Commit Graph

15 Commits

Author SHA1 Message Date
jhb
22fc91da31 Convert the allproc and proctree locks from lockmgr locks to sx locks. 2001-03-28 11:52:56 +00:00
jhb
4b1f571f83 - Use _PHOLD and move it before a PROC_UNLOCK to reduce the number of
mutex operations in kthread_create().
- Lock a kthread's proc before changing its parent via proc_reparent().
- Test P_KTHREAD not P_SYSTEM in kthread_suspend() and kthread_resume().
  P_SYSTEM just means that the process shouldn't be swapped and is used
  for vinum's daemon for example.
- Lock all the signal state used for suspending and resuming kthreads with
  the proc lock.
2001-03-07 02:36:47 +00:00
bmilekic
e67bcfcaf3 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
jhb
6dc4c08ec1 - Catch up to proc flag changes.
- Set the new P_KTHREAD flag for kthreads during kthread_create.
2001-01-24 10:47:50 +00:00
jake
2a7c5bd038 Protect proc.p_pptr and proc.p_children/p_sibling with the
proctree_lock.

linprocfs not locked pending response from informal maintainer.

Reviewed by:	jhb, -smp@
2000-12-23 19:43:10 +00:00
jhb
172899a3ac Stick the kthread API in a kthread_* namespace, and the specialized kproc
functions in a kproc_* namespace.

Reviewed by:	-arch
2000-12-15 20:08:20 +00:00
jhb
102e2e4412 Pass RFSTOPPED to fork1() in kthread_create() to avoid a race condition
where fork1() could put the process on the run queue where it could be
snatched up by another CPU before kthread_create() had set the proper
fork handler.  Instead, we put the new kthread on the runqueue after its
fork handler has been sent.

Noticed by:	jake
Looked over by:	peter
2000-12-06 03:45:15 +00:00
jhb
1076772e76 Reparent a kernel thread to init during kthread_exit() so that the zombie
can be reaped.
2000-10-19 19:53:44 +00:00
jasone
daa58ba7a4 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
peter
b77a95e8cc Clean up some low level bootstrap code:
- stop using the evil 'struct trapframe' argument for mi_startup()
  (formerly main()).  There are much better ways of doing it.
- do not use prepare_usermode() - setregs() in execve() will do it
  all for us as long as the p_md.md_regs pointer is set.  (which is
  now done in machdep.c rather than init_main.c.  The Alpha port did it
  this way all along and is much cleaner).
- collect all the magic %cr0 etc register settings into one place and
  have the AP's call that instead of using magic numbers (!!) that keep
  changing over and over again.
- Make it safe to call kthread_create() earlier, including during the
  device probe sequence.  It doesn't need the callback mechanism that
  NetBSD's version uses.
- kthreads created this way are root-less as they exist before the root
  filesystem is mounted.  init(1) is set up so that it aquires the root
  pointers prior to running.  If other kthreads want filesystem acccess
  we can make this code more generic.
- set all threads start times once we have decided what time it is.
- init uses a trampoline rather than the evil prepare_usermode() hack.
- kern_descrip.c has a couple of tweaks to deal with forking when there
  is no rootdir or cwd etc.
- adjust the early SYSINIT() sequence so that a few prereqisites are in
  place. eg: make sure the run queue is initialized before doing forks.

With this, the USB code can easily create a kthread to do the device
tree discovery.  (I have tested it, it works nicely).

There are still some open issues before this is truely useful.
- tsleep() does not like working before the clock is running.  It
  sort-of tries to spin wait, but it can do more useful things now.
- stopping a kthread in kld code at unload time is "interesting" but
  we have a solution for that.

The Alpha code needs no changes for this.  It already uses pretty much the
same strategies, but a little cleaner.
2000-08-11 09:05:12 +00:00
imp
4b6e07c491 Panic if proc0 hasn't been created and we try to call kthread_create.
This prevents a more mysterious crash later.

XXX The long term solution is defer creation of these things until
XXX proc0 lives
2000-01-10 08:00:58 +00:00
luoqi
3a2a7a4b1c Introduce a mechanism to suspend/resume system processes. Suspend syncer
and bufdaemon prior to disk sync during system shutdown.
2000-01-07 08:36:44 +00:00
luoqi
4081a7f93f Add a per-signal flag to mark handlers registered with osigaction, so we
can provide the correct context to each signal handler.

Fix broken sigsuspend(): don't use p_oldsigmask as a flag, use SAS_OLDMASK
as we did before the linuxthreads support merge (submitted by bde).

Move ps_sigstk from to p_sigacts to the main proc structure since signal
stack should not be shared among threads.

Move SAS_OLDMASK and SAS_ALTSTACK flags from sigacts::ps_flags to proc::p_flag.
Move PS_NOCLDSTOP and PS_NOCLDWAIT flags from proc::p_flag to procsig::ps_flag.

Reviewed by:	marcel, jdp, bde
1999-10-11 20:33:17 +00:00
peter
5f2dea3689 Trim unused options (or #ifdef for undoc options).
Submitted by:	phk
1999-10-11 15:19:12 +00:00
peter
59391814b7 Slight reorganization of kernel thread/process creation. Instead of using
SYSINIT_KT() etc (which is a static, compile-time procedure), use a
NetBSD-style kthread_create() interface.  kproc_start is still available
as a SYSINIT() hook.  This allowed simplification of chunks of the
sysinit code in the process.  This kthread_create() is our old kproc_start
internals, with the SYSINIT_KT fork hooks grafted in and tweaked to work
the same as the NetBSD one.

One thing I'd like to do shortly is get rid of nfsiod as a user initiated
process.  It makes sense for the nfs client code to create them on the
fly as needed up to a user settable limit.  This means that nfsiod
doesn't need to be in /sbin and is always "available".  This is a fair bit
easier to do outside of the SYSINIT_KT() framework.
1999-07-01 13:21:46 +00:00