Commit Graph

151 Commits

Author SHA1 Message Date
Alan Cox
239b5b9707 o Setting PG_MAPPED and PG_WRITEABLE on pages that are mapped and unmapped
by pmap_qenter() and pmap_qremove() is pointless.  In fact, it probably
   leads to unnecessary pmap_page_protect() calls if one of these pages is
   paged out after unwiring.

Note: setting PG_MAPPED asserts that the page's pv list may be
non-empty.  Since checking the status of the page's pv list isn't any
harder than checking this flag, the flag should probably be eliminated.
Alternatively, PG_MAPPED could be set by pmap_enter() exclusively
rather than various places throughout the kernel.
2002-07-31 18:46:47 +00:00
Seigo Tanimura
9eb881f804 - Optimize wakeup() and its friends; if a thread waken up is being
swapped in, we do not have to ask for the scheduler thread to do
  that.

- Assert that a process is not swapped out in runq functions and
  swapout().

- Introduce thread_safetoswapout() for readability.

- In swapout_procs(), perform a test that may block (check of a
  thread working on its vm map) first.  This lets us call swapout()
  with the sched_lock held, providing a better atomicity.
2002-07-30 06:54:05 +00:00
Julian Elischer
b7f2cf173e Remove a XXXKSE comment. the code is no longer a problem.. 2002-07-29 18:47:19 +00:00
Julian Elischer
1d7b9ed2e6 Create a new thread state to describe threads that would be ready to run
except for the fact tha they are presently swapped out. Also add a process
flag to indicate that the process has started the struggle to swap
back in. This will be  needed for the case where multiple threads
start the swapin action top a collision. Also add code to stop
a process fropm being swapped out if one of the threads in this
process is actually off running on another CPU.. that might hurt...

Submitted by:	Seigo Tanimura <tanimura@r.dl.itc.u-tokyo.ac.jp>
2002-07-29 18:33:32 +00:00
Alan Cox
14f8ceaa07 o Pass VM_ALLOC_WIRED to vm_page_grab() rather than calling vm_page_wire()
in pmap_new_thread(), pmap_pinit(), and vm_proc_new().
 o Lock page queue accesses by vm_page_free() in pmap_object_init_pt().
2002-07-29 05:42:44 +00:00
Seigo Tanimura
1b64ed3b5b Do not pass a thread with the state TDS_RUNQ to setrunqueue(), otherwise
assertion in setrunqueue() fails.
2002-07-21 10:55:57 +00:00
Alan Cox
e16cfdbea4 o Lock page queue accesses by vm_page_wire(). 2002-07-14 19:36:15 +00:00
Alan Cox
2d09a6ad97 o Lock some page queue accesses, in particular, those by vm_page_unwire(). 2002-07-13 19:24:04 +00:00
Peter Wemm
a7e9138e37 Avoid a vm_page_lookup() - that uses a spinlock protected hash. We can
just use the object's memq for our nefarious purposes.
2002-07-12 04:38:51 +00:00
Peter Wemm
f59685a4b7 Avoid vm_page_lookup() [grabs a spinlock] and just process the upage
object memq instead.

Suggested by:	alc
2002-07-08 01:11:10 +00:00
Peter Wemm
a136efe9b6 Collect all the (now equivalent) pmap_new_proc/pmap_dispose_proc/
pmap_swapin_proc/pmap_swapout_proc functions from the MD pmap code
and use a single equivalent MI version.  There are other cleanups
needed still.

While here, use the UMA zone hooks to keep a cache of preinitialized
proc structures handy, just like the thread system does.  This eliminates
one dependency on 'struct proc' being persistent even after being freed.
There are some comments about things that can be factored out into
ctor/dtor functions if it is worth it.  For now they are mostly just
doing statistics to get a feel of how it is working.
2002-07-07 23:05:27 +00:00
Julian Elischer
8108a14544 A small cleanup. 2002-07-04 12:37:13 +00:00
Julian Elischer
a30ec8f8b8 Don;t call teh thread setup routines from here..
they are already called when uma calls thread_init()
2002-07-04 12:31:54 +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
Alan Cox
43a90f3a1b o Remove GIANT_REQUIRED from vslock().
o Annotate kernacc(), useracc(), and vslock() as MPSAFE.

Motivated by:	alfred
2002-06-22 01:26:02 +00:00
Alan Cox
319490fb7b o Remove GIANT_REQUIRED from useracc() and vsunlock(). Neither
vm_map_check_protection() nor vm_map_unwire() expect Giant
   to be held.
2002-06-15 19:10:19 +00:00
Alan Cox
1d7cf06c8c o Use vm_map_wire() and vm_map_unwire() in place of vm_map_pageable() and
vm_map_user_pageable().
 o Remove vm_map_pageable() and vm_map_user_pageable().
 o Remove vm_map_clear_recursive() and vm_map_set_recursive().  (They were
   only used by vm_map_pageable() and vm_map_user_pageable().)

