Commit Graph

321 Commits

Author SHA1 Message Date
Jonathan Mini
aaa1c7715b Revert removal of cred_free_thread(): It is used to ensure that a thread's
credentials are not improperly borrowed when the thread is not current in
the kernel.

Requested by:	jhb, alfred
2002-07-11 02:18:33 +00:00
Julian Elischer
ad22735e3f Don't slow every syscall and trap by doing locks and stuff if the
'stop' bits are not set. This is a temporary thing.. I think this code probably
needs to be rewritten anyhow.
2002-07-10 06:40:22 +00:00
Julian Elischer
e602ba25fd Part 1 of KSE-III
The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)

Reviewed by:	Almost everyone who counts
	(at various times, peter, jhb, matt, alfred, mini, bernd,
	and a cast of thousands)

	NOTE: this is still Beta code, and contains lots of debugging stuff.
	expect slight instability in signals..
2002-06-29 17:26:22 +00:00
Jonathan Mini
01ad8a53db Remove unused diagnostic function cread_free_thread().
Approved by:	alfred
2002-06-24 06:22:00 +00:00
John Baldwin
d0c149fce8 We no longer need to acqure Giant in ast() for ktrpsig() in postsig() now
that ktrace no longer needs Giant.
2002-06-07 05:43:40 +00:00
Julian Elischer
628855e758 CURSIG() is not a macro so rename it cursig().
Obtained from:	KSE tree
2002-05-29 23:44:32 +00:00
Bruce Evans
79065dba2a Moved signal handling and rescheduling from userret() to ast() so that
they aren't in the usual path of execution for syscalls and traps.
The main complication for this is that we have to set flags to control
ast() everywhere that changes the signal mask.

Avoid locking in userret() in most of the remaining cases.

Submitted by:	luoqi (first part only, long ago, reorganized by me)
Reminded by:	dillon
2002-04-04 17:49:48 +00:00
Jake Burkholder
b454c6dd29 Style fixes purposefully left out of last commit. I checked the kse tree
and didn't see any changes that this conflicts with.
2002-03-29 16:45:03 +00:00
Jake Burkholder
d0ce9a7e07 Remove abuse of intr_disable/restore in MI code by moving the loop in ast()
back into the calling MD code.  The MD code must ensure no races between
checking the astpening flag and returning to usermode.

Submitted by:	peter (ia64 bits)
Tested on:	alpha (peter, jeff), i386, ia64 (peter), sparc64
2002-03-29 16:35:26 +00:00
Warner Losh
cb9a238a8a Remove last two abuses of cpu_critical_{enter,exit} in the MI code.
Reviewed by: jake, jhb, rwatson
2002-03-21 06:11:09 +00:00
John Baldwin
01c04d2de9 Change the way we ensure td_ucred is NULL if DIAGNOSTIC is defined.
Instead of caching the ucred reference, just go ahead and eat the
decerement and increment of the refcount.  Now that Giant is pushed down
into crfree(), we no longer have to get Giant in the common case.  In the
case when we are actually free'ing the ucred, we would normally free it on
the next kernel entry, so the cost there is not new, just in a different
place.  This also removse td_cache_ucred from struct thread.  This is
still only done #ifdef DIAGNOSTIC.

[ missed this file in the previous commit ]

Tested on:	i386, alpha
2002-03-20 21:12:04 +00:00
Jake Burkholder
39dda4e363 Make this compile.
Pointy hat to:	julian
2002-02-23 01:42:13 +00:00
Julian Elischer
77c4066424 Add some DIAGNOSTIC code.
While in userland, keep the thread's ucred reference in a shadow
field so that the usual place to store it is NULL.
If DIAGNOSTIC is not set, the thread ucred is kept valid until the next
kernel entry, at which time it is checked against the process cred
and possibly corrected. Produces a BIG speedup in
kernels with INVARIANTS set. (A previous commit corrected it
for the non INVARIANTS case already)

Reviewed by:	dillon@freebsd.org
2002-02-22 23:58:22 +00:00
Julian Elischer
2eb927e2bb If the credential on an incoming thread is correct, don't bother
reaquiring it. In the same vein, don't bother dropping the thread cred
when goinf ot userland. We are guaranteed to nned it when we come back,
(which we are guaranteed to do).

Reviewed by:	jhb@freebsd.org, bde@freebsd.org (slightly different version)
2002-02-17 01:09:56 +00:00
Julian Elischer
2c1007663f In a threaded world, differnt priorirites become properties of
different entities.  Make it so.

