done in consumers code: using locks properties is much more appropriate.
Fix current code doing these bogus checks.
Note: Really, callout are not usable by all !(LC_SPINLOCK | LC_SLEEPABLE)
primitives like rmlocks doesn't implement the generic lock layer
functions, but they can be equipped for this, so the check is still
valid.
Tested by: matteo, kris (earlier version)
Reviewed by: jhb
- Expose sbrelease_internal(), a variant of sbrelease() with no
expectations about the validity of locks in the socket buffer.
- Use sbrelease_internel() in sorflush(), and as a result avoid intializing
and destroying a socket buffer lock for the temporary stack copy of the
actual buffer, asb.
- Add a comment indicating why we do what we do, and remove an XXX since
things have gotten less ugly in sorflush() lately.
This makes socket close cleaner, and possibly also marginally faster.
MFC after: 3 weeks
referencing the files VM pages are returned from the network stack,
making changes to the file safe.
This flag does not guarantee that the data has been transmitted to the
other end.
free function controlable, instead of passing the KVA of the buffer
storage as the first argument.
Fix all conventional users of the API to pass the KVA of the buffer
as the first argument, to make this a no-op commit.
Likely break the only non-convetional user of the API, after informing
the relevant committer.
Update the mbuf(9) manual page, which was already out of sync on
this point.
Bump __FreeBSD_version to 800016 as there is no way to tell how
many arguments a CPP macro needs any other way.
This paves the way for giving sendfile(9) a way to wait for the
passed storage to have been accessed before returning.
This does not affect the memory layout or size of mbufs.
Parental oversight by: sam and rwatson.
No MFC is anticipated.
read socket buffers in shutdown() and close():
- Call socantrcvmore() before sblock() to dislodge any threads that
might be sleeping (potentially indefinitely) while holding sblock(),
such as a thread blocked in recv().
- Flag the sblock() call as non-interruptible so that a signal
delivered to the thread calling sorflush() doesn't cause sblock() to
fail. The sblock() is required to ensure that all other socket
consumer threads have, in fact, left, and do not enter, the socket
buffer until we're done flushin it.
To implement the latter, change the 'flags' argument to sblock() to
accept two flags, SBL_WAIT and SBL_NOINTR, rather than one M_WAITOK
flag. When SBL_NOINTR is set, it forces a non-interruptible sx
acquisition, regardless of the setting of the disposition of SB_NOINTR
on the socket buffer; without this change it would be possible for
another thread to clear SB_NOINTR between when the socket buffer mutex
is released and sblock() is invoked.
Reviewed by: bz, kmacy
Reported by: Jos Backus <jos at catnook dot com>
resulted in the argument to the make_dev() to be a unit number.
Correct this by supplying a minor number to make_dev(), and using
the unit number for the calculation of the slave tty name.
Reported and tested by: Peter Holm
Reviewed by: jhb
Yet another pointy hat to: kib
MFC after: 1 day
while the thread does not hold the thread lock would stop blocking for
subsequent interruptible sleeps and would always immediately fail the
sleep with EWOULDBLOCK instead (even sleeps that didn't have a timeout).
Some background:
- KSE has a facility for allowing one thread to interrupt another thread.
During this process, the target thread aborts any interruptible sleeps
much as if the target thread had a pending signal. Once the target
thread acknowledges the interrupt, normal sleep handling resumes. KSE
manages this via the TDF_INTERRUPTED flag. Specifically, it sets the
flag when it sends an interrupt to another thread and clears it when
the interrupt is acknowledged. (Note that this is purely a software
interrupt sort of thing and has no relation to hardware interrupts
or kernel interrupt threads.)
- The old code for handling the sleep timeout race handled the race
by setting the TDF_INTERRUPT flag and faking a KSE-style thread
interrupt to the thread in the process of going to sleep. It probably
should have just checked the TDF_TIMEOUT flag in sleepq_catch_signals()
instead.
- The bug was that the sleepq code would set TDF_INTERRUPT but it was
never cleared. The sleepq code couldn't safely clear it in case there
actually was a real KSE thread interrupt pending for the target thread
(in fact, the sleepq timeout actually stomped on said pending interrupt).
Thus, any future interruptible sleeps (*sleep(.. PCATCH ..) or
cv_*wait_sig()) would see the TDF_INTERRUPT flag set and immediately
fail with EWOULDBLOCK. The flag could be cleared if the thread belonged
to a KSE process and another thread posted an interrupt to the original
thread. However, in the more common case of a non-KSE process, the
thread would pretty much stop sleeping.
- Fix the bug by just setting TDF_TIMEOUT in the sleepq timeout code and
not messing with TDF_INTERRUPT and td_intrval. With yesterday's fix to
fix sleepq_switch() to check TDF_TIMEOUT, this is now sufficient.
MFC after: 3 days
being properly cancelled by a timeout. In general there is a race
between a the sleepq timeout handler firing while the thread is still
in the process of going to sleep. In 6.x with sched_lock, the race was
largely protected by sched_lock. The only place it was "exposed" and had
to be handled was while checking for any pending signals in
sleepq_catch_signals().
With the thread lock changes, the thread lock is dropped in between
sleepq_add() and sleepq_*wait*() opening up a new window for this race.
Thus, if the timeout fired while the sleeping thread was in between
sleepq_add() and sleepq_*wait*(), the thread would be marked as timed
out, but the thread would not be dequeued and sleepq_switch() would
still block the thread until it was awakened via some other means. In
the case of pause(9) where there is no other wakeup, the thread would
never be awakened.
Fix this by teaching sleepq_switch() to check if the thread has had its
sleep canceled before blocking by checking the TDF_TIMEOUT flag and
aborting the sleep and dequeueing the thread if it is set.
MFC after: 3 days
Reported by: dwhite, peter
`kn_sdata' member of the newly registered knote. The problem is that
this member is overwritten by a call to kevent(2) with the EV_ADD flag,
targetted at the same kevent/knote. For instance, a userland application
may set the pointer to NULL, leading to a panic.