Reviewed by:	tegge
2002-06-14 18:21:01 +00:00
Alan Cox
d974f03c69 o Introduce and use vm_map_trylock() to replace several direct uses
of lockmgr().
 o Add missing synchronization to vmspace_swap_count(): Obtain a read lock
   on the vm_map before traversing it.
2002-04-28 06:07:54 +00:00
Alfred Perlstein
11caded34f Remove __P. 2002-03-19 22:20:14 +00:00
Peter Wemm
30171114b3 Fix a gcc-3.1+ warning.
warning: deprecated use of label at end of compound statement

ie: you cannot do this anymore:
switch(foo) {
....

default:
}
2002-03-19 11:02:06 +00:00
Brian Feldman
25adb370be Back out the modification of vm_map locks from lockmgr to sx locks. The
best path forward now is likely to change the lockmgr locks to simple
sleep mutexes, then see if any extra contention it generates is greater
than removed overhead of managing local locking state information,
cost of extra calls into lockmgr, etc.

Additionally, making the vm_map lock a mutex and respecting it properly
will put us much closer to not needing Giant magic in vm.
2002-03-18 15:08:09 +00:00
Alan Cox
5ee9fe6ba1 Undo part of revision 1.57: Now that (o)sendsig() doesn't call useracc(),
the motivation for saving and restoring the map->hint in useracc() is gone.
(The same tests that motivated this change in revision 1.57 now show that
there is no performance loss from removing it.)  This was really a hack and
some day we would have had to add new synchronization here on map->hint
to maintain it.
2002-03-17 07:01:42 +00:00
Alan Cox
2f6c16e1e8 Acquire a read lock on the map inside of vm_map_check_protection() rather
than expecting the caller to do so.  This (1) eliminates duplicated code in
kernacc() and useracc() and (2) fixes missing synchronization in munmap().
2002-03-17 03:19:31 +00:00
Brian Feldman
0e0af8ecda Rename SI_SUB_MUTEX to SI_SUB_MTX_POOL to make the name at all accurate.
While doing this, move it earlier in the sysinit boot process so that the
VM system can use it.

After that, the system is now able to use sx locks instead of lockmgr
locks in the VM system.  To accomplish this, some of the more
questionable uses of the locks (such as testing whether they are
owned or not, as well as allowing shared+exclusive recursion) are
removed, and simpler logic throughout is used so locks should also be
easier to understand.

This has been tested on my laptop for months, and has not shown any
problems on SMP systems, either, so appears quite safe.  One more
user of lockmgr down, many more to go :)
2002-03-13 23:48:08 +00:00
Eivind Eklund
a128794977 - Remove a number of extra newlines that do not belong here according to
style(9)
- Minor space adjustment in cases where we have "( ", " )", if(), return(),
  while(), for(), etc.
- Add /* SYMBOL */ after a few #endifs.

Reviewed by:	alc
2002-03-10 21:52:48 +00:00
Peter Wemm
dd50331c0e Remove unused variable (td) 2002-02-26 01:01:37 +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
Julian Elischer
079b7badea Pre-KSE/M3 commit.
this is a low-functionality change that changes the kernel to access the main
thread of a process via the linked list of threads rather than
assuming that it is embedded in the process. It IS still embeded there
but remove all teh code that assumes that in preparation for the next commit
which will actually move it out.

Reviewed by: peter@freebsd.org, gallatin@cs.duke.edu, benno rice,
2002-02-07 20:58:47 +00:00
Alfred Perlstein
582ec34cd8 Fix a race with free'ing vmspaces at process exit when vmspaces are
shared.

Also introduce vm_endcopy instead of using pointer tricks when
initializing new vmspaces.

The race occured because of how the reference was utilized:
  test vmspace reference,
  possibly block,
  decrement reference

When sharing a vmspace between multiple processes it was possible
for two processes exiting at the same time to test the reference
count, possibly block and neither one free because they wouldn't
see the other's update.

Submitted by: green
2002-02-05 21:23:05 +00:00
Bruce Evans
e50f5c2e8d Don't declare vm_swapout() in the NO_SWAPPING case when it is not defined.
Fixed some style bugs.
2002-01-17 16:46:26 +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
Paul Saab
cbc89bfbfe Make MAXTSIZ, DFLDSIZ, MAXDSIZ, DFLSSIZ, MAXSSIZ, SGROWSIZ loader
tunable.

Reviewed by:	peter
MFC after:	2 weeks
2001-10-10 23:06:54 +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
Peter Wemm
eb30c1c0b9 Rip some well duplicated code out of cpu_wait() and cpu_exit() and move
it to the MI area.  KSE touched cpu_wait() which had the same change
replicated five ways for each platform.  Now it can just do it once.
The only MD parts seemed to be dealing with fpu state cleanup and things
like vm86 cleanup on x86.  The rest was identical.

XXX: ia64 and powerpc did not have cpu_throw(), so I've put a functional
stub in place.