Reviewed by:	jhb@freebsd.org (john baldwin)
2002-02-11 20:37:54 +00:00
Bruce Evans
e744f30933 Changed the type of pcb_flags from u_char to u_int and adjusted things.
This removes the only atomic operation on a char type in the entire
kernel.
2002-01-17 17:49:23 +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
9d234f99f7 Axe a stale comment. Holding sched_lock across both setrunqueue() and
mi_switch() is sufficient.
2002-01-04 10:55:51 +00:00
John Baldwin
48fd1f38ee - Change all callers of addupc_task() to check PS_PROFIL explicitly and
remove the check from addupc_task().  It would need sched_lock while
  testing the flag anyways.
- Always read sticks while holding sched_lock using a temporary variable
  where needed.
- Always init prticks to 0 in ast() to quiet a warning.
2001-12-18 09:06:10 +00:00
John Baldwin
7e1f6dfe9d Modify the critical section API as follows:
- The MD functions critical_enter/exit are renamed to start with a cpu_
  prefix.
- MI wrapper functions critical_enter/exit maintain a per-thread nesting
  count and a per-thread critical section saved state set when entering
  a critical section while at nesting level 0 and restored when exiting
  to nesting level 0.  This moves the saved state out of spin mutexes so
  that interlocking spin mutexes works properly.
- Most low-level MD code that used critical_enter/exit now use
  cpu_critical_enter/exit.  MI code such as device drivers and spin
  mutexes use the MI wrappers.  Note that since the MI wrappers store
  the state in the current thread, they do not have any return values or
  arguments.
- mtx_intr_enable() is replaced with a constant CRITICAL_FORK which is
  assigned to curthread->td_savecrit during fork_exit().

Tested on:	i386, alpha
2001-12-18 00:27:18 +00:00
John Baldwin
8e2e767b1f Add a per-thread ucred reference for syscalls and synchronous traps from
userland.  The per thread ucred reference is immutable and thus needs no
locks to be read.  However, until all the proc locking associated with
writes to p_ucred are completed, it is still not safe to use the per-thread
reference.

Tested on:	x86 (SMP), alpha, sparc64
2001-10-26 08:12:54 +00:00
John Baldwin
278da5113f Remove a bogus comment. "atomic" doesn't mean that the operation is done
as a physical atomic operation.  That would require the code to use the
atomic API, which it does not.  Instead, the operation is made psuedo
atomic (hence the quotes) by use of the lock to protect clearing all of the
flags in question.
2001-09-21 19:26:57 +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
Matthew Dillon
356861db03 Remove the MPSAFE keyword from the parser for syscalls.master.
Instead introduce the [M] prefix to existing keywords.  e.g.
MSTD is the MP SAFE version of STD.  This is prepatory for a
massive Giant lock pushdown.  The old MPSAFE keyword made
syscalls.master too messy.

Begin comments MP-Safe procedures with the comment:
/*
 * MPSAFE
 */
This comments means that the procedure may be called without
Giant held (The procedure itself may still need to obtain
Giant temporarily to do its thing).

sv_prepsyscall() is now MP SAFE and assumed to be MP SAFE
sv_transtrap() is now MP SAFE and assumed to be MP SAFE

ktrsyscall() and ktrsysret() are now MP SAFE (Giant Pushdown)
trapsignal() is now MP SAFE (Giant Pushdown)

Places which used to do the if (mtx_owned(&Giant)) mtx_unlock(&Giant)
test in syscall[2]() in */*/trap.c now do not.  Instead they
explicitly unlock Giant if they previously obtained it, and then
assert that it is no longer held to catch broken system calls.

Rebuild syscall tables.
2001-08-30 18:50:57 +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
Matthew Dillon
085be199c6 postsig() currently requires Giant to be held. Giant is held properly at
the first postsig() call, but not always held at the second place,
resulting in an occassional panic.
2001-07-04 15:36:30 +00:00
John Baldwin
64acb05b1c Grab Giant around postsig() since sendsig() can call into the vm to
grow the stack and we already needed Giant for KTRACE.
2001-07-03 05:27:53 +00:00
John Baldwin
7aa7260e4a Move ast() and userret() to sys/kern/subr_trap.c now that they are MI. 2001-06-29 19:51:37 +00:00
John Baldwin
6be523bca7 Add a new MI pointer to the process' trapframe p_frame instead of using
various differently named pointers buried under p_md.

