Commit Graph

67 Commits

Author SHA1 Message Date
John Baldwin
c06394f53f Use the KTR_LOCK mask for logging events via KTR in lockmgr() rather
than KTR_LOCKMGR.  lockmgr locks are locks just like other locks.
2003-03-11 20:00:37 +00:00
John Baldwin
263067951a Replace calls to WITNESS_SLEEP() and witness_list() with equivalent calls
to WITNESS_WARN().
2003-03-04 21:03:05 +00:00
Jeff Roberson
17661e5ac4 - Add an interlock argument to BUF_LOCK and BUF_TIMELOCK.
- Remove the buftimelock mutex and acquire the buf's interlock to protect
   these fields instead.
 - Hold the vnode interlock while locking bufs on the clean/dirty queues.
   This reduces some cases from one BUF_LOCK with a LK_NOWAIT and another
   BUF_LOCK with a LK_TIMEFAIL to a single lock.

Reviewed by:	arch, mckusick
2003-02-25 03:37:48 +00:00
Jeff Roberson
5e8feb5bed - Add a WITNESS_SLEEP() for the appropriate cases in lockmgr(). 2003-02-16 10:39:49 +00:00
Julian Elischer
822ded67fe The lockmanager has to keep track of locks per thread, not per process.
Submitted by:	david Xu (davidxu@)
Reviewed by:	jhb@
2003-02-05 19:36:58 +00:00
Julian Elischer
6f8132a867 Reversion of commit by Davidxu plus fixes since applied.
I'm not convinced there is anything major wrong with the patch but
them's the rules..

I am using my "David's mentor" hat to revert this as he's
offline for a while.
2003-02-01 12:17:09 +00:00
David Xu
0dbb100b9b Move UPCALL related data structure out of kse, introduce a new
data structure called kse_upcall to manage UPCALL. All KSE binding
and loaning code are gone.

A thread owns an upcall can collect all completed syscall contexts in
its ksegrp, turn itself into UPCALL mode, and takes those contexts back
to userland. Any thread without upcall structure has to export their
contexts and exit at user boundary.

Any thread running in user mode owns an upcall structure, when it enters
kernel, if the kse mailbox's current thread pointer is not NULL, then
when the thread is blocked in kernel, a new UPCALL thread is created and
the upcall structure is transfered to the new UPCALL thread. if the kse
mailbox's current thread pointer is NULL, then when a thread is blocked
in kernel, no UPCALL thread will be created.

Each upcall always has an owner thread. Userland can remove an upcall by
calling kse_exit, when all upcalls in ksegrp are removed, the group is
atomatically shutdown. An upcall owner thread also exits when process is
in exiting state. when an owner thread exits, the upcall it owns is also
removed.

KSE is a pure scheduler entity. it represents a virtual cpu. when a thread
is running, it always has a KSE associated with it. scheduler is free to
assign a KSE to thread according thread priority, if thread priority is changed,
KSE can be moved from one thread to another.

When a ksegrp is created, there is always N KSEs created in the group. the
N is the number of physical cpu in the current system. This makes it is
possible that even an userland UTS is single CPU safe, threads in kernel still
can execute on different cpu in parallel. Userland calls kse_create to add more
upcall structures into ksegrp to increase concurrent in userland itself, kernel
is not restricted by number of upcalls userland provides.

The code hasn't been tested under SMP by author due to lack of hardware.

Reviewed by: julian
2003-01-26 11:41:35 +00:00
Kirk McKusick
c6964d3bc9 Remove a race condition / deadlock from snapshots. When
converting from individual vnode locks to the snapshot
lock, be sure to pass any waiting processes along to the
new lock as well. This transfer is done by a new function
in the lock manager, transferlockers(from_lock, to_lock);
Thanks to Lamont Granquist <lamont@scriptkiddie.org> for
his help in pounding on snapshots beyond all reason and
finding this deadlock.

Sponsored by:   DARPA & NAI Labs.
2002-11-30 19:00:51 +00:00
Kirk McKusick
3a096f6c09 Have lockinit() initialize the debugging fields of a lock
when DEBUG_LOCKS is defined.

Sponsored by:	DARPA & NAI Labs.
2002-10-18 01:34:10 +00:00
Bruce Evans
8302d183f3 Include <sys/lockmgr.h> for the definitions of the locking interfaces that
are implemented here instead of depending on namespace pollution in
<sys/lock.h>.  Fixed nearby include messes (1 disordered include and 1
unused include).
2002-08-27 09:59:47 +00:00
Philippe Charnier
93b0017f88 Replace various spelling with FALLTHROUGH which is lint()able 2002-08-25 13:23:09 +00:00
Jeff Roberson
7181624aaa Record the file, line, and pid of the last successful shared lock holder. This
is useful as a last effort in debugging file system deadlocks.  This is enabled
via 'options DEBUG_LOCKS'
2002-05-30 05:55:22 +00:00
John Baldwin
6008862bc2 Change callers of mtx_init() to pass in an appropriate lock type name. In
most cases NULL is passed, but in some cases such as network driver locks
(which use the MTX_NETWORK_LOCK macro) and UMA zone locks, a name is used.