A testcase was provided by the submitter.
PR: kern/118911
Submitted by: MOROHOSHI Akihiko <moro@remus.dti.ne.jp>
MFC after: 1 day
- Remove the "thread" argument from the lockmgr() function as it is
always curthread now
- Axe lockcount() function as it is no longer used
- Axe LOCKMGR_ASSERT() as it is bogus really and no currently used.
Hopefully this will be soonly replaced by something suitable for it.
- Remove the prototype for dumplockinfo() as the function is no longer
present
Addictionally:
- Introduce a KASSERT() in lockstatus() in order to let it accept only
curthread or NULL as they should only be passed
- Do a little bit of style(9) cleanup on lockmgr.h
KPI results heavilly broken by this change, so manpages and
FreeBSD_version will be modified accordingly by further commits.
Tested by: matteo
Introduce a new privilege allowing to set certain IP header options
(hop-by-hop, routing headers).
Leave a few comments to be addressed later.
Reviewed by: rwatson (older version, before addressing his comments)
a run-queue. If the priority is numerically raised only change lowpri
if we're certain it will be correct. Some slop is allowed however
previously we could erroneously raise lowpri for an idle cpu that a
thread had recently run on which lead to errors in load balancing
decisions.
lockmgr lkp, when held in exclusive mode, is recursed
- Introduce the function BUF_RECURSED() which does the same for bufobj
locks based on the top of lockmgr_recursed()
- Introduce the function BUF_ISLOCKED() which works like the counterpart
VOP_ISLOCKED(9), showing the state of lockmgr linked with the bufobj
BUF_RECURSED() and BUF_ISLOCKED() entirely replace the usage of bogus
BUF_REFCNT() in a more explicative and SMP-compliant way.
This allows us to axe out BUF_REFCNT() and leaving the function
lockcount() totally unused in our stock kernel. Further commits will
axe lockcount() as well as part of lockmgr() cleanup.
KPI results, obviously, broken so further commits will update manpages
and freebsd version.
Tested by: kris (on UFS and NFS)
unp_connect(): it is expected to return with the lock held, and two
possible error paths otherwise returned with it unlocked.
The fix committed here is slightly different from the patch in the
PR, but along an alternative line suggested in the PR.
PR: 119778
MFC after: 3 days
Submitted by: James Juran <james dot juran at baesystems dot com>
was missed. As result, pty_create_slave() may index out of the names[]
bounds, creating wrong slave tty names.
Tested by: kensmith
Reviewed by: jhb
MFC after: 3 days
other. The first one survives, the rest are removed. So far, it appears
only some acpi_perf(4) BIOS tables have these invalid states, but address
this in the core to be sure to handle other potential driver data.
PR: kern/114722
Tested by: stefan.lambrev / moneybookers.com
MFC after: 3 days
lowest priority on the queue for the current cpu vs curthread's
priority. In the case that curthread is waking up many threads of a
lower priority as would happen with a turnstile_broadcast() or wakeup()
of many threads this prevents them from all ending up on the current cpu.
- In sched_add() make the relationship between a scheduled ithread and
the current cpu advisory rather than strict. Only give the ithread
affinity for the current cpu if it's actually being scheduled from
a hardware interrupt. This prevents it from migrating when it simply
blocks on a lock.
Sponsored by: Nokia
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.
KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.
Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
panic but it won't actually lock anything.
This can lead some paths to reach lockmgr_disown() with inconsistent
lock which will let trigger the relative assertions.
Fix those in order to recognize panic situation and to not trigger.
Reported by: pho
Submitted by: kib
maintain a separate td_incruntime to hold unbilled CPU usage for
the thread that has the previous properties of td_runtime.
When thread information is requested using the thread monitoring
sysctls, export thread td_runtime instead of process rusage runtime
in kinfo_proc.
This restores the display of individual ithread and other kernel
thread CPU usage since inception in ps -H and top -SH, as well for
libthr user threads, valuable debugging information lost with the
move to try kthreads since they are no longer independent processes.
There is universal agreement that we should rewrite the process and
thread export sysctls, but this commit gets things going a bit
better in the mean time. Likewise, there are resevations about the
continued validity of statclock given the speed of modern processors.
Reviewed by: attilio, emaste, jhb, julian
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.
Manpage and FreeBSD_version will be updated through further commits.
As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.
Tested by: Diego Sardina <siarodx at gmail dot com>,
Andrea Di Pasquale <whyx dot it at gmail dot com>
Now, lockmgr() function can only be called passing curthread and the
KASSERT() is upgraded according with this.
In order to support on-the-fly owner switching, the new function
lockmgr_disown() has been introduced and gets used in BUF_KERNPROC().
KPI, so, results changed and FreeBSD version will be bumped soon.
Differently from previous code, we assume idle thread cannot try to
acquire the lockmgr as it cannot sleep, so loose the relative check[1]
in BUF_KERNPROC().
Tested by: kris
[1] kib asked for a KASSERT in the lockmgr_disown() about this
condition, but after thinking at it, as this is a well known general
rule, I found it not really necessary.
implement shm_open(2) and shm_unlink(2) in the kernel:
- Each shared memory file descriptor is associated with a swap-backed vm
object which provides the backing store. Each descriptor starts off with
a size of zero, but the size can be altered via ftruncate(2). The shared
memory file descriptors also support fstat(2). read(2), write(2),
ioctl(2), select(2), poll(2), and kevent(2) are not supported on shared
memory file descriptors.
- shm_open(2) and shm_unlink(2) are now implemented as system calls that
manage shared memory file descriptors. The virtual namespace that maps
pathnames to shared memory file descriptors is implemented as a hash
table where the hash key is generated via the 32-bit Fowler/Noll/Vo hash
of the pathname.
- As an extension, the constant 'SHM_ANON' may be specified in place of the
path argument to shm_open(2). In this case, an unnamed shared memory
file descriptor will be created similar to the IPC_PRIVATE key for
shmget(2). Note that the shared memory object can still be shared among
processes by sharing the file descriptor via fork(2) or sendmsg(2), but
it is unnamed. This effectively serves to implement the getmemfd() idea
bandied about the lists several times over the years.