Reviewed by:	jake (in principle)
2001-06-29 11:10:41 +00:00
John Baldwin
92809bc001 Grab Giant around trap_pfault() for now. 2001-06-29 04:18:10 +00:00
John Baldwin
06c836bbca - Grab the proc lock around CURSIG and postsig(). Don't release the proc
lock until after grabbing the sched_lock to avoid CURSIG racing with
  psignal.
- Don't grab Giant for addupc_task() as it isn't needed.

Reported by:	tegge (signal race), bde (addupc_task a while back)
2001-06-22 23:05:11 +00:00
John Baldwin
262c9f8a3b Don't hold sched_lock across addupc_task().
Reported by:	David Taylor <davidt@yadt.co.uk>
Submitted by:	bde
2001-06-06 00:57:24 +00:00
John Baldwin
0dfefe6829 Don't acquire Giant just to call trap_fatal(), we are about to panic
anyway so we'd rather see the printf's then block if the system is
hosed.
2001-05-23 22:58:09 +00:00
Bruce Evans
1c1771cb5b Convert npx interrupts into traps instead of vice versa. This is much
simpler for npx exceptions that start as traps (no assembly required...)
and works better for npx exceptions that start as interrupts (there is
no longer a problem for nested interrupts).

Submitted by:	original (pre-SMPng) version by luoqi
2001-05-22 21:20:49 +00:00
Alfred Perlstein
2395531439 Introduce a global lock for the vm subsystem (vm_mtx).
vm_mtx does not recurse and is required for most low level
vm operations.

faults can not be taken without holding Giant.

Memory subsystems can now call the base page allocators safely.

Almost all atomic ops were removed as they are covered under the
vm mutex.

Alpha and ia64 now need to catch up to i386's trap handlers.

FFS and NFS have been tested, other filesystems will need minor
changes (grabbing the vm lock when twiddling page properties).

Reviewed (partially) by: jake, jhb
2001-05-19 01:28:09 +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
1efb92b7ca Simplify the vm fault trap handling code a bit by using if-else instead of
duplicating code in the then case and then using a goto to jump around
the else case.
2001-05-11 23:50:08 +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
f227364a17 - Release Giant a bit earlier on syscall exit.
- Don't try to grab Giant before postsig() in userret() as it is no longer
  needed.
- Don't grab Giant before psignal() in ast() but get the proc lock instead.
2001-03-07 03:53:39 +00:00
Jake Burkholder
631d7bf3da - Rename the lcall system call handler from Xsyscall to Xlcall_syscall
to be more like Xint0x80_syscall and less like c function syscall().
- Reduce code duplication between the int0x80 and lcall handlers by
  shuffling the elfags into the right place, saving the sizeof the
  instruction in tf_err and jumping into the common int0x80 code.

Reviewed by:	peter
2001-02-25 02:53:06 +00:00
John Baldwin
feb43c5f37 The p_md.md_regs member of proc is used in signal handling to reference
the the original trapframe of the syscall, trap, or interrupt that entered
the kernel.  Before SMPng, ast's were handled via a psuedo trap at the
end of doerti.  With the SMPng commit, ast's were broken out into a
separate ast() function that was called from doreti to match the behavior
of other architectures.  Unfortunately, when this was done, the
p_md.md_regs member of curproc was not updateda in ast(), thus when
signals are handled by userret() after an interrupt that returns to
userland, we end up using a stale trapframe that will result in the
registers from the old trapframe overwriting the real trapframe and
smashing all the registers right before we return to usermode.  The saved
%cs:%eip from where we were in usermode are saved in the trapframe for
example.
2001-02-22 19:35:20 +00:00
John Baldwin
f308e0d714 - Change ast() to take a pointer to a trapframe like other architectures.
- Don't use an atomic operation to update cnt.v_soft in ast().  This is
  the only place the variable is written to, and sched_lock is always
  held when it is written, so it is already protected and the mutex release
  of sched_lock asserts a memory barrier that ensures the value will be
  updated in a timely fashion.
2001-02-22 18:05:15 +00:00
John Baldwin
26f9f5c7c7 - Use TRAPF_PC() on the alpha to acess the PC in the trap frame.
- Don't hold sched_lock around addupc_task() as this apparently breaks
  profiling badly due to sched_lock being held across copyin().

