without relying on flags from the
programmer.  This fixes a few bugs in that all current callers of
swi_sched() used SWI_NOSWITCH, when in fact, only the ones called from
fast interrupt handlers and the swi_sched of softclock needed this flag.
Note that to ensure that swi_sched()'s in clock and fast interrupt
handlers do not switch, these handlers have to be explicitly wrapped
in critical_enter/exit pairs.  Presently, just wrapping the handlers is
sufficient, but in the future with the fully preemptive kernel, the
interrupt must be EOI'd before critical_exit() is called.  (critical_exit()
can switch due to a deferred preemption in a fully preemptive kernel.)

I've tested the changes to the interrupt code on i386 and alpha.  I have
not tested ia64, but the interrupt code is almost identical to the alpha
code, so I expect it will work fine.  PowerPC and ARM do not yet have
interrupt code in the tree so they shouldn't be broken.  Sparc64 is
broken, but that's been ok'd by jake and tmm who will be fixing the
interrupt code for sparc64 shortly.

Reviewed by:	peter
Tested on:	i386, alpha
2002-01-05 08:47:13 +00:00
John Baldwin
282873e2c0 - Change the taskqueue locking to protect the necessary parts of a task
while it is on a queue with the queue lock and remove the per-task locks.
- Remove TASK_DESTROY now that it is no longer needed.
- Go back to inlining TASK_INIT now that it is short again.

Inspired by:	dfr
2001-10-26 18:46:48 +00:00
John Baldwin
1de1c550b1 Add locking to taskqueues. There is one mutex per task, one mutex per
queue, and a mutex to protect the global list of taskqueues.  The only
visible change is that a TASK_DESTROY() macro has been added to mirror
the TASK_INIT() macro to destroy a task before it is free'd.

Submitted by:	Andrew Reiter <awr@watson.org>
2001-10-26 06:32:21 +00:00
Alfred Perlstein
a428c5ffef remove include of ipl.h because it no longer exists 2001-05-16 02:52:06 +00:00
John Baldwin
062d8ff5a0 - Catch up to the new swi API changes:
- Use swi_* function names.
  - Use void * to hold cookies to handlers instead of struct intrhand *.
- In sio.c, use 'driver_name' instead of "sio" as the name of the driver
  lock to minimize diffs with cy(4).
2001-02-09 17:46:35 +00:00
Poul-Henning Kamp
959b7375ed Staticize some malloc M_ instances. 2000-12-08 20:09:00 +00:00
John Baldwin
8088699f79 - Overhaul the software interrupt code to use interrupt threads for each
type of software interrupt.  Roughly, what used to be a bit in spending
  now maps to a swi thread.  Each thread can have multiple handlers, just
  like a hardware interrupt thread.
- Instead of using a bitmask of pending interrupts, we schedule the specific
  software interrupt thread to run, so spending, NSWI, and the shandlers
  array are no longer needed.  We can now have an arbitrary number of
  software interrupt threads.  When you register a software interrupt
  thread via sinthand_add(), you get back a struct intrhand that you pass
  to sched_swi() when you wish to schedule your swi thread to run.
- Convert the name of 'struct intrec' to 'struct intrhand' as it is a bit
  more intuitive.  Also, prefix all the members of struct intrhand with
  'ih_'.
- Make swi_net() a MI function since there is now no point in it being
  MD.

Submitted by:	cp
2000-10-25 05:19:40 +00:00
John Baldwin
1931cf940a - Heavyweight interrupt threads on the alpha for device I/O interrupts.
- Make softinterrupts (SWI's) almost completely MI, and divorce them
  completely from the x86 hardware interrupt code.
  - The ihandlers array is now gone.  Instead, there is a MI shandlers array
    that just contains SWI handlers.
  - Most of the former machine/ipl.h files have moved to a new sys/ipl.h.
- Stub out all the spl*() functions on all architectures.

Submitted by:	dfr
2000-10-05 23:09:57 +00:00
John Baldwin
9a94c9c5c3 - Remove the inthand2_t type and use the equivalent driver_intr_t type from
newbus for referencing device interrupt handlers.
- Move the 'struct intrec' type which describes interrupt sources into
  sys/interrupt.h instead of making it just be a x86 structure.
- Don't create 'ithd' and 'intrec' typedefs, instead, just use 'struct ithd'
  and 'struct intrec'
- Move the code to translate new-bus interrupt flags into an interrupt thread
  priority out of the x86 nexus code and into a MI ithread_priority()
  function in sys/kern/kern_intr.c.
- Remove now-uneeded x86-specific headers from sys/dev/ata/ata-all.c and
  sys/pci/pci_compat.c.
2000-09-13 18:33:25 +00:00
Jeffrey Hsu
51b86781c0 Modify to use fixed STAILQ_LAST().
Reviewed by:	dfr
2000-08-03 16:37:46 +00:00
Doug Rabson
ca2e05343b Add taskqueue system for easy-to-use SWIs among other things.
Reviewed by: arch
2000-05-28 15:45:30 +00:00