Commit Graph

102 Commits

Author SHA1 Message Date
Gleb Smirnoff
68a57ebfad Improve ktr(4) logging for callout(9) subsystem. Log all inserts and
removals, including failures, into the callwheel.

XXX: Most of the CTR() macros are called with callout_lock spin mutex
held, thus won't be logged into file, if KTR_ALQ is used. Moving the
CTR() macros out from the spinlocked code would require copying of all
arguments. I'm too lazy to do this.
2006-10-11 14:57:03 +00:00
John Baldwin
b36f458861 Use the recently added msleep_spin() function to simplify the
callout_drain() logic.  We no longer need a separate non-spin mutex to
do sleep/wakeup with, instead we can now just use the one spin mutex to
manage all the callout functionality.
2006-02-23 19:13:12 +00:00
John Baldwin
21f9e816cd Oops, missed adding the required include.
Pointy hat to:	jhb
2005-09-15 20:20:36 +00:00
John Baldwin
53c0e1ff7d Replace the dont_sleep_in_callout mutex hack (similar to g_x{up,down})
with the disallow sleeping facility.
2005-09-15 20:09:08 +00:00
Gleb Smirnoff
d04304d155 Make callout_reset() return a non-zero value if a pending callout
was rescheduled. If there was no pending callout, then return 0.

Reviewed by:	iedowse, cperciva
2005-09-08 14:20:39 +00:00
Ian Dowse
57c037be1c When processing a timeout() callout and returning it to the free
list, set `curr_callout' to NULL. This ensures that we won't attempt
to cancel the current callout if the original callout structure
gets recycled while we wait to acquire Giant.

This is reported to fix an intermittent syscons problem that was
introduced by revision 1.96.
2005-02-11 00:14:00 +00:00
Ian Dowse
98c926b20f Add a mechanism for associating a mutex with a callout when the
callout is first initialised, using a new function callout_init_mtx().
The callout system will acquire this mutex before calling the callout
function and release it on return.

In addition, the callout system uses the mutex to avoid most of the
complications and race conditions inherent in asynchronous timer
facilities, so mutex-protected callouts have much simpler semantics.
As long as the mutex is held when invoking callout_stop() or
callout_reset(), then these functions will guarantee that the callout
will be stopped, even if softclock() had already begun to process
the callout.

Existing Giant-locked callouts will automatically pick up the new
race-free semantics. This should close a number of race conditions
in the USB code and probably other areas of the kernel too.

There should be no change in behaviour for "MP-safe" callouts; these
still need to use the techniques mentioned in timeout(9) to avoid
race conditions.
2005-02-07 02:47:33 +00:00
Colin Percival
7834081c88 Make "c->c_func = NULL" conditional on CALLOUT_LOCAL_ALLOC in both
places where it occurs, not just one. :-)

Pointed out by:	glebius
Pointy had to:	cperciva
2005-01-19 21:15:58 +00:00
Colin Percival
0ceba3d69c Make "c->c_func = NULL" conditional on the CALLOUT_LOCAL_ALLOC flag,
i.e., only clear c->c_func if the callout c is being used via the old
timeout(9) interface.

Requested by:	glebius
2005-01-19 20:34:46 +00:00
Colin Percival
86fd19de7b Clarify the description of the callout_active() macro: It is cleared by
callout_stop, callout_drain, and callout_deactivate, but is not
automatically cleared when a callout returns.
2005-01-19 19:46:35 +00:00
Colin Percival
e9dec2c41b Adjust two of my comments to the new world order: Indent protection in
the first column is performed using /**, not /*-.
2005-01-07 03:25:45 +00:00
Robert Watson
ff7ec58af8 Cut a KTR record whenever a callout is invoked. Mark whether it runs
with Giant or not, and include the function point so it can be looked
up against the kernel symbol table during trace analysis.
2004-08-06 21:49:00 +00:00
Colin Percival
0413bacd09 When reseting a pending callout, perform the deregistration in
callout_reset rather than calling callout_stop.  This results in a few
lines of code duplication, but it provides a significant performance
improvement because it avoids recursing on callout_lock.

Requested by:	rwatson
2004-08-06 02:44:58 +00:00
Hiten Pandya
024035e822 The paper "Hashed Timers and Hierarchical Wheels: Data Structures for the
Efficient Implementation of a Timer Facility" was co-author'ed by T. Lauk,
not A. Lauk.

