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132 Commits

Author SHA1 Message Date
Luigi Rizzo
e4fc250c15 Device Polling code for -current.
Non-SMP, i386-only, no polling in the idle loop at the moment.

To use this code you must compile a kernel with

        options DEVICE_POLLING

and at runtime enable polling with

        sysctl kern.polling.enable=1

The percentage of CPU reserved to userland can be set with

        sysctl kern.polling.user_frac=NN (default is 50)

while the remainder is used by polling device drivers and netisr's.
These are the only two variables that you should need to touch. There
are a few more parameters in kern.polling but the default values
are adequate for all purposes. See the code in kern_poll.c for
more details on them.

Polling in the idle loop will be implemented shortly by introducing
a kernel thread which does the job. Until then, the amount of CPU
dedicated to polling will never exceed (100-user_frac).
The equivalent (actually, better) code for -stable is at

	http://info.iet.unipi.it/~luigi/polling/

and also supports polling in the idle loop.

NOTE to Alpha developers:
There is really nothing in this code that is i386-specific.
If you move the 2 lines supporting the new option from
sys/conf/{files,options}.i386 to sys/conf/{files,options} I am
pretty sure that this should work on the Alpha as well, just that
I do not have a suitable test box to try it. If someone feels like
trying it, I would appreciate it.

NOTE to other developers:
sure some things could be done better, and as always I am open to
constructive criticism, which a few of you have already given and
I greatly appreciated.
However, before proposing radical architectural changes, please
take some time to possibly try out this code, or at the very least
read the comments in kern_poll.c, especially re. the reason why I
am using a soft netisr and cannot (I believe) replace it with a
simple timeout.

Quick description of files touched by this commit:

sys/conf/files.i386
        new file kern/kern_poll.c
sys/conf/options.i386
        new option
sys/i386/i386/trap.c
        poll in trap (disabled by default)
sys/kern/kern_clock.c
        initialization and hardclock hooks.
sys/kern/kern_intr.c
        minor swi_net changes
sys/kern/kern_poll.c
        the bulk of the code.
sys/net/if.h
        new flag
sys/net/if_var.h
        declaration for functions used in device drivers.
sys/net/netisr.h
        NETISR_POLL
sys/dev/fxp/if_fxp.c
sys/dev/fxp/if_fxpvar.h
sys/pci/if_dc.c
sys/pci/if_dcreg.h
sys/pci/if_sis.c
sys/pci/if_sisreg.h
        device driver modifications
2001-12-14 17:56:12 +00:00
John Baldwin
21a7a9aeb6 Use MTX_QUIET for the lock operations during clock interrupts so their logs
don't drown out more useful log messages.
2001-11-15 19:54:48 +00:00
John Baldwin
61d80e90a9 Add missing includes of sys/ktr.h. 2001-10-11 17:53:43 +00:00
Julian Elischer
b40ce4165d KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after:    ha ha ha ha
2001-09-12 08:38:13 +00:00
John Baldwin
688ebe120c - Close races with signals and other AST's being triggered while we are in
the process of exiting the kernel.  The ast() function now loops as long
  as the PS_ASTPENDING or PS_NEEDRESCHED flags are set.  It returns with
  preemption disabled so that any further AST's that arrive via an
  interrupt will be delayed until the low-level MD code returns to user
  mode.
- Use u_int's to store the tick counts for profiling purposes so that we
  do not need sched_lock just to read p_sticks.  This also closes a
  problem where the call to addupc_task() could screw up the arithmetic
  due to non-atomic reads of p_sticks.
- Axe need_proftick(), aston(), astoff(), astpending(), need_resched(),
  clear_resched(), and resched_wanted() in favor of direct bit operations
  on p_sflag.
- Fix up locking with sched_lock some.  In addupc_intr(), use sched_lock
  to ensure pr_addr and pr_ticks are updated atomically with setting
  PS_OWEUPC.  In ast() we clear pr_ticks atomically with clearing
  PS_OWEUPC.  We also do not grab the lock just to test a flag.
- Simplify the handling of Giant in ast() slightly.

Reviewed by:	bde (mostly)
2001-08-10 22:53:32 +00:00
John Baldwin
c9c1406f76 Add KTR_INTR tracepoints for when clock interrupts are triggered. 2001-08-03 20:54:41 +00:00
John Baldwin
8bd57f8fc2 Remove unneeded includes of sys/ipl.h and machine/ipl.h. 2001-05-15 23:22:29 +00:00
John Baldwin
6caa8a1501 Overhaul of the SMP code. Several portions of the SMP kernel support have
been made machine independent and various other adjustments have been made
to support Alpha SMP.