Reported by:	bde (2)
2001-02-22 16:23:12 +00:00
John Baldwin
5813dc03bd - Don't call clear_resched() in userret(), instead, clear the resched flag
in mi_switch() just before calling cpu_switch() so that the first switch
  after a resched request will satisfy the request.
- While I'm at it, move a few things into mi_switch() and out of
  cpu_switch(), specifically set the p_oncpu and p_lastcpu members of
  proc in mi_switch(), and handle the sched_lock state change across a
  context switch in mi_switch().
- Since cpu_switch() no longer handles the sched_lock state change, we
  have to setup an initial state for sched_lock in fork_exit() before we
  release it.
2001-02-20 05:26:15 +00:00
Bruce Evans
0ad74739ac Removed all traces of T_ASTFLT (except for gaps where it was). It became
unused except in dead code when ast() was split off from trap().
2001-02-19 15:47:38 +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
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
Bruce Evans
c1087c1324 Support compiling with `gcc -ansi'. 1998-04-15 17:47:40 +00:00
Poul-Henning Kamp
227ee8a188 Eradicate the variable "time" from the kernel, using various measures.
"time" wasn't a atomic variable, so splfoo() protection were needed
around any access to it, unless you just wanted the seconds part.

Most uses of time.tv_sec now uses the new variable time_second instead.

gettime() changed to getmicrotime(0.

Remove a couple of unneeded splfoo() protections, the new getmicrotime()
is atomic, (until Bruce sets a breakpoint in it).

A couple of places needed random data, so use read_random() instead
of mucking about with time which isn't random.

Add a new nfs_curusec() function.

Mark a couple of bogosities involving the now disappeard time variable.

Update ffs_update() to avoid the weird "== &time" checks, by fixing the
one remaining call that passwd &time as args.

Change profiling in ncr.c to use ticks instead of time.  Resolution is
the same.

Add new function "tvtohz()" to avoid the bogus "splfoo(), add time, call
hzto() which subtracts time" sequences.

Reviewed by:	bde
1998-03-30 09:56:58 +00:00
Bruce Evans
08637435f2 Moved some #includes from <sys/param.h> nearer to where they are actually
used.
1998-03-28 10:33:27 +00:00
Jonathan Lemon
640c4313af Add the ability to make real-mode BIOS calls from the kernel. Currently,
everything is contained inside #ifdef VM86, so this option must be
present in the config file to use this functionality.

Thanks to Tor Egge, these changes should work on SMP machines.  However,
it may not be throughly SMP-safe.

Currently, the only BIOS calls made are memory-sizing routines at bootup,
these replace reading the RTC values.
1998-03-23 19:52:59 +00:00
Eivind Eklund
0b08f5f737 Back out DIAGNOSTIC changes. 1998-02-06 12:14:30 +00:00
Eivind Eklund
47cfdb166d Turn DIAGNOSTIC into a new-style option. 1998-02-04 22:34:03 +00:00
Eivind Eklund
e0d781f3a5 Make POWERFAIL_NMI, PPS_SYNC and NATM new style options.
This also fixes a couple of defunct options; submitted by bde.
1998-01-31 05:00:21 +00:00
Sean Eric Fagan
2a024a2b05 Changes to allow event-based process monitoring and control. 1997-12-06 04:11:14 +00:00
John-Mark Gurney
4d9deedb49 document and make the NO_F00F_HACK a proper option...
also, sort some option includes while I'm here..

Forgotten by:	sef
1997-12-04 21:21:26 +00:00
Jordan K. Hubbard
e41b6f2db7 After consultation with David, change
#ifndef NO_F00F_HACK
to
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
1997-12-04 14:35:40 +00:00
Sean Eric Fagan
c4fbf2774d Work around for the Intel Pentium F00F bug; this is Intel's recommended
workaround.  Note that this currently eats up two pages extra in the system;
this could be alleviated by aligning idt correctly, and then only dealing with
that (as opposed to the current method of allocated two pages and copying the
IDT table to that, and then setting that to be the IDT table).
1997-12-03 02:45:50 +00:00
Bruce Evans
21e5241572 Fixed some #include messes.
Hid the check of the user %cs in syscall() under `#ifdef DIAGNOSTIC'.
1997-11-24 13:25:37 +00:00
Poul-Henning Kamp
cb226aaa62 Move the "retval" (3rd) parameter from all syscall functions and put
it in struct proc instead.

This fixes a boatload of compiler warning, and removes a lot of cruft
from the sources.

