Commit Graph

110 Commits

Author SHA1 Message Date
jhb
f78df6dd24 Move lock_profile_object_{init,destroy}() into lock_{init,destroy}(). 2007-05-18 15:04:59 +00:00
jhb
0d7ad36cd0 - Use lock_init/lock_destroy() to setup the lock_object inside of lockmgr.
We can now use LOCK_CLASS() as a stronger check in lockmgr_chain() as a
  result.  This required putting back lk_flags as lockmgr's use of flags
  conflicted with other flags in lo_flags otherwise.
- Tweak 'show lock' output for lockmgr to match sx, rw, and mtx.
2007-03-30 18:07:24 +00:00
jhb
a84f74bb36 Rename the 'mtx_object', 'rw_object', and 'sx_object' members of mutexes,
rwlocks, and sx locks to 'lock_object'.
2007-03-21 21:20:51 +00:00
jhb
08da44e275 Handle the case when a thread is blocked on a lockmgr lock with LK_DRAIN
in DDB's 'show sleepchain'.

MFC after:	3 days
2007-03-21 19:28:20 +00:00
jhb
60ad130f46 Add two new function pointers 'lc_lock' and 'lc_unlock' to lock classes.
These functions are intended to be used to drop a lock and then reacquire
it when doing an sleep such as msleep(9).  Both functions accept a
'struct lock_object *' as their first parameter.  The 'lc_unlock' function
returns an integer that is then passed as the second paramter to the
subsequent 'lc_lock' function.  This can be used to communicate state.
For example, sx locks and rwlocks use this to indicate if the lock was
share/read locked vs exclusive/write locked.

Currently, spin mutexes and lockmgr locks do not provide working lc_lock
and lc_unlock functions.
2007-03-09 16:27:11 +00:00
jhb
f5f98a764d Use C99-style struct member initialization for lock classes. 2007-03-09 16:19:34 +00:00
kmacy
6508c4f27b general LOCK_PROFILING cleanup
- only collect timestamps when a lock is contested - this reduces the overhead
  of collecting profiles from 20x to 5x

- remove unused function from subr_lock.c

- generalize cnt_hold and cnt_lock statistics to be kept for all locks

- NOTE: rwlock profiling generates invalid statistics (and most likely always has)
  someone familiar with that should review
2007-02-26 08:26:44 +00:00
kmacy
ec9503cd04 track lock class name in a way that doesn't break WITNESS 2006-11-13 05:41:46 +00:00
kmacy
b082a8c58a show lock class in profiling output for default case where type is not specified when initializing the lock
Approved by: scottl (standing in for mentor rwatson)
2006-11-12 03:30:01 +00:00
kmacy
9eefcf3161 MUTEX_PROFILING has been generalized to LOCK_PROFILING. We now profile
wait (time waited to acquire) and hold times for *all* kernel locks. If
the architecture has a system synchronized TSC, the profiling code will
use that - thereby minimizing profiling overhead. Large chunks of profiling
code have been moved out of line, the overhead measured on the T1 for when
it is compiled in but not enabled is < 1%.

Approved by: scottl (standing in for mentor rwatson)
Reviewed by: des and jhb
2006-11-11 03:18:07 +00:00
tegge
4d26d3d4d7 If the buffer lock has waiters after the buffer has changed identity then
getnewbuf() needs to drop the buffer in order to wake waiters that might
sleep on the buffer in the context of the old identity.
2006-10-02 02:06:27 +00:00
jhb
4e96206d8a Add a new 'show sleepchain' ddb command similar to 'show lockchain' except
that it operates on lockmgr and sx locks.  This can be useful for tracking
down vnode deadlocks in VFS for example.  Note that this command is a bit
more fragile than 'show lockchain' as we have to poke around at the
wait channel of a thread to see if it points to either a struct lock or
a condition variable inside of a struct sx.  If td_wchan points to
something unmapped, then this command will terminate early due to a fault,
but no harm will be done.
2006-08-15 18:29:01 +00:00
jhb
9810a59f6d Add a 'show lockmgr' command that dumps the relevant details of a lockmgr
lock.
2006-08-15 16:42:16 +00:00
pjd
3bffd255ce Remove duplicated #include. 2006-07-14 17:55:36 +00:00
jeff
e2af894dc5 - Remove and unused include.
Submitted by:	Antoine Brodin <antoine.brodin@laposte.net>
2005-12-23 21:32:40 +00:00
rwatson
920951839a Include kdb.h so that kdb_active is declared regardless of KDB being
included in the kernel.

