Commit Graph

176 Commits

Author SHA1 Message Date
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
Jake Burkholder
d5a08a6065 Implement a unified run queue and adjust priority levels accordingly.
- All processes go into the same array of queues, with different
  scheduling classes using different portions of the array.  This
  allows user processes to have their priorities propogated up into
  interrupt thread range if need be.
- I chose 64 run queues as an arbitrary number that is greater than
  32.  We used to have 4 separate arrays of 32 queues each, so this
  may not be optimal.  The new run queue code was written with this
  in mind; changing the number of run queues only requires changing
  constants in runq.h and adjusting the priority levels.
- The new run queue code takes the run queue as a parameter.  This
  is intended to be used to create per-cpu run queues.  Implement
  wrappers for compatibility with the old interface which pass in
  the global run queue structure.
- Group the priority level, user priority, native priority (before
  propogation) and the scheduling class into a struct priority.
- Change any hard coded priority levels that I found to use
  symbolic constants (TTIPRI and TTOPRI).
- Remove the curpriority global variable and use that of curproc.
  This was used to detect when a process' priority had lowered and
  it should yield.  We now effectively yield on every interrupt.
- Activate propogate_priority().  It should now have the desired
  effect without needing to also propogate the scheduling class.
- Temporarily comment out the call to vm_page_zero_idle() in the
  idle loop.  It interfered with propogate_priority() because
  the idle process needed to do a non-blocking acquire of Giant
  and then other processes would try to propogate their priority
  onto it.  The idle process should not do anything except idle.
  vm_page_zero_idle() will return in the form of an idle priority
  kernel thread which is woken up at apprioriate times by the vm
  system.
- Update struct kinfo_proc to the new priority interface.  Deliberately
  change its size by adjusting the spare fields.  It remained the same
  size, but the layout has changed, so userland processes that use it
  would parse the data incorrectly.  The size constraint should really
  be changed to an arbitrary version number.  Also add a debug.sizeof
  sysctl node for struct kinfo_proc.
2001-02-12 00:20:08 +00:00
Jake Burkholder
3cbe75a414 Clear the reschedule flag after finding it set in userret(). This
used to be in cpu_switch(), but I don't see any difference between
doing it here.
2001-02-10 20:33:35 +00:00
John Baldwin
142ba5f3d7 - Make astpending and need_resched process attributes rather than CPU
attributes.  This is needed for AST's to be properly posted in a preemptive
  kernel.  They are backed by two new flags in p_sflag: PS_ASTPENDING and
  PS_NEEDRESCHED.  They are still accesssed by their old macros:
  aston(), astoff(), etc.  For completeness, an astpending() macro has been
  added to check for a pending AST, and clear_resched() has been added to
  clear need_resched().
- Rename syscall2() on the x86 back to syscall() to be consistent with
  other architectures.
2001-02-10 02:20:34 +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
297c46b68c Don't enable interrupts for a kernel breakpoint or trace trap. Otherwise,
this negates the explicit disabling of interrupts when entering the
debugger in Debugger().
2001-02-08 00:10:07 +00:00
Jeroen Ruigrok van der Werven
1a6e52d0e9 Fix typo: seperate -> separate.
Seperate does not exist in the english language.
2001-02-06 11:21:58 +00:00
Peter Wemm
03927d3c33 Send "#if NISA > 0" to the bit-bucket and replace it with an option.
These were compile-time "is the isa code present?" tests and not
'how many isa busses' tests.
2001-01-29 09:38:39 +00:00
Jake Burkholder
28df158b49 Push Giant down into the trap handlers that need it, instead of
acquiring it unconditionally.

Reviewed by:	jhb
2001-01-26 04:16:16 +00:00
John Baldwin
625c76db3a - Kill the have_giant parameter to userret() along with all instances of
that name as a variable.  Use mtx_owned(&Giant) where appropriate
  instead.
- Proc locking.
- P_FOO -> PS_FOO.
- Update comments about enable interrupts during trap and why this may be
  bad if we trap while holding a spin mutex.
- Don't bother resetting p to curproc in syscall() in case we are the child
  returning from fork.  The child hasn't returned from fork through syscall
  in a while.
- Remove fork_return() as it has been superseded by the MI version.
2001-01-24 09:53:49 +00:00
Jake Burkholder
a448b62ac9 Make intr_nesting_level per-process, rather than per-cpu. Setup
interrupt threads to run with it always >= 1, so that malloc can
detect M_WAITOK from "interrupt" context.  This is also necessary
in order to context switch from sched_ithd() directly.