- The backing store for shared memory file descriptors are garbage
collected when they are not referenced by any open file descriptors or
the shm_open(2) virtual namespace.
Submitted by: dillon, peter (previous versions)
Submitted by: rwatson (I based this on his version)
Reviewed by: alc (suggested converting getmemfd() to shm_open())
dev2udev() when a tty was being detached concurrently with the sysctl
handler:
- Hold the 'tty_list_mutex' lock while we read all the fields out of the
struct tty for copying out later. Previously the pty(4) and pts(4)
destroy routines could set t_dev to NULL, drop their reference on the
tty and destroy the cdev while the sysctl handler was attempting to
invoke dev2udev() on the cdev being destroyed. This happened when the
sysctl handler read the value of t_dev prior to it being set to NULL
either due to it being stale or due to timing races. By holding the
list lock we guarantee that the destroy routines will block in ttyrel()
in that case and not destroy the cdev until after we've copied all of our
data. We may see a NULL cdev pointer or we may see the previous value,
but the previous value will no longer point to a destroyed cdev if we
see it.
- Fix the ttyfree() routine used by tty device drivers in their detach
methods to use ttyrel() on the tty so we don't leak them. Also, fix it
to use the same order of operations as pty/pts destruction (set t_dev
NULL, ttyrel(), destroy_dev()) so it cooperates with the sysctl handler.
MFC after: 3 days
Tested by: avatar
This makes it possible to support ftruncate() on non-vnode file types in
the future.
- 'struct fileops' grows a 'fo_truncate' method to handle an ftruncate() on
a given file descriptor.
- ftruncate() moves to kern/sys_generic.c and now just fetches a file
object and invokes fo_truncate().
- The vnode-specific portions of ftruncate() move to vn_truncate() in
vfs_vnops.c which implements fo_truncate() for vnode file types.
- Non-vnode file types return EINVAL in their fo_truncate() method.
Submitted by: rwatson
- spell 16384 as 16384 and not as BKVASIZE. 16384 is (not quite) just a
magic size that works well in practice. BKVASIZE should be MAXBSIZE
(65536), but is 16384 because i386's don't have enough kva for it to
be MAXBSIZE; 16384 works (not so well) for it for much the same reasons
that it works well in the heuristic.
- expand and/or add comments about this and other details.
- don't explicitly inline this function.
- fix some other style bugs.
ABI override binary isn't found. This could probably be smoother, but
it is what I did in p4 change #126891 on 2007/09/27. It should solve
the "ld-elf32.so.1"-in-chroot problem.
happen if there are no files open. Accounting for these can
eventually return a negative value for olenp causing sysctl to
crash with a bad malloc.
Reported by: Pawel Worach <pawel.worach@gmail.com>
- Clear all of the gc flags before doing a run. Stale flags were causing
us to skip some descriptors.
- If a unp socket has been marked REF in a gc pass it can't be dead.
Found by: rwatson's test tool.
- Introduce a finit() which is used to initailize the fields of struct file
in such a way that the ops vector is only valid after the data, type,
and flags are valid.
- Protect f_flag and f_count with atomic operations.
- Remove the global list of all files and associated accounting.
- Rewrite the unp garbage collection such that it no longer requires
the global list of all files and instead uses a list of all unp sockets.
- Mark sockets in the accept queue so we don't incorrectly gc them.
Tested by: kris, pho
machine-independent support for superpages. (The earlier part was
the rewrite of the physical memory allocator.) The remainder of the
code required for superpages support is machine-dependent and will
be added to the various pmap implementations at a later date.
Initially, I am only supporting one large page size per architecture.
Moreover, I am only enabling the reservation system on amd64. (In
an emergency, it can be disabled by setting VM_NRESERVLEVELS to 0
in amd64/include/vmparam.h or your kernel configuration file.)
so that the results end up in the DDB output stream rather than the
console output stream.
This should likely also be done for the vprint() function it calls.
MFC after: 3 months
This option just adds complexity and the new implementation no longer
will support it, so axing it now that it is unused is probabilly the
better idea.
FreeBSD version is bumped in order to reflect the KPI breakage introduced
by this patch.
In the ports tree, kris found that only old OSKit code uses it, but as
it is thought to work only on 2.x kernels serie, version bumping will
solve any problem.
with the interlock), owner of the lock should be only curthread or at
least, for its limited usage, NULL which identifies LK_KERNPROC.
The thread "extra argument" for the lockmgr interface is going to be
removed in the near future, but for the moment, just let kernel run for
some days with this check on in order to find potential deadlocking
places around the kernel and fix them.
p_candebug() will return EAGAIN which, if the other process never
leaves execve(), will result in the sysctl spinning and never returning
to userspace. Processes should always eventually leave execve(), but
spinning in kernel while we wait is bad for countless reasons, and
particularly harmful if execve() itself is deadlocked.
Possibly we should return another error, or return a marker indicating
the thread is in execve() so it can be reported that way in userspace.
Reported by: kris
equivalent with this and so operate the switch.
That call is the only one remaining LK_EXCLUPGRADE consumer and removing
it will prepare the ground for LK_EXCLUPGRADE axing and further
lockmgr improvements.
Discussed with: jeff, ups
mounted FS' problems. These are more along the lines of 'avoiding an
avoidable panic' than a complete solution to removable devices. We
now close the barn door after the horse has gotten lose and has been
hit by a truck, as it were. The barn no longer catches fire in this
case, but the horse is still dead :-).
The vfs_bio.c fix causes us not to put a failed write back into the
dirty pool if the error returned was ENXIO. In that case, the buffer
is treated like any other clean buffer that's being retured. ENXIO
means the device isn't there anymore and will never be there again in
the future, so retrying is futile.
The vfs_mount.c fix treats 'ENXIO' as success for unmounting a file
system. If the device is gone, retrying later won't help and we'll
never be able to unmount the device.