MFC after:	0 days
2005-10-02 10:03:51 +00:00
rwatson
b95808bd52 In lockstatus(), don't lock and unlock the interlock when testing the
sleep lock status while kdb_active, or we risk contending with the
mutex on another CPU, resulting in a panic when using "show
lockedvnods" while in DDB.

MFC after:	3 days
Reviewed by:	jhb
Reported by:	kris
2005-09-27 21:02:59 +00:00
ssouhlal
6dfa271942 Print out a warning and a backtrace if we try to unlock a lockmgr that
we do not hold.

Glanced at by:	phk
MFC after:	3 days
2005-09-02 15:56:01 +00:00
pjd
a520307ce1 Add 'depth' argument to CTRSTACK() macro, which allows to reduce number
of ktr slots used. If 'depth' is equal to 0, the whole stack will be
logged, just like before.
2005-08-29 11:34:08 +00:00
jeff
a2347b7b51 - Fix a problem that slipped through review; the stack member of the lockmgr
structure should have the lk_ prefix.
 - Add stack_print(lkp->lk_stack) to the information printed with
   lockmgr_printinfo().
2005-08-03 04:59:07 +00:00
jeff
08fb635b55 - Replace the series of DEBUG_LOCKS hacks which tried to save the vn_lock
caller by saving the stack of the last locker/unlocker in lockmgr.  We
   also put the stack in KTR at the moment.

Contributed by:		Antoine Brodin <antoine.brodin@laposte.net>
2005-08-03 04:48:22 +00:00
jeff
b53ca6ad0a - Differentiate two UPGRADE panics so I have a better idea of what's going
on here.
2005-04-12 05:43:03 +00:00
jeff
a3d1d94c5a - Remove dead code. 2005-04-06 10:11:14 +00:00
jeff
62c728e499 - Slightly restructure acquire() so I can add more ktr information and
an assert to help find two strange bugs.
 - Remove some nearby spls.
2005-04-03 11:49:02 +00:00
jeff
27112458d3 - Add a LK_NOSHARE flag which forces all shared lock requests to be
treated as exclusive lock requests.

Sponsored by:	Isilon Systems, Inc.
2005-03-31 05:18:19 +00:00
jeff
2210f285f1 - Remove apause(). It makes no sense with our present mutex implementation
since simply unlocking a mutex does not ensure that one of the waiters
   will run and acquire it.  We're more likely to reacquire the mutex
   before anyone else has a chance.  It has also bit me three times now, as
   it's not safe to drop the interlock before sleeping in many cases.

Sponsored by:	Isilon Systems, Inc.
2005-03-31 04:25:59 +00:00
jeff
2ed686ac4d - Don't bump the count twice in the LK_DRAIN case.
Sponsored by:	Isilon Systems, Inc.
2005-03-28 12:52:10 +00:00
jeff
26329d2e37 - Restore COUNT() in all of its original glory. Don't make it dependent
on DEBUG as ufs will soon grow a dependency on this count.

Discussed with:	bde
Sponsored by:	Isilon Systems, Inc.
2005-03-25 00:00:44 +00:00
jeff
5fffa95033 - Complete the implementation of td_locks. Track the number of outstanding
lockmgr locks that this thread owns.  This is complicated due to
   LK_KERNPROC and because lockmgr tolerates unlocking an unlocked lock.

Sponsored by:	Isilon Systes, Inc.
2005-03-24 09:35:06 +00:00
jeff
833fbdb710 - transferlockers() requires the interlock to be SMP safe.
Sponsored by:	Isilon Systems, Inc.
2005-03-15 09:27:45 +00:00
jeff
b28fe2715d - Include LK_INTERLOCK in LK_EXTFLG_MASK so that it makes its way into
acquire.
 - Correct the condition that causes us to skip apause() to only require
   the presence of LK_INTERLOCK.