Tested on:	i386, alpha, sparc64
2002-04-04 21:03:38 +00:00
Eivind Eklund
04858e7ee4 Change wmesg to const char * instead of char * 2002-03-05 17:45:12 +00:00
Matthew Dillon
23b590188f Fix a BUF_TIMELOCK race against BUF_LOCK and fix a deadlock in vget()
against VM_WAIT in the pageout code.  Both fixes involve adjusting
the lockmgr's timeout capability so locks obtained with timeouts do not
interfere with locks obtained without a timeout.

Hopefully MFC: before the 4.5 release
2001-12-20 22:42:27 +00:00
Matthew Dillon
f286003909 Create a mutex pool API for short term leaf mutexes.
Replace the manual mutex pool in kern_lock.c (lockmgr locks) with the new API.
Replace the mutexes embedded in sxlocks with the new API.
2001-11-13 21:55:13 +00:00
John Baldwin
61d80e90a9 Add missing includes of sys/ktr.h. 2001-10-11 17:53:43 +00:00
John Baldwin
6a40eccec3 Malloc mutexes pre-zero'd as random garbage (including 0xdeadcode) my
trigget the check to make sure we don't initalize a mutex twice.
2001-10-10 20:43:50 +00:00
John Baldwin
bce9841972 Fix locking on td_flags for TDF_DEADLKTREAT. If the comments in the code
are true that curthread can change during this function, then this flag
needs to become a KSE flag, not a thread flag.
2001-09-13 22:33:37 +00:00
Julian Elischer
b40ce4165d KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

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

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

X-MFC after:    ha ha ha ha
2001-09-12 08:38:13 +00:00
John Baldwin
3f085c228e If we've panic'd already, then just bail in lockmgr rather than blocking or
possibly panic'ing again.
2001-08-10 23:29:15 +00:00
Alfred Perlstein
6157b69f4a Instead of asserting that a mutex is not still locked after unlocking it,
assert that the mutex is owned and not recursed prior to unlocking it.

This should give a clearer diagnostic when a programming error is caught.
2001-04-28 12:11:01 +00:00
Alfred Perlstein
98689e1e70 Assert that when using an interlock mutex it is not recursed when lockmgr()
is called.

Ok'd by: jhb
2001-04-20 22:38:40 +00:00
Alfred Perlstein
1375ed7eb7 convert if/panic -> KASSERT, explain what triggered the assertion 2001-04-13 10:15:53 +00:00
Jake Burkholder
1681b00a79 Fix a precedence bug. ! has higher precedence than &. 2001-04-08 04:15:26 +00:00
John Baldwin
635962afdf Proc locking. 2001-02-09 16:27:41 +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
Jason Evans
1b367556b5 Convert all simplelocks to mutexes and remove the simplelock implementations. 2001-01-24 12:35:55 +00:00
Jason Evans
d1c1b8413e Remove MUTEX_DECLARE() and MTX_COLD. Instead, postpone full mutex
initialization until after malloc() is safe to call, then iterate through
all mutexes and complete their initialization.

This change is necessary in order to avoid some circular bootstrapping
dependencies.
2001-01-21 07:52:20 +00:00
Jake Burkholder
96fde7da19 Use msleep instead of mtx_exit; tsleep; mtx_enter, which is not safe. 2000-12-01 02:18:38 +00:00
John Baldwin
d8881ca31d - machine/mutex.h -> sys/mutex.h
- The initial lock_mtx mutex used in the lockmgr code is initialized very
  early, so use MUTEX_DECLARE() and MTX_COLD.
2000-10-20 07:28:00 +00:00
Jason Evans
9722d88fba For lockmgr mutex protection, use an array of mutexes that are allocated
and initialized during boot.  This avoids bloating sizeof(struct lock).
As a side effect, it is no longer necessary to enforce the assumtion that
lockinit()/lockdestroy() calls are paired, so the LK_VALID flag has been
removed.