These two are part of a larger patch set submitted by the author. The
other patches will be forth coming. I added comments to these two
patches.
Submitted by: Henrik Gulbrandsen
Reviewed by: phk@
PR: usb/46176 (partial)
dump using mechanically generated/extracted debugging output rather than
a simple memory dump. Current sources of debugging output are:
- DDB output capture buffer, if there is captured output to save
- Kernel message buffer
- Kernel configuration, if included in kernel
- Kernel version string
- Panic message
Textdumps are stored in swap/dump partitions as with regular dumps, but
are laid out as ustar files in order to allow multiple parts to be stored
as a stream of sequentially written blocks. Blocks are written out in
reverse order, as the size of a textdump isn't known a priori. As with
regular dumps, they will be extracted using savecore(8).
One new DDB(4) command is added, "textdump", which accepts "set",
"unset", and "status" arguments. By default, normal kernel dumps are
generated unless "textdump set" is run in order to schedule a textdump.
It can be canceled using "textdump unset" to restore generation of a
normal kernel dump.
Several sysctls exist to configure aspects of textdumps;
debug.ddb.textdump.pending can be set to check whether a textdump is
pending, or set/unset in order to control whether the next kernel dump
will be a textdump from userspace.
While textdumps don't have to be generated as a result of a DDB script
run automatically as part of a kernel panic, this is a particular useful
way to use them, as instead of generating a complete memory dump, a
simple transcript of an automated DDB session can be captured using the
DDB output capture and textdump facilities. This can be used to
generate quite brief kernel bug reports rich in debugging information
but not dependent on kernel symbol tables or precisely synchronized
source code. Most textdumps I generate are less than 100k including
the full message buffer. Using textdumps with an interactive debugging
session is also useful, with capture being enabled/disabled in order to
record some but not all of the DDB session.
MFC after: 3 months
kern.console format as is. Thus, no difference in output format should
appear after this commit.
Reviewed by: cognet@ (mentor)
Approved by: cognet@ (mentor)
for that argument. This will allow DDB to detect the broad category of
reason why the debugger has been entered, which it can use for the
purposes of deciding which DDB script to run.
Assign approximate why values to all current consumers of the
kdb_enter() interface.
details from consumers.
- Track individual selecters on a per-descriptor basis such that there
are no longer collisions and after sleeping for events only those
descriptors which triggered events must be rescaned.
- Protect the selinfo (per descriptor) structure with a mtx pool mutex.
mtx pool mutexes were chosen to preserve api compatibility with
existing code which does nothing but bzero() to setup selinfo
structures.
- Use a per-thread wait channel rather than a global wait channel.
- Hide select implementation details in a seltd structure which is
opaque to the rest of the kernel.
- Provide a 'selsocket' interface for those kernel consumers who wish to
select on a socket when they have no fd so they no longer have to
be aware of select implementation details.
Tested by: kris
Reviewed on: arch
the ABI when enabled. There is no longer an embedded lock_profile_object
in each lock. Instead a list of lock_profile_objects is kept per-thread
for each lock it may own. The cnt_hold statistic is now always 0 to
facilitate this.
- Support shared locking by tracking individual lock instances and
statistics in the per-thread per-instance lock_profile_object.
- Make the lock profiling hash table a per-cpu singly linked list with a
per-cpu static lock_prof allocator. This removes the need for an array
of spinlocks and reduces cache contention between cores.
- Use a seperate hash for spinlocks and other locks so that only a
critical_enter() is required and not a spinlock_enter() to modify the
per-cpu tables.
- Count time spent spinning in the lock statistics.
- Remove the LOCK_PROFILE_SHARED option as it is always supported now.
- Specifically drop and release the scheduler locks in both schedulers
since we track owners now.
In collaboration with: Kip Macy
Sponsored by: Nokia
on 1/2 of each of the successive limits tied to the limit for
2k clusters.
- Adds real functionality in so that doing a sysctl to change these
actually changes them :-)
MFC after: 1 week
when applicable.
Aquire Giant slightly later for vnlru.
In the syncer, aquire the Giant only when a vnode belongs to the
non-MPsafe fs.
In both speedup_syncer() and syncer_shutdown(), remove the syncer thread from
the lbolt sleep queue after the syncer state is modified, not before.
Herded by: attilio
Tested by: Peter Holm
Reviewed by: ups
MFC after: 1 week
This makes updates mounts such as:
"mount -u -o rdonly" work more like, "mount -u -o ro".
References to "-o rdonly" were changed to "-o ro" in revision 1.60 of
the mount(8) man page,
but some people still like to use "-o rdonly" since it was documented
in earlier versions of FreeBSD.
Requested by: rwatson
MFC after: 1 week
within the jail are never freed. si_cred is only used by the MAC framework so
make the cred reference conditional on it being compiled in, this is not a fix
and will need to be reviewed for any new consumers of si_cred.
This will quell some user complaint when using jails with a default kernel.
Reviewed by: rwatson
MFC after: 3 days
dereferencing. Unaligned access could cause panic on strict alignment
architectures.
Reviewed by: marcel, marius (also tested on sparc64, thanks !)
MFC after: 3 days
support its -k argument:
kern.proc.kstack - dump the kernel stack of a process, if debugging
is permitted.
This sysctl is present if either "options DDB" or "options STACK" is
compiled into the kernel. Having support for tracing the kernel
stacks of processes from user space makes it much easier to debug
(or understand) specific wmesg's while avoiding the need to enter
DDB in order to determine the path by which a process came to be
blocked on a particular wait channel or lock.
- Introduce per-architecture stack_machdep.c to hold stack_save(9).
- Introduce per-architecture machine/stack.h to capture any common
definitions required between db_trace.c and stack_machdep.c.
- Add new kernel option "options STACK"; we will build in stack(9) if it is
defined, or also if "options DDB" is defined to provide compatibility
with existing users of stack(9).