Sponsored by:	Isilon Systems, Inc.
2005-01-25 16:06:05 +00:00
jeff
13b2f39f55 - Do not use APAUSE if LK_INTERLOCK is set. We lose synchronization
if the lockmgr interlock is dropped after the caller's interlock
   is dropped.
 - Change some lockmgr KTRs to be slightly more helpful.

Sponsored By:	Isilon Systems, Inc.
2005-01-24 10:20:59 +00:00
imp
20280f1431 /* -> /*- for copyright notices, minor format tweaks as necessary 2005-01-06 23:35:40 +00:00
ps
93adaab3cd When upgrading the shared lock to an exclusive lock, if we discover
that the exclusive lock is already held, then we call panic. Don't
clobber internal lock state before panic'ing. This change improves
debugging if this case were to happen.

Submitted by:	Mohan Srinivasan mohans at yahoo-inc dot com
Reviewed by:	rwatson
2004-11-29 22:58:32 +00:00
kan
a060608a2d Reintroduce slightly modified patch from kern/69964. Check for
LK_HAVE_EXL in both acquire invocations.

MFC after:	5 days
2004-08-27 01:41:28 +00:00
kan
edf5a7b07f Temporarily back out r1.74 as it seems to cause a number of regressions
accordimg to numerous reports. It  might get reintroduced some time later
when an exact failure mode is understood better.
2004-08-23 02:39:45 +00:00
kan
2c6402abdd Upgrading a lock does not play well together with acquiring an exclusive lock
and can lead to two threads being granted exclusive access. Check that no one
has the same lock in exclusive  mode before proceeding to acquire it.

The LK_WANT_EXCL and LK_WANT_UPGRADE bits act as mini-locks and can block
other threads.  Normally this is not a problem since the mini locks are
upgraded to full locks and the release of the locks will unblock the other
threads.  However if a thread reset the bits without obtaining a full lock
other threads are not awoken. Add missing wakeups for these cases.

PR:		kern/69964
Submitted by:	Stephan Uphoff <ups at tree dot com>
Very good catch by: Stephan Uphoff <ups at tree dot com>
2004-08-16 15:01:22 +00:00
rwatson
3184300f78 Don't include a "\n" in KTR output, it confuses automatic parsing. 2004-07-23 20:12:56 +00:00
tjr
7a46b27935 Move TDF_DEADLKTREAT into td_pflags (and rename it accordingly) to avoid
having to acquire sched_lock when manipulating it in lockmgr(), uiomove(),
and uiomove_fromphys().

Reviewed by:	jhb
2004-06-03 01:47:37 +00:00
kan
6ecda71663 Add pid to the info printed in lockmgr_printinfo. This makes VFS
diagnostic messages slightly more useful.
2004-01-06 04:34:13 +00:00
truckman
68ed1d12ac Rearrange the SYSINIT order to call lockmgr_init() earlier so that
the runtime lockmgr initialization code in lockinit() can be eliminated.

Reviewed by:	jhb
2003-07-16 01:00:39 +00:00
truckman
f985965120 Extend the mutex pool implementation to permit the creation and use of
multiple mutex pools with different options and sizes.  Mutex pools can
be created with either the default sleep mutexes or with spin mutexes.
A dynamically created mutex pool can now be destroyed if it is no longer
needed.

Create two pools by default, one that matches the existing pool that
uses the MTX_NOWITNESS option that should be used for building higher
level locks, and a new pool with witness checking enabled.

Modify the users of the existing mutex pool to use the appropriate pool
in the new implementation.

Reviewed by:	jhb
2003-07-13 01:22:21 +00:00
obrien
3b8fff9e4c Use __FBSDID(). 2003-06-11 00:56:59 +00:00
jhb
a8c7b4178e 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
jhb
e4bcd25517 Replace calls to WITNESS_SLEEP() and witness_list() with equivalent calls
to WITNESS_WARN().
2003-03-04 21:03:05 +00:00
jeff
9e4c9a6ce9 - 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
bdd1053074 - Add a WITNESS_SLEEP() for the appropriate cases in lockmgr(). 2003-02-16 10:39:49 +00:00
julian
cae0aa62ce 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
e8efa7328e 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
davidxu
4b9b549ca2 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