Idea taken from:	BSD/OS.
2000-10-12 22:37:28 +00:00
Jason Evans
a18b1f1d4d Convert lockmgr locks from using simple locks to using mutexes.
Add lockdestroy() and appropriate invocations, which corresponds to
lockinit() and must be called to clean up after a lockmgr lock is no
longer needed.
2000-10-04 01:29:17 +00:00
Paul Saab
92b123a002 Move MAXCPU from machine/smp.h to machine/param.h to fix breakage
with !SMP kernels.  Also, replace NCPUS with MAXCPU since they are
redundant.
2000-09-23 12:18:06 +00:00
Poul-Henning Kamp
c866ec47e3 Make LINT compile. 2000-09-16 18:55:05 +00:00
Poul-Henning Kamp
db5f635acc Eliminate the undocumented, experimental, non-delivering and highly
dangerous MAX_PERF option.
2000-03-16 08:51:55 +00:00
Eivind Eklund
6bdfe06ad9 Lock reporting and assertion changes.
* lockstatus() and VOP_ISLOCKED() gets a new process argument and a new
  return value: LK_EXCLOTHER, when the lock is held exclusively by another
  process.
* The ASSERT_VOP_(UN)LOCKED family is extended to use what this gives them
* Extend the vnode_if.src format to allow more exact specification than
  locked/unlocked.

This commit should not do any semantic changes unless you are using
DEBUG_VFS_LOCKS.

Discussed with:	grog, mch, peter, phk
Reviewed by:	peter
1999-12-11 16:13:02 +00:00
Alan Cox
99c9d3490b Correct a locking error in apause: It should always hold
the simple lock when it returns.

Also, eliminate spinning on a uniprocessor.  It's pointless.

Submitted by:	bde,
		Assar Westerlund <assar@sics.se>
1999-11-11 03:02:03 +00:00
Matthew Dillon
e701df7d61 Fix process p_locks accounting. Conversions of the owner to LK_KERNPROC
caused p_locks to be improperly accounted.

Submitted by:	Tor.Egge@fast.no
1999-09-27 00:21:43 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Kirk McKusick
33638e9384 When requesting an exclusive lock with LK_NOWAIT, do not panic
if LK_RECURSIVE is not set, as we will simply return that the
lock is busy and not actually deadlock. This allows processes
to use polling locks against buffers that they may already
hold exclusively locked.
1999-06-28 07:54:58 +00:00
Kirk McKusick
67812eacd7 Convert buffer locking from using the B_BUSY and B_WANTED flags to using
lockmgr locks. This commit should be functionally equivalent to the old
semantics. That is, all buffer locking is done with LK_EXCLUSIVE
requests. Changes to take advantage of LK_SHARED and LK_RECURSIVE will
be done in future commits.
1999-06-26 02:47:16 +00:00
Julian Elischer
50d3b68c81 fix breakage for alphas.
Submitted by: Andrew Gallatin <gallatin@cs.duke.edu>
1999-03-15 05:11:27 +00:00
Julian Elischer
beef8a367c This solves a deadlock that can occur when read()ing into a file-mmap()
space. When doing this, it is possible to for another process to attempt
to get an exclusive lock on the vnode and deadlock the mmap/read
combination when the uiomove() call tries to obtain a second
shared lock on the vnode. There is still a potential deadlock
situation with write()/mmap().
Submitted by: Matt Dillon <dillon@freebsd.org>
Reviewed by: Luoqi Chen <luoqi@freebsd.org>
Delimmitted by tag PRE_MATT_MMAP_LOCK and POST_MATT_MMAP_LOCK
in kern/kern_lock.c kern/kern_subr.c
1999-03-12 03:09:29 +00:00
Eivind Eklund
15a1057c46 Add 'options DEBUG_LOCKS', which stores extra information in struct
lock, and add some macros and function parameters to make sure that
the information get to the point where it can be put in the lock
structure.

While I'm here, add DEBUG_VFS_LOCKS to LINT.
1999-01-20 14:49:12 +00:00
Eivind Eklund
219cbf59f2 KNFize, by bde. 1999-01-10 01:58:29 +00:00
Eivind Eklund
5526d2d920 Split DIAGNOSTIC -> DIAGNOSTIC, INVARIANTS, and INVARIANT_SUPPORT as
discussed on -hackers.

Introduce 'KASSERT(assertion, ("panic message", args))' for simple
check + panic.

Reviewed by:	msmith
1999-01-08 17:31:30 +00:00
Eivind Eklund
9fcdafaefc Staticize. 1998-11-26 18:50:24 +00:00
Bruce Evans
ab36c3d3e7 Really finish supporting compiling with `gcc -ansi'. 1998-04-17 04:53:44 +00:00
John Dyson
9b2e5bad34 Some kern_lock code improvements. Add missing wakeup, and enable
disabling some diagnostics when memory or speed is at a premium.
1998-03-07 19:25:34 +00:00