Add new stack_save_td(9) function, which allows the capture of a stacktrace
of another thread rather than the current thread, which the existing
stack_save(9) was limited to. It requires that the thread be neither
swapped out nor running, which is the responsibility of the consumer to
enforce.
Update stack(9) man page.
Build tested: amd64, arm, i386, ia64, powerpc, sparc64, sun4v
Runtime tested: amd64 (rwatson), arm (cognet), i386 (rwatson)
its -f and -v arguments:
kern.proc.filedesc - dump file descriptor information for a process, if
debugging is permitted, including socket addresses, open flags, file
offsets, file paths, etc.
kern.proc.vmmap - dump virtual memory mapping information for a process,
if debugging is permitted, including layout and information on
underlying objects, such as the type of object and path.
These provide a superset of the information historically available
through the now-deprecated procfs(4), and are intended to be exported
in an ABI-robust form.
linker interfaces for looking up function names and offsets from
instruction pointers. Create two variants of each call: one that is
"DDB-safe" and avoids locking in the linker, and one that is safe for
use in live kernels, by virtue of observing locking, and in particular
safe when kernel modules are being loaded and unloaded simultaneous to
their use. This will allow them to be used outside of debugging
contexts.
Modify two of three current stack(9) consumers to use the DDB-safe
interfaces, as they run in low-level debugging contexts, such as inside
lockmgr(9) and the kernel memory allocator.
Update man page.
information in support of DDB(4); these functions bypass normal linker
locking as they may run in contexts where locking is unsafe (such as the
kernel debugger).
Add a new interface linker_ddb_search_symbol_name(), which looks up a
symbol name and offset given an address, and also
linker_search_symbol_name() which does the same but *does* follow the
locking conventions of the linker.
Unlike existing functions, these functions place the name in a
caller-provided buffer, which is stable even after linker locks have been
released. These functions will be used in upcoming revisions to stack(9)
to support kernel stack trace generation in contexts as part of a live,
rather than suspended, kernel.
per-cpu area. cp_time[] goes away and a new function creates a merged
cp_time-like array for things like linprocfs, sysctl etc. The
atomic ops for updating cp_time[] in statclock go away, and the scope
of the thread lock is reduced.
sysctl kern.cp_time returns a backwards compatible cp_time[] array.
A new kern.cp_times sysctl returns the individual per-cpu stats.
I have pending changes to make top and vmstat optionally show per-cpu
stats.
I'm very aware that there are something like 5 or 6 other versions "out
there" for doing this - but none were handy when I needed them.
I did merge my changes with John Baldwin's, and ended up replacing a
few chunks of my stuff with his, and stealing some other code.
Reviewed by: jhb
Partly obtained from: jhb
Currently, Giant is not too much contented so that it is ok to treact it
like any other mutexes.
Please don't forget to update your own custom config kernel files.
Approved by: cognet, marcel (maintainers of arches where option is
not enabled at the moment)
currently, before to spin the turnstile spinlock is acquired and the
waiters flag is set.
This is not strictly necessary, so just spin before to acquire the
spinlock and to set the flags.
This will simplify a lot other functions too, as now we have the waiters
flag set only if there are actually waiters.
This should make wakeup/sleeping couplet faster under intensive mutex
workload.
This also fixes a bug in rw_try_upgrade() in the adaptive case, where
turnstile_lookup() will recurse on the ts_lock lock that will never be
really released [1].
[1] Reported by: jeff with Nokia help
Tested by: pho, kris (earlier, bugged version of rwlock part)
Discussed with: jhb [2], jeff
MFC after: 1 week
[2] John had a similar patch about 6.x and/or 7.x about mutexes probabilly
should never be moved by one lock to another.
As, luckily, nothing in our tree is using it, axe the function.
This breaks lockmgr KPI, so interested, third-party modules should update
their source code with appropriate replacement.
Ok'ed by: ups, rwatson
MFC after: 3 days
while the global callout spinlock is not held, and can lead to PF#.
Reported by: dougb, Mark Atkinson <atkin901 at yahoo dot com>
Tested by: dougb
Diagnosed by: jhb
rwlocks in conjuction with callouts. The function does basically what
callout_init_mtx() alredy does with the difference of using a rwlock
as extra argument.
CALLOUT_SHAREDLOCK flag can be used, now, in order to acquire the lock only
in read mode when running the callout handler. It has no effects when used
in conjuction with mtx.
In order to implement this, underlying callout functions have been made
completely lock type-unaware, so accordingly with this, sysctl
debug.to_avg_mtxcalls is now changed in the generic
debug.to_avg_lockcalls.
Note: currently the allowed lock classes are mutexes and rwlocks because
callout handlers run in softclock swi, so they cannot sleep and they
cannot acquire sleepable locks like sx or lockmgr.
Requested by: kmacy, pjd, rwatson
Reviewed by: jhb
o buffered write, for chunks smaller than PIPE_MINDIRECT bytes
o direct write, for everything else
A call to writev(2) may receive struct iov of various size and the
kernel may have to switch from one solution to the other. Before doing
this, it must wake reader processes and any select/poll/kqueue up.
This commit fixes a bug where select/poll/kqueue are not triggered
when switching from buffered write to direct write. It adds calls to
pipeselwakeup().
I give more details on freebsd-arch@:
http://lists.freebsd.org/pipermail/freebsd-arch/2007-September/006790.html
This should fix issues with Erlang (lang/erlang) and kqueue.
Reported by: Rickard Green (Erlang)
an unified way for all the lock primitives to express lock assertions.
Currenty, lockmgrs and rmlocks don't have assertions, so just panic in
that case.
This will be a base for more callout improvements.
Ok'ed by: jhb, jeff
process_fini, thread_ctor, thread_dtor, thread_init, thread_fini. This
will allow us to extend dynamically areas in proc/thread for dtrace ;-)
Reviewed by: rwatson
- process_ctor,dtor, init and fini
- thread_ctor,dtor, init and fini
This allows the ability to add on additional things
during construction/destruction of threads and processes.