Adjust nearby whitespace.
2004-04-25 04:10:17 +00:00
Colin Percival
05641e82d7 1. Remove callout_stop binary compatibility.
2. Document that this means that kernel modules must be rebuilt.
3. While I'm here, fix my sorting error in callout.h

Requested by:	many [1], scottl [2], bde [3]
2004-04-20 15:49:31 +00:00
Colin Percival
49a74476a6 Add whitespace before comment blocks. (reported by njl)
Remove spurious whitespace, add indent protection, fix punctuation,
remove initialization of static variables to zero, put wakeup_ctr
and wakeup_needed in the correct order. (reported by bde)

This doesn't fix all the style bugs I introduced, but the remaining
style bugs make it easier for me to understand what I did here.
2004-04-08 02:03:49 +00:00
Colin Percival
2c1bb20746 Introduce a callout_drain() function. This acts in the same manner as
callout_stop(), except that if the callout being stopped is currently
in progress, it blocks attempts to reset the callout and waits until the
callout is completed before it returns.

This makes it possible to clean up callout-using code safely, e.g.,
without potentially freeing memory which is still being used by a callout.

Reviewed by:	mux, gallatin, rwatson, jhb
2004-04-06 23:08:49 +00:00
Warner Losh
7f8a436ff2 Remove advertising clause from University of California Regent's license,
per letter dated July 22, 1999.

Approved by: core
2004-04-05 21:03:37 +00:00
Poul-Henning Kamp
377e7be416 Make the DIAGNOSTIC code which complains about long {call|time}out(9)
functions less noisy:  We printf if a new function took longer than
the previous record holder, or of the previous record holder took
more than twice as long as the current record.
2003-12-07 20:03:28 +00:00
Poul-Henning Kamp
d87526cf43 Rename the debugging mutex "callout_no_sleep" to "dont_sleep_in_callout". 2003-11-15 18:33:54 +00:00
Kirk McKusick
48b0f4b67d At the request of several developers, restore the DIAGNOSIC code
deleted in 1.81. Increase the initial timeout limit to 2ms to
eliminate spurious messages of excessive timeouts in the NFS
client code.

Requested by:	Poul-Henning Kamp <phk@phk.freebsd.dk>
Requested by:	Mike Silbersack <silby@silby.com>
Requested by:	Sam Leffler <sam@errno.com>
2003-11-12 22:28:27 +00:00
Kirk McKusick
b932dd9b28 Get rid of DIAGNOSTIC that gives false positives on slow CPUs. 2003-11-04 08:03:11 +00:00
Marcel Moolenaar
38bf4e9667 On ia64 time_t is 64 bit. Explicitly cast tv_sec to long and change
the corresponding format specifier to %ld in a call to printf() in
function softclock(). The printf() is conditional upon DIAGNOSTIC.

Found by: LINT
2003-08-23 08:31:32 +00:00
Poul-Henning Kamp
166400b7e6 Don't put callout_lock under #ifdef DIAGNOSTIC despite the fact that it
works anyway.
2003-06-20 08:39:04 +00:00
Poul-Henning Kamp
ce6912c420 Crude but efficient:
#ifdef DIAGNOSTIC hold a mutex while calling callout's so that we hear
about it if they sleep.
2003-06-20 08:07:15 +00:00
David E. O'Brien
677b542ea2 Use __FBSDID(). 2003-06-11 00:56:59 +00:00
Poul-Henning Kamp
22ee8c4f50 Add instrumentation which tells us how much work softclock() does
per invocation.
2003-06-04 05:25:58 +00:00
Poul-Henning Kamp
33bef83cc6 Under DIAGNOSTIC, only report expensive timeouts if they are more expensive
than the last on we reported.
2003-02-01 10:06:40 +00:00
Poul-Henning Kamp
32c6c4780a Fix a format buglet.
Spotted by:	iedowse
2002-09-05 11:42:03 +00:00
Poul-Henning Kamp
b336df68d1 Under DIAGNOSTIC, complain if a timeout(9) routine took more than 1msec. 2002-09-04 20:05:00 +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
Alfred Perlstein
4d77a549fe Remove __P. 2002-03-19 21:25:46 +00:00
Matthew Dillon
219d632c15 Move most of the kernel submap initialization code, including the
timeout callwheel and buffer cache, out of the platform specific areas
and into the machine independant area.  i386 and alpha adjusted here.
Other cpus can be fixed piecemeal.