- It splits the per-process portions of hardclock() and statclock() off
  into hardclock_process() and statclock_process() respectively.  hardclock()
  and statclock() call the *_process() functions for the current process so
  that UP systems will run as before.  For SMP systems, it is simply necessary
  to ensure that all other processors execute the *_process() functions when the
  main clock functions are triggered on one CPU by an interrupt.  For the alpha
  4100, clock interrupts are delievered in a staggered broadcast fashion, so
  we simply call hardclock/statclock on the boot CPU and call the *_process()
  functions on the secondaries.  For x86, we call statclock and hardclock as
  usual and then call forward_hardclock/statclock in the MD code to send an IPI
  to cause the AP's to execute forwared_hardclock/statclock which then call the
  *_process() functions.
- forward_signal() and forward_roundrobin() have been reworked to be MI and to
  involve less hackery.  Now the cpu doing the forward sets any flags, etc. and
  sends a very simple IPI_AST to the other cpu(s).  AST IPIs now just basically
  return so that they can execute ast() and don't bother with setting the
  astpending or needresched flags themselves.  This also removes the loop in
  forward_signal() as sched_lock closes the race condition that the loop worked
  around.
- need_resched(), resched_wanted() and clear_resched() have been changed to take
  a process to act on rather than assuming curproc so that they can be used to
  implement forward_roundrobin() as described above.
- Various other SMP variables have been moved to a MI subr_smp.c and a new
  header sys/smp.h declares MI SMP variables and API's.   The IPI API's from
  machine/ipl.h have moved to machine/smp.h which is included by sys/smp.h.
- The globaldata_register() and globaldata_find() functions as well as the
  SLIST of globaldata structures has become MI and moved into subr_smp.c.
  Also, the globaldata list is only available if SMP support is compiled in.

Reviewed by:	jake, peter
Looked over by:	eivind
2001-04-27 19:28:25 +00:00
John Baldwin
e3ee8974e3 Fix an old bug related to BETTER_CLOCK. Call forward_*clock if SMP
and __i386__ are defined rather than if SMP and BETTER_CLOCK are defined.
The removal of BETTER_CLOCK would have broken this except that kern_clock.c
doesn't include <machine/smptests.h>, so it doesn't see the definition of
BETTER_CLOCK, and forward_*clock aren't called, even on 4.x.  This seems to
fix the problem where a n-way SMP system would see 100 * n clk interrupts
and 128 * n rtc interrupts.
2001-04-17 17:53:36 +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
Bruce Evans
866546105a Changed the aston() family to operate on a specified process instead of
always on curproc.  This is needed to implement signal delivery properly
(see a future log message for kern_sig.c).

Debogotified the definition of aston().  aston() was defined in terms
of signotify() (perhaps because only the latter already operated on
a specified process), but aston() is the primitive.

Similar changes are needed in the ia64 versions of cpu.h and trap.c.
I didn't make them because the ia64 is missing the prerequisite changes
to make astpending and need_resched per-process and those changes are
too large to make without testing.
2001-02-19 04:15:59 +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
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
John Baldwin
01cd094c32 - Proc locking.
- P_FOO -> PS_FOO.
2001-01-24 10:43:25 +00:00
Jake Burkholder
ef73ae4b0c Use PCPU_GET, PCPU_PTR and PCPU_SET to access all per-cpu variables
other then curproc.
2001-01-10 04:43:51 +00:00
Robert Watson
7f112b0489 o Export cp_time ("CPU time statistics") using SYSCTL_OPAQUE.
This removes a reason that systat requires setgid kmem.  More to
  come.
2000-11-20 00:44:58 +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
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
35e0e5b311 Catch up to moving headers:
- machine/ipl.h -> sys/ipl.h
- machine/mutex.h -> sys/mutex.h
2000-10-20 07:58:15 +00:00
John Baldwin
6c56727456 - Change fast interrupts on x86 to push a full interrupt frame and to
return through doreti to handle ast's.  This is necessary for the
  clock interrupts to work properly.
- Change the clock interrupts on the x86 to be fast instead of threaded.
  This is needed because both hardclock() and statclock() need to run in
  the context of the current process, not in a separate thread context.
- Kill the prevproc hack as it is no longer needed.
- We really need Giant when we call psignal(), but we don't want to block
  during the clock interrupt.  Instead, use two p_flag's in the proc struct
  to mark the current process as having a pending SIGVTALRM or a SIGPROF
  and let them be delivered during ast() when hardclock() has finished
  running.
- Remove CLKF_BASEPRI, which was #ifdef'd out on the x86 anyways.  It was
  broken on the x86 if it was turned on since cpl is gone.  It's only use
  was to bogusly run softclock() directly during hardclock() rather than
  scheduling an SWI.
- Remove the COM_LOCK simplelock and replace it with a clock_lock spin
  mutex.  Since the spin mutex already handles disabling/restoring
  interrupts appropriately, this also lets us axe all the *_intr() fu.
- Back out the hacks in the APIC_IO x86 cpu_initclocks() code to use
  temporary fast interrupts for the APIC trial.
- Add two new process flags P_ALRMPEND and P_PROFPEND to mark the pending
  signals in hardclock() that are to be delivered in ast().