I have not removed the /*ARGSUSED*/, they will require some looking at.

libkvm, ps and other userland struct proc frobbing programs will need
recompiled.
1997-11-06 19:29:57 +00:00
Peter Wemm
b67dffdad2 Compensate for pcb.h tweaks.
(Bruce pointed out the nesting)
1997-10-10 12:42:54 +00:00
Peter Wemm
98823b2366 Convert the VM86 option from a global option to an option only depended
on by the files that use it.  Changing the VM86 option now only causes
a recompile of a dozen files or so rather than the entire kernel.
1997-10-10 09:44:12 +00:00
Justin T. Gibbs
919429034e autoconf.c:
Add cpu_rootconf and cpu_dumpconf so that configuring these
	two devices can be better controlled by the MI configuration
	code.

machdep.c:
	MD initialization code for the new callout interface.

trap.c:
	Add support for printing out whether cam interrupts are masked
	during a panic.
1997-09-21 21:38:05 +00:00
Peter Wemm
279a69322c Cosmetic adjustment for the trap/double fault/panic cpu id listing.
It now prints the apic id in hex rather than decimal.
1997-09-05 08:54:55 +00:00
Jonathan Lemon
5f07393373 Remove the vm86 support as an LKM, and link it directly into the kernel
if 'options "VM86"' is in the config file.  The LKM was really for
development, and has probably outlived its usefulness.
1997-08-28 14:36:56 +00:00
Peter Wemm
9a3b3e8bce Clean up the SMP AP bootstrap and eliminate the wretched idle procs.
- We now have enough per-cpu idle context, the real idle loop has been
revived (cpu's halt now with nothing to do).
- Some preliminary support for running some operations outside the
global lock (eg: zeroing "free but not yet zeroed pages") is present
but appears to cause problems.  Off by default.
- the smp_active sysctl now behaves differently. It's merely a 'true/false'
option.  Setting smp_active to zero causes the AP's to halt in the idle
loop and stop scheduling processes.
- bootstrap is a lot safer.  Instead of sharing a statically compiled in
stack a number of times (which has caused lots of problems) and then
abandoning it, we use the idle context to boot the AP's directly.  This
should help >2 cpu support since the bootlock stuff was in doubt.
- print physical apic id in traps.. helps identify private pages getting
out of sync.  (You don't want to know how much hair I tore out with this!)

More cleanup to follow, this is more of a checkpoint than a
'finished' thing.
1997-08-26 18:10:38 +00:00
Philippe Charnier
40d5099441 Revert my previous commit about using CS_SECURE macro.
Requested by:	Bruce.
1997-08-21 06:33:04 +00:00
Steve Passe
7b185ef809 Preperation for moving cpl into critical region access.
Several new fine-grained locks.
New FAST_INTR() methods:
 - separate simplelock for FAST_INTR, no more giant lock.
 - FAST_INTR()s no longer checks ipending on way out of ISR.
sio made MP-safe (I hope).
1997-08-20 05:25:48 +00:00
Philippe Charnier
15f3549108 Use CS_SECURE macro.
Reviewed by:	John Dyson
1997-08-18 06:58:59 +00:00
John Dyson
0b6e0f74f9 Back out a part of the disk scheduling "improvements" :-(. Let me know
how the system works now!!!
1997-08-12 19:07:42 +00:00
John Dyson
c0ecffb96b Modify the scheduling policy to take into account disk I/O waits
as chargeable CPU usage.  This should mitigate the problem of processes
doing disk I/O hogging the CPU.  Various users have reported the
problem, and test code shows that the problem should now be gone.
1997-08-09 10:13:32 +00:00
John Dyson
48a09cf276 VM86 kernel support.
Work done by BSDI, Jonathan Lemon <jlemon@americantv.com>,
	Mike Smith <msmith@gsoft.com.au>, Sean Eric Fagan <sef@kithrup.com>,
	and probably alot of others.
Submitted by:	Jnathan Lemon <jlemon@americantv.com>
1997-08-09 00:04:06 +00:00
Bruce Evans
e31521c3dd Removed unused #includes. 1997-07-20 08:37:24 +00:00
Peter Wemm
b3196e4b9f Preliminary support for per-cpu data pages.
This eliminates a lot of #ifdef SMP type code.  Things like _curproc reside
in a data page that is unique on each cpu, eliminating the expensive macros
like:    #define curproc (SMPcurproc[cpunumber()])

There are some unresolved bootstrap and address space sharing issues at
present, but Steve is waiting on this for other work.  There is still some
strictly temporary code present that isn't exactly pretty.