Reviewed By:	peter
2001-01-21 19:25:07 +00:00
Peter Wemm
558226eae7 Use #ifdef DEV_NPX from opt_npx.h instead of #if NNPX > 0 from npx.h 2001-01-19 13:19:02 +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
John Baldwin
05f9877c15 If we fail to emulate a vm86 trap in kernel mode, then we use
vm86_trap() to return to the calling program directly.  vm86_trap()
doesn't return, thus it was never returning to trap() to release
Giant.  Thus, release Giant before calling vm86_trap().
2000-12-13 18:57:15 +00:00
Jake Burkholder
92cf772d8d - Add code to detect if a system call returns with locks other than Giant
held and panic if so (conditional on witness).
- Change witness_list to return the number of locks held so this is easier.
- Add kern/syscalls.c to the kernel build if witness is defined so that the
  panic message can contain the name of the offending system call.
- Add assertions that Giant and sched_lock are not held when returning from
  a system call, which were missing for alpha and ia64.
2000-12-12 01:14:32 +00:00
Jake Burkholder
7da6f97772 - Split the run queue and sleep queue linkage, so that a process
may block on a mutex while on the sleep queue without corrupting
it.
- Move dropping of Giant to after the acquire of sched_lock.

Tested by:	John Hay <jhay@icomtek.csir.co.za>
		jhb
2000-11-17 18:09:18 +00:00
John Baldwin
20cdcc5b73 Don't release and acquire Giant in mi_switch(). Instead, release and
acquire Giant as needed in functions that call mi_switch().  The releases
need to be done outside of the sched_lock to avoid potential deadlocks
from trying to acquire Giant while interrupts are disabled.

Submitted by:	witness
2000-11-16 02:16:44 +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
a91b7dc11b Various whitespace cleanups after the SMPng commit, which jumbled things
around a bit in the trap handling code.
2000-10-06 01:55:07 +00:00
John Baldwin
0e2aab1237 Don't treat a kernel stack fault the same as a general protect fault or
a segment not present fault in the non-vm86 case.
2000-10-06 01:50:43 +00:00
Bruce Evans
9c15b3c143 Fixed hang on booting with -d. mtx_enter() was called on an uninitialized
lock.  The quick fix in trap.c was not quite the version tested and had no
effect; back it out.
2000-09-13 12:40:43 +00:00
Bruce Evans
bbbb2579b4 Quick fix for hang on booting with -d. mtx_enter() was called before
curproc was initialized.  curproc == NULL was interpreted as matching
the process holding Giant...  Just skip mtx_enter() and mtx_exit() in
trap() if (curproc == NULL && cold) (&& cold for safety).
2000-09-12 18:41:56 +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
Paul Saab
c206a8609e Change the behavior of isa_nmi to log an error message instead of
panicing and return a status so that we can decide whether to drop
into DDB or panic.  If the status from isa_nmi is true, panic the
kernel based on machdep.panic_on_nmi, otherwise if DDB is
enabled, drop to DDB based on machdep.ddb_on_nmi.

Reviewed by:	peter, phk
2000-08-06 14:17:21 +00:00
Luoqi Chen
3fb50adb4c Handle write page faults (both write only or read-modify-write) as MI vm
write-only faults.  This would allow write-only mmapped regions to function
correctly.
2000-07-31 14:47:14 +00:00
Paul Saab
88f675ba30 Change the way NMI's are handled. Before, if DDB was enabled and
a NMI occured, you could type continue in DDB and the kernel would
not attempt to detect what type of NMI was recieved.  Now we check
for the type of NMI first and then go to DDB if it is enabled.

This will solve the problem with having DDB enabled and getting an
NMI due to some possibly bad error and being able to continue the
operation of the kernel when you really want to panic and know
what happened.

Submitted by:	jhb
2000-07-14 11:49:44 +00:00
Brian S. Dean
c6d3f3bfc1 Fix my own style bugs (use of spaces instead of tabs for indentation).
This is a style-only change.
2000-07-01 02:40:13 +00:00
Matthew Dillon
36e9f877df Commit major SMP cleanups and move the BGL (big giant lock) in the
syscall path inward.  A system call may select whether it needs the MP
    lock or not (the default being that it does need it).

    A great deal of conditional SMP code for various deadended experiments
    has been removed.  'cil' and 'cml' have been removed entirely, and the
    locking around the cpl has been removed.  The conditional
    separately-locked fast-interrupt code has been removed, meaning that
    interrupts must hold the CPL now (but they pretty much had to anyway).
    Another reason for doing this is that the original separate-lock for
    interrupts just doesn't apply to the interrupt thread mechanism being
    contemplated.

    Modifications to the cpl may now ONLY occur while holding the MP
    lock.  For example, if an otherwise MP safe syscall needs to mess with
    the cpl, it must hold the MP lock for the duration and must (as usual)
    save/restore the cpl in a nested fashion.