Submitted by:	jakeb (making statclock safe in a fast interrupt)
Submitted by:	cp (concept of delaying signals until ast())
2000-10-06 02:20:21 +00:00
John Baldwin
77044cb6d9 Clean up process accounting some more. Unfortunately, it is still not
quite right on i386 as the CPU who runs statclock() doesn't have a valid
clockframe to calculate statistics with.
2000-09-12 18:57:59 +00:00
Jason Evans
0384fff8c5 Major update to the way synchronization is done in the kernel. Highlights
include:

* Mutual exclusion is used instead of spl*().  See mutex(9).  (Note: The
  alpha port is still in transition and currently uses both.)

* Per-CPU idle processes.

* Interrupts are run in their own separate kernel threads and can be
  preempted (i386 only).

Partially contributed by:	BSDi (BSD/OS)
Submissions by (at least):	cp, dfr, dillon, grog, jake, jhb, sheldonh
2000-09-07 01:33:02 +00:00
Poul-Henning Kamp
77978ab8bc Previous commit changing SYSCTL_HANDLER_ARGS violated KNF.
Pointed out by:	bde
2000-07-04 11:25:35 +00:00
Poul-Henning Kamp
82d9ae4e32 Style police catches up with rev 1.26 of src/sys/sys/sysctl.h:
Sanitize SYSCTL_HANDLER_ARGS so that simplistic tools can grog our
sources:

        -sysctl_vm_zone SYSCTL_HANDLER_ARGS
        +sysctl_vm_zone (SYSCTL_HANDLER_ARGS)
2000-07-03 09:35:31 +00:00
Poul-Henning Kamp
3389ae9350 Remove ~25 unneeded #include <sys/conf.h>
Remove ~60 unneeded #include <sys/malloc.h>
2000-04-19 14:58:28 +00:00
Matthew Dillon
db6a426158 The SMP cleanup commit broke UP compiles. Make UP compiles work again. 2000-03-28 18:06:49 +00:00
Poul-Henning Kamp
91266b96c4 Isolate the Timecounter internals in their own two files.
Make the public interface more systematically named.

Remove the alternate method, it doesn't do any good, only ruins performance.

Add counters to profile the usage of the 8 access functions.

Apply the beer-ware to my code.

The weird +/- counts are caused by two repocopies behind the scenes:
	kern/kern_clock.c -> kern/kern_tc.c
	sys/time.h -> sys/timetc.h
(thanks peter!)
2000-03-20 14:09:06 +00:00
Poul-Henning Kamp
f1220da49c Fix sign reversal in adjtime(2).
Approved by:	jkh
2000-02-13 10:56:32 +00:00
Poul-Henning Kamp
2ac0d0a1f7 Make adjtime(2) adjust boottime so it doesn't cause non-monotonous
uptime.
1999-12-08 10:02:12 +00:00
Bruce Evans
71a62f8a05 Fixed some comments in statclock(). The previous commit made it clearer
that one comment was attached to null code.
1999-11-27 14:37:34 +00:00
Bruce Evans
8a9d4d98b1 Moved scheduling-related code to kern_synch.c so that it is easier to fix
and extend.  The new function containing the code is named schedclock()
as in NetBSD, but it has slightly different semantics (it already handles
incrementation of p->p_cpticks, and it should handle any calling frequency).