This is part of a larger change that has run into some bumps, this part is
standalone so it should be safe.  The temporary code goes away when the
full idle cpu support is finished.

Reviewed by: fsmp, dyson
1997-06-22 16:04:22 +00:00
Bruce Evans
7b3c84247b Preserve %fs and %gs across context switches. This has a relatively low
cost since it is only done in cpu_switch(), not for every exception.
The extra state is kept in the pcb, and handled much like the npx state,
with similar deficiencies (the state is not preserved across signal
handlers, and error handling loses state).
1997-06-07 04:36:10 +00:00
Doug Rabson
683523378c Move interrupt handling code from isa.c to a new file. This should make
isa.c (slightly) more portable and will make my life developing the really
portable version much easier.

Reviewed by:	peter, fsmp
1997-06-02 08:19:06 +00:00
Peter Wemm
5400ed3b2f Include file updates.. <machine/spl.h> -> <machine/ipl.h>, add
<machine/ipl.h> to those files that were depending on getting SWI_*
implicitly via <machine/cpufunc.h>
1997-05-31 09:27:31 +00:00
Peter Wemm
ae9249615f remove opt_smp.h and fix the reason it was needed. 1997-05-29 05:04:30 +00:00
Peter Wemm
835834c085 md_regs is now a struct trapframe * 1997-05-07 20:08:53 +00:00
John Dyson
b332d9a66e Make sure that *fork() always returns with %edx == 1 in the
child.  This was sometimes not happening correctly during my
threads code work.
1997-05-05 04:08:12 +00:00
Peter Wemm
477a642cee Man the liferafts! Here comes the long awaited SMP -> -current merge!
There are various options documented in i386/conf/LINT, there is more to
come over the next few days.

The kernel should run pretty much "as before" without the options to
activate SMP mode.

There are a handful of known "loose ends" that need to be fixed, but
have been put off since the SMP kernel is in a moderately good condition
at the moment.

This commit is the result of the tinkering and testing over the last 14
months by many people.  A special thanks to Steve Passe for implementing
the APIC code!
1997-04-26 11:46:25 +00:00
Bruce Evans
58611a61ed Fixed printing of registers in dbflalt_handler(). The registers
were always in a tss; that tss just changed from the one in the
pcb to common_tss (who knows where it was when there was no curpcb?).
Not using the pcb also fixed the problem that there is no pcb in
idle(), so we now always get useful register values.
1997-04-14 13:52:52 +00:00
Peter Wemm
a2a1c95c10 The biggie: Get rid of the UPAGES from the top of the per-process address
space. (!)

Have each process use the kernel stack and pcb in the kvm space.  Since
the stacks are at a different address, we cannot copy the stack at fork()
and allow the child to return up through the function call tree to return
to user mode - create a new execution context and have the new process
begin executing from cpu_switch() and go to user mode directly.
In theory this should speed up fork a bit.

Context switch the tss_esp0 pointer in the common tss.  This is a lot
simpler since than swithching the gdt[GPROC0_SEL].sd.sd_base pointer
to each process's tss since the esp0 pointer is a 32 bit pointer, and the
sd_base setting is split into three different bit sections at non-aligned
boundaries and requires a lot of twiddling to reset.

The 8K of memory at the top of the process space is now empty, and unmapped
(and unmappable, it's higher than VM_MAXUSER_ADDRESS).

Simplity the pmap code to manage process contexts, we no longer have to
double map the UPAGES, this simplifies and should measuably speed up fork().

The following parts came from John Dyson:

Set PG_G on the UPAGES that are now in kernel context, and invalidate
them when swapping them out.

Move the upages object (upobj) from the vmspace to the proc structure.

Now that the UPAGES (pcb and kernel stack) are out of user space, make
rfork(..RFMEM..) do what was intended by sharing the vmspace
entirely via reference counting rather than simply inheriting the mappings.
1997-04-07 07:16:06 +00:00
Peter Wemm
271b264e4c No longer use an i386tss as the basis of our pcb - it wasn't particularly
convenient and makes life difficult for my next commit.  We still need
an i386tss to point to for the tss slot in the gdt, so we use a common
tss shared between all processes.

Note that this is going to break debugging until this series of commits
is finished.  core dumps will change again too. :-(  we really need
a more modern core dump format that doesn't depend on the pcb/upages.

This change makes VM86 mode harder, but the following commits will remove
a lot of constraints for the VM86 system, including the possibility of
extending the pcb for an IO port map etc.