Reviewed by:	jake, tmm, dillon
2001-09-10 04:28:58 +00:00
Matthew Dillon
54d9214595 whitespace / register cleanup 2001-07-04 19:00:13 +00:00
Matthew Dillon
0cddd8f023 With Alfred's permission, remove vm_mtx in favor of a fine-grained approach
(this commit is just the first stage).  Also add various GIANT_ macros to
formalize the removal of Giant, making it easy to test in a more piecemeal
fashion. These macros will allow us to test fine-grained locks to a degree
before removing Giant, and also after, and to remove Giant in a piecemeal
fashion via sysctl's on those subsystems which the authors believe can
operate without Giant.
2001-07-04 16:20:28 +00:00
John Baldwin
69a78d4666 Put the scheduler, vmdaemon, and pagedaemon kthreads back under Giant for
now.  The proc locking isn't actually safe yet and won't be until the proc
locking is finished.
2001-06-20 00:48:20 +00:00
John Baldwin
3a2189d451 - Lock the VM around the pmap_swapin_proc() call in faultin().
- Don't lock Giant in the scheduler() function except for when calling
  faultin().
- In swapout_procs(), lock the VM before the proccess to avoid a lock order
  violation.
- In swapout_procs(), release the allproc lock before calling swapout().
  We restart the process scan after swapping out a process.
- In swapout_procs(), un #if 0 the code to bump the vmspace reference count
  and lock the process' vm structures.  This bug was introduced by me and
  could result in the vmspace being free'd out from under a running
  process.
- Fix an old bug where the vmspace reference count was not free'd if we
  failed the swap_idle_threshold2 test.
2001-05-23 22:35:45 +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
ea7549540f - Use a timeout for the tsleep in scheduler() instead of having vmmeter()
wakeup proc0 by hand to enforce the timeout.
- When swapping out a process, keep the process locked via the proc lock
  from the first checks up until we clear PS_INMEM and set PS_SWAPPING in
  swapout().  The swapout() function now must be called with the proc lock
  held and releases it before returning.
- Comment out the code to attempt to lock a process' VM structures before
  swapping out.  It is broken in that it releases the lock after obtaining
  it.  If it does grab the lock, it needs to hand it off to swapout()
  instead of releasing it.  This can be revisisted when the VM is locked
  as this is a valid test to perform.  It also causes a lock order reversal
  for the time being, which is the immediate cause for temporarily
  disabling it.
2001-05-18 00:08:38 +00:00
John Baldwin
c96d52a913 - Use PROC_LOCK_ASSERT instead of a direct mtx_assert.
- Don't hold Giant in the swapper daemon while we walk the list of
  processes looking for a process to swap back in.
- Don't bother grabbing the sched_lock while checking a process' sleep
  time in swapout_procs() to ensure that a process has been idle for at
  least swap_idle_threshold2 before swapping it out.  If we lose the race
  we just let a process stay in memory until the next call of
  swapout_procs().
- Remove some unneeded spl's, sched_lock does all the locking needed in
  this case.
2001-05-15 22:20:44 +00:00
Mark Murray
fb919e4d5a Undo part of the tangle of having sys/lock.h and sys/mutex.h included in
other "system" header files.

Also help the deprecation of lockmgr.h by making it a sub-include of
sys/lock.h and removing sys/lockmgr.h form kernel .c files.

Sort sys/*.h includes where possible in affected files.

OK'ed by:	bde (with reservations)
2001-05-01 08:13:21 +00:00
John Baldwin
1005a129e5 Convert the allproc and proctree locks from lockmgr locks to sx locks. 2001-03-28 11:52:56 +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
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
45ece682fd - Doh, lock faultin() with proc lock in scheduler().
- Lock p_swtime with sched_lock in scheduler() as well.
2001-01-25 01:38:09 +00:00
John Baldwin
69b4045657 Argh, I didn't get this test right when I converted it. Break this up
into two separate if's instead of nested if's.  Also, reorder things
slightly to avoid unnecessary mutex operations.
2001-01-24 12:23:17 +00:00
John Baldwin
5074aecd6c - Catch up to proc flag changes.
- Proc locking in a few places.
- faultin() now must be called with the proc lock held.
- Split up swappable() into a couple of tests so that it can be locke in
  swapout_procs().
- Use queue macros.
2001-01-24 11:25:56 +00:00
Jake Burkholder
c0c2557090 - Change the allproc_lock to use a macro, ALLPROC_LOCK(how), instead
of explicit calls to lockmgr.  Also provides macros for the flags
  pased to specify shared, exclusive or release which map to the
  lockmgr flags.  This is so that the use of lockmgr can be easily
  replaced with optimized reader-writer locks.
- Add some locking that I missed the first time.
2000-12-13 00:17:05 +00:00
John Baldwin
c8a6b0011c Protect p_stat with sched_lock. 2000-12-02 03:29:33 +00:00