Reviewed by:    freebsd-smp, jake
2001-08-22 04:07:27 +00:00
John Baldwin
a45982d2ea Change callout_stop() to return an integer. If callout_stop() succeeds in
removing the callout entry, return 1.  If callout_stop() fails to remove
the callout entry because it is currently executing or has already been
executed, then the function returns 0.  The idea was obtained from BSD/OS,
however, BSD/OS changed untimeout(), and I've just changed callout_stop()
to be more conservative.

Obtained from:	BSD/OS
2001-08-10 21:06:59 +00:00
John Baldwin
ab32297d8d Axe spl's obsoleted by the callout mutex. 2001-08-10 01:36:25 +00:00
John Baldwin
f34fa851e0 Catch up to header include changes:
- <sys/mutex.h> now requires <sys/systm.h>
- <sys/mutex.h> and <sys/sx.h> now require <sys/lock.h>
2001-03-28 09:17:56 +00:00
Bosko Milekic
9ed346bab0 Change and clean the mutex lock interface.
mtx_enter(lock, type) becomes:

mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)

similarily, for releasing a lock, we now have:

mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.

The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.

Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:

MTX_QUIET and MTX_NOSWITCH

The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:

mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.

Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.

Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.

Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.

Finally, caught up to the interface changes in all sys code.

Contributors: jake, jhb, jasone (in no particular order)
2001-02-09 06:11:45 +00:00
Jonathan Lemon
e82ac18e52 Revert the last commit to the callout interface, and add a flag to
callout_init() indicating whether the callout is safe or not.  Update
the callers of callout_init() to reflect the new interface.

Okayed by: Jake
2000-11-25 06:22:16 +00:00
Jake Burkholder
249849e0b9 - Rename callout_reset to _callout_reset and add a flags argument.
- Add macros callout_reset, which does the obvious, and
  mp_callout_reset, which passes the CALLOUT_MPSAFE flag.
2000-11-25 03:34:49 +00:00
Jake Burkholder
fa2fbc3dac - Protect the callout wheel with a separate spin mutex, callout_lock.
- Use the mutex in hardclock to ensure no races between it and
  softclock.
- Make softclock be INTR_MPSAFE and provide a flag,
  CALLOUT_MPSAFE, which specifies that a callout handler does not
  need giant.  There is still no way to set this flag when
  regstering a callout.

Reviewed by:	-smp@, jlemon
2000-11-19 06:02:32 +00:00
John Baldwin
b6b55e27a4 Release sched_lock very briefly to give interrupts a chance to fire if we
are in softclock() for a long time.  The old code already did an
splx()/slphigh() pair here, I just missed adding in the equivalent mutex
operations on sched_lock earlier.
2000-11-18 00:21:00 +00:00
John Baldwin
cb799bfef9 The recent changes to msleep() and mawait() resulted in timeout() and
untimeout() not being called with Giant in those functions.  For now,
use the sched_lock to protect the callout wheel in softclock() and in
the various timeout and callout functions.

Noticed by:	tegge
2000-11-16 21:20:52 +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
Jonathan Lemon
9b8b58e033 Restructure TCP timeout handling:
- eliminate the fast/slow timeout lists for TCP and instead use a
    callout entry for each timer.
  - increase the TCP timer granularity to HZ
  - implement "bad retransmit" recovery, as presented in
    "On Estimating End-to-End Network Path Properties", by Allman and Paxson.

Submitted by:	jlemon, wollmann
1999-08-30 21:17:07 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Garrett Wollman
7347e1c6ab Fix callout_init(). This didn't have any practical effect since it
was only used to initialize the static timeouts, which unconditionally
clears the only bits which could have caused problems.
1999-03-06 22:27:02 +00:00
Garrett Wollman
acc8326d0c Expose a slightly-lower-level interface to timeouts which allows callers
to manage their own memory.  Tested on my machine (make buildworld).
I've made analogous changes on the alpha, but don't have a machine
to test.

Not-objected-to by:	dg, gibbs
1999-03-06 04:46:20 +00:00
Bruce Evans
c8b4782815 Fixed stale references to hzto() in comments. 1998-05-17 20:08:05 +00:00
Bruce Evans
8f03c6f18f Declare function pointer args as pointers, not as functions. 1998-02-25 06:13:32 +00:00
Poul-Henning Kamp
15b7a47005 A bunch of nits from bde. 1998-02-15 14:15:21 +00:00