Obtained from: bde
1997-04-07 06:45:18 +00:00
John Dyson
a04c970a7a Fix the gdb executable modify problem. Thanks to the detective work
by Alan Cox <alc@cs.rice.edu>, and his description of the problem.

The bug was primarily in procfs_mem, but the mistake likely happened
due to the lack of vm system support for the operation.  I added
better support for selective marking of page dirty flags so that
vm_map_pageable(wiring) will not cause this problem again.

The code in procfs_mem is now less bogus (but maybe still a little
so.)
1997-04-06 02:29:45 +00:00
Peter Wemm
6875d25465 Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.
1997-02-22 09:48:43 +00:00
John Dyson
996c772f58 This is the kernel Lite/2 commit. There are some requisite userland
changes, so don't expect to be able to run the kernel as-is (very well)
without the appropriate Lite/2 userland changes.

The system boots and can mount UFS filesystems.

Untested: ext2fs, msdosfs, NFS
Known problems: Incorrect Berkeley ID strings in some files.
		Mount_std mounts will not work until the getfsent
		library routine is changed.

Reviewed by:	various people
Submitted by:	Jeffery Hsu <hsu@freebsd.org>
1997-02-10 02:22:35 +00:00
John Dyson
7e64cb7a96 Remove some dead code from trapwrite.
Submitted by:	Stephen McKay <syssgm@devetir.qld.gov.au>
1997-01-23 01:30:59 +00:00
Jordan K. Hubbard
1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00
Bruce Evans
959c02787e Only handle copyin/out/etc faults when not in an interrupt handler.
This makes unexpected faults (in an interrupt handler) more likely
to crash properly.  It could be done even better (more robustly and
more efficiently) using lazy fault handling.
1996-12-18 19:12:01 +00:00
Bruce Evans
f313170d3c Updated #includes to 4.4Lite style. 1996-09-10 08:32:01 +00:00
David Greenman
eaed89032e Change an splclock that needs to be an splhigh into an splhigh.
Reviewed by:	bde
1996-09-01 10:10:12 +00:00
David Greenman
11282a57ce Add support for i686 machine check trap. 1996-08-11 17:41:25 +00:00
Bruce Evans
f3460ead96 Fixed cloned comments about npx traps to match context. 1996-07-12 06:03:14 +00:00
Bruce Evans
79df6d8597 trap.c:
Fixed profiling of system times.  It was pre-4.4Lite and didn't support
statclocks.  System times were too small by a factor of 8.

Handle deferred profiling ticks the 4.4Lite way: use addupc_task() instead
of addupc().  Call addupc_task() directly instead of using the ADDUPC()
macro.

Removed vestigial support for PROFTIMER.

switch.s:
Removed addupc().

resourcevar.h:
Removed ADDUPC() and declarations of addupc().

cpu.h:
Updated a comment.  i386's never were tahoe's, and the deferred profiling
tick became (possibly) multiple ticks in 4.4Lite.

Obtained from:	mostly from NetBSD
1996-06-25 20:02:16 +00:00
Satoshi Asami
d7629dff3b A fast memory copy for Pentiums using floating point registers.
It is called from copyin and copyout.

The new routine is conditioned on I586_CPU and I586_FAST_BCOPY, so you
need

options "I586_FAST_BCOPY"

(quotes essenstial) in your kernel config file.

Also, if you have other kernel types configured in your kernel, an
additional check to make sure it is running on a Pentium is inserted.
(It is not clear why it doesn't help on P6s, it may be just that the
 Orion chipset doesn't prefetch as efficiently as Tritons and friends.)

Bruce can now hack this away. :)
1996-06-13 07:17:21 +00:00
Gary Palmer
c23670e294 Clean up -Wunused warnings.
Reviewed by:		bde
1996-06-12 05:11:41 +00:00
John Dyson
b18bfc3da7 This set of commits to the VM system does the following, and contain
contributions or ideas from Stephen McKay <syssgm@devetir.qld.gov.au>,
Alan Cox <alc@cs.rice.edu>, David Greenman <davidg@freebsd.org> and me:

	More usage of the TAILQ macros.  Additional minor fix to queue.h.
	Performance enhancements to the pageout daemon.
		Addition of a wait in the case that the pageout daemon
		has to run immediately.
		Slightly modify the pageout algorithm.
	Significant revamp of the pmap/fork code:
		1) PTE's and UPAGES's are NO LONGER in the process's map.
		2) PTE's and UPAGES's reside in their own objects.
		3) TOTAL elimination of recursive page table pagefaults.
		4) The page directory now resides in the PTE object.
		5) Implemented pmap_copy, thereby speeding up fork time.
		6) Changed the pv entries so that the head is a pointer
		   and not an entire entry.
		7) Significant cleanup of pmap_protect, and pmap_remove.
		8) Removed significant amounts of machine dependent
		   fork code from vm_glue.  Pushed much of that code into
		   the machine dependent pmap module.
		9) Support more completely the reuse of already zeroed
		   pages (Page table pages and page directories) as being
		   already zeroed.
	Performance and code cleanups in vm_map:
		1) Improved and simplified allocation of map entries.
		2) Improved vm_map_copy code.
		3) Corrected some minor problems in the simplify code.
	Implemented splvm (combo of splbio and splimp.)  The VM code now
		seldom uses splhigh.
	Improved the speed of and simplified kmem_malloc.
	Minor mod to vm_fault to avoid using pre-zeroed pages in the case
		of objects with backing objects along with the already
		existant condition of having a vnode.  (If there is a backing
		object, there will likely be a COW...  With a COW, it isn't
		necessary to start with a pre-zeroed page.)
	Minor reorg of source to perhaps improve locality of ref.
1996-05-18 03:38:05 +00:00
John Dyson
4e489ec421 Remove a now unnecessary prototype from pmap.c. Also remove now
unnecessary vm_fault's of page table pages in trap.c.
1996-03-28 05:40:58 +00:00
Bruce Evans
ba00d77a82 Print stack pointer and frame pointer in trap messages.
Fixed "trace/trap" message.

Reviewed by:	davidg
1996-03-27 17:33:39 +00:00
Peter Wemm
d66a506616 Mega-commit for Linux emulator update.. This has been stress tested under
netscape-2.0 for Linux running all the Java stuff.  The scrollbars are now
working, at least on my machine. (whew! :-)

I'm uncomfortable with the size of this commit, but it's too
inter-dependant to easily seperate out.

The main changes:

COMPAT_LINUX is *GONE*.  Most of the code has been moved out of the i386
machine dependent section into the linux emulator itself.  The int 0x80
syscall code was almost identical to the lcall 7,0 code and a minor tweak
allows them to both be used with the same C code.  All kernels can now
just modload the lkm and it'll DTRT without having to rebuild the kernel
first.  Like IBCS2, you can statically compile it in with "options LINUX".

A pile of new syscalls implemented, including getdents(), llseek(),
readv(), writev(), msync(), personality().  The Linux-ELF libraries want
to use some of these.

linux_select() now obeys Linux semantics, ie: returns the time remaining
of the timeout value rather than leaving it the original value.

Quite a few bugs removed, including incorrect arguments being used in
syscalls..  eg:  mixups between passing the sigset as an int, vs passing
it as a pointer and doing a copyin(), missing return values, unhandled
cases, SIOC* ioctls, etc.

The build for the code has changed.  i386/conf/files now knows how
to build linux_genassym and generate linux_assym.h on the fly.

Supporting changes elsewhere in the kernel:

The user-mode signal trampoline has moved from the U area to immediately
below the top of the stack (below PS_STRINGS).  This allows the different
binary emulations to have their own signal trampoline code (which gets rid
of the hardwired syscall 103 (sigreturn on BSD, syslog on Linux)) and so
that the emulator can provide the exact "struct sigcontext *" argument to
the program's signal handlers.

The sigstack's "ss_flags" now uses SS_DISABLE and SS_ONSTACK flags, which
have the same values as the re-used SA_DISABLE and SA_ONSTACK which are
intended for sigaction only.  This enables the support of a SA_RESETHAND
flag to sigaction to implement the gross SYSV and Linux SA_ONESHOT signal
semantics where the signal handler is reset when it's triggered.

makesyscalls.sh no longer appends the struct sysentvec on the end of the
generated init_sysent.c code.  It's a lot saner to have it in a seperate
file rather than trying to update the structure inside the awk script. :-)

At exec time, the dozen bytes or so of signal trampoline code are copied
to the top of the user's stack, rather than obtaining the trampoline code
the old way by getting a clone of the parent's user area.  This allows
Linux and native binaries to freely exec each other without getting
trampolines mixed up.
1996-03-02 19:38:20 +00:00
John Dyson
3eb77c8302 Fix a problem with tracking the modified bit. Eliminate the
ugly inline-asm code, and speed up the page-table-page tracking.
1996-02-25 03:02:53 +00:00