    This is precursor work for the real meat coming later: avoiding having
    to hold the MP lock for common syscalls and I/O's and interrupt threads.
    It is expected that the spl mechanisms and new interrupt threading
    mechanisms will be able to run in tandem, allowing a slow piecemeal
    transition to occur.

    This patch should result in a moderate performance improvement due to
    the considerable amount of code that has been removed from the critical
    path, especially the simplification of the spl*() calls.  The real
    performance gains will come later.

Approved by: jkh
Reviewed by: current, bde (exception.s)
Some work taken from: luoqi's patch
2000-03-28 07:16:37 +00:00
Peter Dufault
6d9a8d3e8f I applied the wrong patch set. Back out anything associated
with the known bogus currtpriority.  This undoes the previous changes to
sys/i386/i386/trap.c, sys/alpha/alpha/trap.c, sys/sys/systm.h

Now we have the patch set approved by bde.

Approved by:	bde
2000-03-02 22:03:49 +00:00
Peter Dufault
383774c417 Patches that eliminate extra context switches in FIFO case.
Fixes p1003_1b regression test in the simple case of no RR and
FIFO processes competing.

Reviewed by:	jkh, bde
2000-03-02 16:20:07 +00:00
Brian S. Dean
de8050f9b8 Don't forget to reset the hardware debug registers when a process that
was using them exits.

Don't allow a user process to cause the kernel to take a TRCTRAP on a
user space address.

Reviewed by:	jlemon, sef
Approved by:	jkh
2000-02-20 20:51:23 +00:00
Kazutaka YOKOTA
35e61cbd71 Add a new mechanism, cndbctl(), to tell the console driver that
ddb is entered.  Don't refer to `in_Debugger' to see if we
are in the debugger.  (The variable used to be static in Debugger()
and wasn't updated if ddb is entered via traps and panic anyway.)

- Don't refer to `in_Debugger'.
- Add `db_active' to i386/i386/db_interface.d (as in
  alpha/alpha/db_interface.c).
- Remove cnpollc() stub from ddb/db_input.c.
- Add the dbctl function to syscons, pcvt, and sio. (The function for
  pcvt and sio is noop at the moment.)

Jointly developed by: bde and me

(The final version was tweaked by me and not reviewed by bde.  Thus,
if there is any error in this commit, that is entirely of mine, not
his.)

Some changes were obtained from: NetBSD
2000-01-11 14:54:01 +00:00
Alan Cox
b561683329 Passing "0" or "FALSE" as the fourth argument to vm_fault is wrong. It
should be "VM_FAULT_NORMAL".
1999-11-09 01:44:28 +00:00
Poul-Henning Kamp
923502ff91 useracc() the prequel:
Merge the contents (less some trivial bordering the silly comments)
of <vm/vm_prot.h> and <vm/vm_inherit.h> into <vm/vm.h>.  This puts
the #defines for the vm_inherit_t and vm_prot_t types next to their
typedefs.

This paves the road for the commit to follow shortly: change
useracc() to use VM_PROT_{READ|WRITE} rather than B_{READ|WRITE}
as argument.
1999-10-29 18:09:36 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Martin Cracauer
a7674320e9 On FPU exceptions, pass a useful error code (one of the FPE_...
macros) to the signal handler, for old-style BSD signal handlers as
the second (int) argument, for SA_SIGINFO signal handlers as
siginfo_t->si_code. This is source-compatible with Solaris, except
that we have no <siginfo.h> (which isn't even mentioned in POSIX
1003.1b).

An rather complete example program is at
  http://www3.cons.org/cracauer/freebsd-signal.c
This will be added to the regression tests in src/.

This commit also adds code to disable the (hardware) FPU from
userconfig, so that you can use a software FP emulator on a machine
that has hardware floating point. See LINT.
1999-07-25 13:16:09 +00:00
Bruce Evans
50045fbc7c Changed the global `idt' from an array to a pointer so that npx.c
automatically hacks on the active copy of the IDT if f00f_hack()
has changed it.  This also allows simplifications in setidt().
This fixes breakage of FP exception handling by rev.1.55 of
sys/kernel.h.  FP exceptions were sent to npx.c's probe handlers
because npx.c "restored" the old handlers to the wrong copy of the
IDT.  The SYSINIT for f00f_hack() was purposely run quite late to
avoid problems like this, but it is bogusly associated with the
SYSINIT for proc0 so it was moved with the latter.