Agreed with in principle by:	dufault
1999-11-27 12:32:27 +00:00
Peter Wemm
de3f888991 #ifdef PPS_SYNC around "kapi" declaration to fix a -Wunused warning. 1999-10-10 16:18:36 +00:00
John Hay
b7424f2dfb Update the PPSAPI to draft-mogul-pps-api-05.txt which is the latest.
NOTE: This will break building ntpd until ntpd has been upgraded to also
support draft 05. People that want to build ntpd in the meantime can
get patches from me.
1999-10-09 14:49:56 +00:00
Bruce Evans
37d3877723 Moved the definition of `boottime' and its sysctl to the correct file. 1999-09-13 14:22:27 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Bruce Evans
a1a10fdfc0 Oops, the previous commit only worked in the one case it was tested for. 1999-07-24 20:21:10 +00:00
Bruce Evans
6b6ef746e5 Added a sysctl "kern.timecounter.hardware" for selecting the hardware
used for timecounting.  The possible values are the names of the
physically present harware timecounters ("i8254" and "TSC" on i386's).

Fixed some nearby bitrot in comments in <sys/time.h>.

Reviewed by:	phk
1999-07-18 15:07:20 +00:00
John Polstra
7ac9503b86 Remove four no-op casts. 1999-07-18 01:35:26 +00:00
Poul-Henning Kamp
0bb2226a4d Make the machdep.i8254_freq and machdep.tsc_freq sysctls modify the
timecounter as well

Asked for by:	bde, jhay
1999-04-25 09:00:00 +00:00
Poul-Henning Kamp
c4a6db710a Don't open window for race condition.
Detected by:	Reg Clemens <reg@dwf.com>
1999-04-02 13:57:21 +00:00
Poul-Henning Kamp
30f27235cb Fix an old cut&paste bogon.
Noticed by: bde
1999-03-12 21:58:54 +00:00
Poul-Henning Kamp
37d39f0a50 Remove duplicate include.
Noticed by: bde
1999-03-12 11:09:50 +00:00
Poul-Henning Kamp
32c203577a Make even more of the PPSAPI implementations generic.
FLL support in hardpps()

Various magic shuffles and improved comments

Style fixes from Bruce.
1999-03-11 15:09:51 +00:00
Poul-Henning Kamp
c68996e271 Integrate the new "nanokernel" PLL from Dave Mills.
This code is backwards compatible with the older "microkernel" PLL, but
allows ntpd v4 to use nanosecond resolution.  Many other improvements.

PPS_SYNC and hardpps() are NOT supported yet.
1999-03-08 12:36:14 +00:00
Luoqi Chen
1c6d46f93c Introduce machine-dependent macro pgtok() to convert page count to number
of kilobytes. Its definition for each architecture could be optimized to
avoid potential numerical overflows.
1999-02-19 19:34:49 +00:00
Luoqi Chen
b1028ad122 Hide access to vmspace:vm_pmap with inline function vmspace_pmap(). This
is the preparation step for moving pmap storage out of vmspace proper.

Reviewed by:	Alan Cox	<alc@cs.rice.edu>
		Matthew Dillion	<dillon@apollo.backplane.com>
1999-02-19 14:25:37 +00:00
Poul-Henning Kamp
510eb5b9db Make the previous behaviour the default, add a sysctl which you
can set if your hw/sw produces the "calcru negative..." message.

Setting the alternate method (sysctl -w kern.timecounter.method=1)
makes the the get{nano|micro}*() functions call the real thing at
resulting in a measurable but minor overhead.

I decided to NOT have the "calcru" change the method automatically
because you should be aware of this problem if you have it.

The problems currently seen, related to usleep and a few other corners
are fixed for both methods.
1998-11-29 20:31:02 +00:00
Poul-Henning Kamp
c2906d55d0 Make timecounters more resistant to badly behaved SW/HW which locks
out interrupts for too long.  If you still see the "calcru: negative
time..." message you can increase NTIMECOUNTER (see LINT).

Sideeffect is that a timecounter is required to not wrap around in
less than (1 + delta) seconds instead of the (1/hz + delta) required
until now.

Many thanks to: msmith, wpaul, wosch & bde
1998-11-23 09:59:02 +00:00
Søren Schmidt
8843cc3508 Add a kludge to prevent panicing when using VM86 and hitting here
with a NULL curproc.

Originally by: Tor Egge (IIRC)
1998-11-23 09:34:19 +00:00
Bruce Evans
fffd686a31 Fixed breakage of the GPROF case of statclock() in the previous commit. 1998-10-26 06:13:18 +00:00