Reviewed by: rwatson
communicate that it relates to (is called by) thread_alloc()
o Add cpu_thread_free() which is called from thread_free()
to counter-act cpu_thread_alloc().
i386: Have cpu_thread_free() call cpu_thread_clean() to
preserve behaviour.
ia64: Have cpu_thread_free() call mtx_destroy() for the
mutex initialized in cpu_thread_alloc().
PR: ia64/118024
opposed to what process. Since threads by default have teh name of the
process unless over-written with more useful information, just print the
thread name instead.
proc_rwmen.
Otherwise copy on write may create an anonymous page that is
not marked as dirty. Since writing data to these pages
in this function also does not dirty these pages they may be
later discarded by the pagedaemon.
- Use unit2minor() and minor2unit() to generate minor numbers to support
unit numbers higher than 255.
- Use simple string operations on the 'names' array rather than hard-coded
constants and switch statements so that more ptys can be added by simply
expanding the 'names' array.
MFC after: 1 week
lock optimized for almost exclusive reader access. (see also rmlock.9)
TODO:
Convert to per cpu variables linkerset as soon as it is available.
Optimize UP (single processor) case.
silent NULL pointer dereference in the i386 and sparc64 pmap_pinit()
when the kmem_alloc_nofault() failed to allocate address space. Both
functions now return error instead of panicing or dereferencing NULL.
As consequence, vmspace_exec() and vmspace_unshare() returns the errno
int. struct vmspace arg was added to vm_forkproc() to avoid dealing
with failed allocation when most of the fork1() job is already done.
The kernel stack for the thread is now set up in the thread_alloc(),
that itself may return NULL. Also, allocation of the first process
thread is performed in the fork1() to properly deal with stack
allocation failure. proc_linkup() is separated into proc_linkup()
called from fork1(), and proc_linkup0(), that is used to set up the
kernel process (was known as swapper).
In collaboration with: Peter Holm
Reviewed by: jhb
Put in a little comment explaining why it went away.
Re-enable it in the case there an exisiting process is just splitting
off its address space and file descriptors.
(I donpt think anything uses that code but it needs some sort of locking
and this does the job.
Reviewed by: Davidxu, alc, others
MFC after: 3 days
to change the freq before the other CPUs are active. The current code
always attempts to change all CPUs to match each other, and the requisite
sched_bind() call won't work before APs are launched.
userland preemption directly from hardclock() via sched_clock() when a
thread uses up a full quantum instead of using a periodic timeout to cause
a userland preemption every so often. This fixes a potential deadlock
when IPI_PREEMPTION isn't enabled where softclock blocks on a lock held
by a thread pinned or bound to another CPU. The current thread on that
CPU will never be preempted while softclock is blocked.
Note that ULE already drives its round-robin userland preemption from
sched_clock() as well and always enables IPI_PREEMPT.
MFC after: 1 week
out instead of returning an error.
(1) This makes the behavior consistent with mount(2).
(2) This makes update mounts on the root file system work properly.
(3) The explicit checks for MNT_ROOTFS in src/sbin/fsck_ffs/main.c
and src/usr.sbin/mountd/mountd.c which were put in to
eliminate errors during update mounts on the root file system
can be removed.
The only place were MNT_ROOTFS can be validly set
is inside the kernel, i.e. with vfs_mountroot_try().
Reviewed by: phk
MFC after: 3 days
kthread_add() takes the same parameters as the old kthread_create()
plus a pointer to a process structure, and adds a kernel thread
to that process.
kproc_kthread_add() takes the parameters for kthread_add,
plus a process name and a pointer to a pointer to a process instead of just
a pointer, and if the proc * is NULL, it creates the process to the
specifications required, before adding the thread to it.
All other old kthread_xxx() calls return, but act on (struct thread *)
instead of (struct proc *). One reason to change the name is so that
any old kernel modules that are lying around and expect kthread_create()
to make a process will not just accidentally link.
fix top to show kernel threads by their thread name in -SH mode
add a tdnam formatting option to ps to show thread names.
make all idle threads actual kthreads and put them into their own idled process.
make all interrupt threads kthreads and put them in an interd process
(mainly for aesthetic and accounting reasons)
rename proc 0 to be 'kernel' and it's swapper thread is now 'swapper'
man page fixes to follow.
This change introduces audit_proc_coredump() which is called by coredump(9)
to create an audit record for the coredump event. When a process
dumps a core, it could be security relevant. It could be an indicator that
a stack within the process has been overflowed with an incorrectly constructed
malicious payload or a number of other events.
The record that is generated looks like this:
header,111,10,process dumped core,0,Thu Oct 25 19:36:29 2007, + 179 msec
argument,0,0xb,signal
path,/usr/home/csjp/test.core
subject,csjp,csjp,staff,csjp,staff,1101,1095,50457,10.37.129.2
return,success,1
trailer,111
- We allocate a completely new record to make sure we arent clobbering
the audit data associated with the syscall that produced the core
(assuming the core is being generated in response to SIGABRT and not
an invalid memory access).
- Shuffle around expand_name() so we can use the coredump name at the very
beginning of the coredump call. Make sure we free the storage referenced
by "name" if we need to bail out early.
- Audit both successful and failed coredump creation efforts
Obtained from: TrustedBSD Project
Reviewed by: rwatson
MFC after: 1 month
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:
mac_<object>_<method/action>
mac_<object>_check_<method/action>
The previous naming scheme was inconsistent and mostly
reversed from the new scheme. Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier. Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods. Also simplify, slightly,
some entry point names.
All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.
Sponsored by: SPARTA (original patches against Mac OS X)
Obtained from: TrustedBSD Project, Apple Computer
audit it at the beginning of the syscall. This fixes a problem
where the user supplies an invalid process ID which is > 0 which
results in the PID argument not being audited.
Obtained from: TrustedBSD Project
MFC after: 1 week
After discussions with jeff, alc, (various Ironport people), david Xu,
and mostly Alfred (who found the problem) it has been demonstrated that this
is not needed for our implementations of threads and represents a real
(as in we've seen it happen a lot) deadlock danger.