Problem reported and fix tested by:  Martin Cracauer <cracauer@cons.org>
1999-06-18 14:32:21 +00:00
Jonathan Lemon
eb9d435ae7 Unifdef VM86.
Reviewed by:	silence on on -current
1999-06-01 18:20:36 +00:00
Peter Wemm
dfd5dee1b0 Add sufficient braces to keep egcs happy about potentially ambiguous
if/else nesting.
1999-05-06 18:13:11 +00:00
Luoqi Chen
5206bca10a Enable vmspace sharing on SMP. Major changes are,
- %fs register is added to trapframe and saved/restored upon kernel entry/exit.
- Per-cpu pages are no longer mapped at the same virtual address.
- Each cpu now has a separate gdt selector table. A new segment selector
  is added to point to per-cpu pages, per-cpu global variables are now
  accessed through this new selector (%fs). The selectors in gdt table are
  rearranged for cache line optimization.
- fask_vfork is now on as default for both UP and SMP.
- Some aio code cleanup.

Reviewed by:	Alan Cox	<alc@cs.rice.edu>
		John Dyson	<dyson@iquest.net>
		Julian Elischer	<julian@whistel.com>
		Bruce Evans	<bde@zeta.org.au>
		David Greenman	<dg@root.com>
1999-04-28 01:04:33 +00:00
Peter Wemm
db42d90829 unifdef -DVM_STACK - it's been on for a while for x86 and was checked
and appeared to be working for the Alpha some time ago.
1999-04-19 14:14:14 +00:00
Poul-Henning Kamp
a2210fe12b Make TIMER_FREQ a normal, undocumented option. Raise confusion to
a higher level with example in LINT.

Clarify comment about PPS_SYNC.  Ignore for now that it doesn't
work in FLL mode, it will in a few days.
1999-03-09 20:20:09 +00:00
Julian Elischer
2267af789e Add (but don't activate) code for a special VM option to make
downward growing stacks more general.
Add (but don't activate) code to use the new stack facility
when running threads, (specifically the linux threads support).
This allows people to use both linux compiled linuxthreads, and also the
native FreeBSD linux-threads port.

The code is conditional on VM_STACK. Not using this will
produce the old heavily tested system.

Submitted by: Richard Seaman <dick@tar.com>
1999-01-06 23:05:42 +00:00
Mike Smith
9959b1a882 Improved DDB_UNATTENDED behaviour. From the submitter:
There's something that's been bugging me for a while, so I decided to fix it.
FreeBSD now will DTRT WRT DDB and DDB_UNATTENDED (!debugger_on_panic), at least
in my opinion. The behavior change is such that:

	1. Nothing changes when debugger_on_panic != 0.
	2. When DDB_UNATTENDED (!debugger_on_panic), if a panic occurs, the
		machine will reboot. Also, if a trap occurs, the machine will
		panic and reboot, unlike how it broke to DDB before. HOWEVER,
		a trap inside DDB will not cause a panic, allowing full use
		of DDB without having to worry about the machine being stuck
		at a DDB prompt if something goes wrong during the day.
		Patches for this behavior follow my signature, and it would
		be a boon to anyone (like me) who uses DDB_UNATTENDED, but
		actually wants the machine to panic on a trap (otherwise,
		what's the use, if the machine causes a fatal trap rather than
		a true panic, of debugger_on_panic?). The changes cause no
		adverse behavior, but do involve two symbols becoming global

Submitted by:	Brian Feldman <green@unixhelp.org>
1998-12-28 23:03:00 +00:00
Bruce Evans
4f2129fa86 Removed bogus casts of USRSTACK and/or the other operand in binary
expressions involving USRSTACK.
1998-12-16 15:21:51 +00:00
Archie Cobbs
2326715f79 Avoid compiler warning (printf arg type mismatch) when compiling #ifdef DEBUG 1998-12-06 00:03:30 +00:00
KATO Takenori
9ad861edee - For some old Cyrix CPUs, %cr2 is clobbered by interrupts. This
problem is worked around by using an interrupt gate for the page
   fault handler.  This code was originally made for NetBSD/pc98 by
   Naofumi Honda <honda@kururu.math.sci.hokudai.ac.jp> and has already
   been in PC98 tree.  Because of this bug, trap_fatal cannot show
   correct page fault address if %cr2 is obtained in this function.
   Therefore, trap_fatal uses the value from trap() function.
-  The trap handler always enables interruption when buggy application
   or kernel code has disabled interrupts and then trapped.  This code
   was prepared by Bruce Evans <bde@FreeBSD.org>.

Submitted by:	Bruce Evans <bde@FreeBSD.org>
		Naofumi Honda <honda@kururu.math.sci.hokudai.ac.jp>
1998-12-02 08:15:17 +00:00
Bruce Evans
1fcee46997 Fixed printf format errors. 1998-08-23 10:16:26 +00:00
Eivind Eklund
288078be0f Translate T_PROTFLT to SIGSEGV instead of SIGBUS when running under
Linux emulation.  This make Allegro Common Lisp 4.3 work under
FreeBSD!

Submitted by: Fred Gilham <gilham@csl.sri.com>
Commented on by: bde, dg, msmith, tg
Hoping he got everything right:  eivind
1998-04-28 18:15:08 +00:00