Several points:
Since forking multiple threads is not allowed, and posix states that
any mutexes owned by othre threads wilol be owned in the child by
phantom threads, and therads shouldn't ba accessing shared structures without
protection, It can be proved that if this leads to the child process accessing
inconsistent data, it's a programming error.
The mode of thread_single() being used in fork() is the wrong one.
It is using SINGLE_NO_EXIT when it should be using SINGLE_BOUNDARY.
Even if this we used, System processes have no need to do it as they have
no userland to get inconsistent.
This commmit first fixes the above bugs to get tehm correct in CVS.
then removes them with #ifdef.
This is so that history contains the corrected version should it
be needed in the future.
This code may be needed if we implement the forkall() syscall from
Solaris. It may be needed for other non-posix thread libraries
at some time in the future, so let the code sit for a short while
while I do some work on it anyhow.
This removes a reproducible lockup in NFS.
It may be argued that maybe doing a fork while holding a vnode lock may
not be the best idea in th efirst place but it shouldn't cause a deadlock.
The removal has been running under soak test for several days now.
This removal should be seriously considered for 7.0 and RELENG_6.
Note. There is code in the core-dumping code that may have a similar problem
with coredumping threaded processes
MFC After: 4 days
kern/sched_ule.c - Add __powerpc__ to the list of supported architectures
powerpc/conf/GENERIC - Swap SCHED_4BSD with SCHED_ULE
powerpc/powerpc/genassym.c - Export TD_LOCK field of thread struct
powerpc/powerpc/swtch.S - Handle new 3rd parameter to cpu_switch() by
updating the old thread's lock. Note: uniprocessor-only, will require
modification for MP support.
powerpc/powerpc/vm_machdep.c - Set 3rd param of cpu_switch to mutex of
old thread's lock, making the call a no-op.
Reviewed by: marcel, jeffr (slightly older version)
for kldstat(2).
This allows libdtrace to determine the exact file from which
a kernel module was loaded without having to guess.
The kldstat(2) API is versioned with the size of the
kld_file_stat structure, so this change creates version 2.
Add the pathname to the verbose output of kldstat(8) too.
MFC: 3 days
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.
I'd LOVE to do this rename in 7.0 so that we can eventually MFC the
new kthread_xxx() calls.
This commit includes the following core components:
* sample configuration file for sensorsd
* rc(8) script and glue code for sensorsd(8)
* sysctl(3) doc fixes for CTL_HW tree
* sysctl(3) documentation for hardware sensors
* sysctl(8) documentation for hardware sensors
* support for the sensor structure for sysctl(8)
* rc.conf(5) documentation for starting sensorsd(8)
* sensor_attach(9) et al documentation
* /sys/kern/kern_sensors.c
o sensor_attach(9) API for drivers to register ksensors
o sensor_task_register(9) API for the update task
o sysctl(3) glue code
o hw.sensors shadow tree for sysctl(8) internal magic
* <sys/sensors.h>
* HW_SENSORS definition for <sys/sysctl.h>
* sensors display for systat(1), including documentation
* sensorsd(8) and all applicable documentation
The userland part of the framework is entirely source-code
compatible with OpenBSD 4.1, 4.2 and -current as of today.
All sensor readings can be viewed with `sysctl hw.sensors`,
monitored in semi-realtime with `systat -sensors` and also
logged with `sensorsd`.
Submitted by: Constantine A. Murenin <cnst@FreeBSD.org>
Sponsored by: Google Summer of Code 2007 (GSoC2007/cnst-sensors)
Mentored by: syrinx
Tested by: many
OKed by: kensmith
Obtained from: OpenBSD (parts)
fixes a bug on UP machines with SMP kernels where the idle thread
constantly switches after trying to steal work from the local cpu.
- Make the idle stealing code more robust against self selection.
- Prefer to steal from the cpu with the highest load that has at least one
transferable thread. Before we selected the cpu with the highest
transferable count which excludes bound threads.
Collaborated with: csjp
Approved by: re
to simply switch rather than lowering priority and switching. This allows
threads of equal priority to run but not lesser priority.
Discussed with: davidxu
Reported by: NIIMI Satoshi <sa2c@sa2c.net>
Approved by: re
critical_exit() owepreempt check. ULE will always use owepreempt to
preempt the idle thread. This change does not effect 4BSD since it will
never set owepreempt without PREEMPTION enabled.
- Remove some unused code from choosethread().
Discussed with: jhb
Approved by: re
not being independently freeable. This allows one to embed an mbuf in
the cluster itself. This confers the benefits of the packet zone on
all cluster sizes. Embedded mbufs currently suffer from the same
limitation that packet zone mbufs do in that one cannot disconnect
them and pass them around independently of the cluster. It would
likely be possible to eliminate this limitation in the future by
adding a second reference for the mbuf itself.
Approved by: re(gnn)
Before that fix, it was possible for the function to fail if number
of sharers changes between 'x = sx->sx_lock' step and atomic_cmpset_acq_ptr()
call.
This fixes ZFS problem when ZFS returns strange EIO errors under load.
In ZFS there is a code that depends on the fact that sx_try_slock() can
only fail if there is an exclusive owner.
Discussed with: attilio
Reviewed by: jhb
Approved by: re (kensmith)
after the switch leads to a race where the outgoing thread still owns
the local queue lock while another cpu may switch it in. This race
is only possible on machines where cpu_switch can take significantly
longer on different cpus which in practice means HTT machines with
unfair thread scheduling algorithms.
Found by: kris (of course)
Approved by: re
starvation caused by unbalanced interrupt loads.
- Change the rebalancer to work on stathz ticks but retain randomization.
- Simplify locking in tdq_idled() to use the tdq_lock_pair() rather than
complex sequences of locks to avoid deadlock.
Reported by: kris
Approved by: re
value for kern.sched.preempt_thresh appropriately. It can still by
adjusted at runtime. ULE will still use IPI_PREEMPT in certain
migration situations.
- Assert that we're not trying to compile ULE on an unsupported
architecture. To date, I believe only i386 and amd64 have implemented
the third cpu switch argument required.
Approved by: re
ways:
(1) Cached pages are no longer kept in the object's resident page
splay tree and memq. Instead, they are kept in a separate per-object
splay tree of cached pages. However, access to this new per-object
splay tree is synchronized by the _free_ page queues lock, not to be
confused with the heavily contended page queues lock. Consequently, a
cached page can be reclaimed by vm_page_alloc(9) without acquiring the
object's lock or the page queues lock.
This solves a problem independently reported by tegge@ and Isilon.
Specifically, they observed the page daemon consuming a great deal of
CPU time because of pages bouncing back and forth between the cache
queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of
this problem turned out to be a deadlock avoidance strategy employed
when selecting a cached page to reclaim in vm_page_select_cache().
However, the root cause was really that reclaiming a cached page
required the acquisition of an object lock while the page queues lock
was already held. Thus, this change addresses the problem at its
root, by eliminating the need to acquire the object's lock.
Moreover, keeping cached pages in the object's primary splay tree and
memq was, in effect, optimizing for the uncommon case. Cached pages
are reclaimed far, far more often than they are reactivated. Instead,
this change makes reclamation cheaper, especially in terms of
synchronization overhead, and reactivation more expensive, because
reactivated pages will have to be reentered into the object's primary
splay tree and memq.
(2) Cached pages are now stored alongside free pages in the physical
memory allocator's buddy queues, increasing the likelihood that large
allocations of contiguous physical memory (i.e., superpages) will
succeed.
Finally, as a result of this change long-standing restrictions on when
and where a cached page can be reclaimed and returned by
vm_page_alloc(9) are eliminated. Specifically, calls to
vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and
return a formerly cached page. Consequently, a call to malloc(9)
specifying M_NOWAIT is less likely to fail.
Discussed with: many over the course of the summer, including jeff@,
Justin Husted @ Isilon, peter@, tegge@
Tested by: an earlier version by kris@
Approved by: re (kensmith)
- Improve load long-term load balancer by always IPIing exactly once.
Previously the delay after rebalancing could cause problems with
uneven workloads.
- Allow nice to have a linear effect on the interactivity score. This
allows negatively niced programs to stay interactive longer. It may be
useful with very expensive Xorg servers under high loads. In general
it should not be necessary to alter the nice level to improve interactive
response. We may also want to consider never allowing positively niced
processes to become interactive at all.
- Initialize ccpu to 0 rather than 0.0. The decimal point was leftover
from when the code was copied from 4bsd. ccpu is 0 in ULE because ULE
only exports weighted cpu values.
Reported by: Steve Kargl (Load balancing problem)
Approved by: re
changes the units from seconds to the value of 'ticks' when swapped
in/out. ULE does not have a periodic timer that scans all threads in
the system and as such maintaining a per-second counter is difficult.
- Change computations requiring the unit in seconds to subtract ticks
and divide by hz. This does make the wraparound condition hz times
more frequent but this is still in the range of several months to
years and the adverse effects are minimal.
Approved by: re
In particular:
- smp_tlb_mtx is no longer used, so it is axed.
- smp rendezvous lock isn't really a leaf spin-mutex. Its bad placement in
the table, however, has been the source of a false positive LOR reporting
with the dt_lock. However, smp rendezvous lock would have had sched_lock
there for older lock, so it wasn't still a leaf lock.
- allpmaps is only used in ia32 architecture, so it is inserted in the
appropriate stub.
Addictionally:
- kse_zombie_lock is no longer present, so its definition is axed out.
- zombie_lock doesn't need to have an exported symbol, so just let's it be
declared as static.
Tested by: kris
Approved by: jeff (mentor)
Approved by: re
- p_sflag was mostly protected by PROC_LOCK rather than the PROC_SLOCK or
previously the sched_lock. These bugs have existed for some time.
- Allow swapout to try each thread in a process individually and then
swapin the whole process if any of these fail. This allows us to move
most scheduler related swap flags into td_flags.
- Keep ki_sflag for backwards compat but change all in source tools to
use the new and more correct location of P_INMEM.
Reported by: pho
Reviewed by: attilio, kib
Approved by: re (kensmith)
per-primitive macros like MTX_NOPROFILE, SX_NOPROFILE or RW_NOPROFILE) is
not really honoured. In particular lock_profile_obtain_lock_failure() and
lock_profile_obtain_lock_success() are naked respect this flag.
The bug leads to locks marked with no-profiling to be profiled as well.
In the case of the clock_lock, used by the timer i8254 this leads to
unpredictable behaviour both on amd64 and ia32 (double faults panic,
sudden reboots, etc.). The amd64 clock_lock is also not marked as
not profilable as it should be.
Fix these bugs adding proper checks in the lock profiling code and at
clock_lock initialization time.
i8254 bug pointed out by: kris
Tested by: matteo, Giuseppe Cocomazzi <sbudella at libero dot it>
Approved by: jeff (mentor)
Approved by: re
races for some struct thread members.
More specifically, this bug seems responsible for some memory dumping
problems people were experiencing.
Fix this adding correct thread locking.
Tested by: rwatson
Submitted by: tegge
Approved by: jeff
Approved by: re
prevents insmntque() from placing reallocated syncer vnode on mount
list, that causes panic in vfs_allocate_syncvnode().
Introduce MNTK_NOINSMNTQ flag, that marks the period when instmntque is
not allowed to success, instead of MNTK_UNMOUNT. The MNTK_NOINSMNTQ is
set and cleared simultaneously with MNTK_UNMOUNT, except on umount error
path, where it is cleaned just before the syncer vnode is going to be
allocated.
Reported by: Peter Jeremy <peterjeremy optushome com au>
Suggested by: tegge
Approved by: re (rwatson)
topology foo functions.
Working at the patch for topology problems in ia32/amd64 evicted some
problems regarding functions ordering in the SI_SUB_CPU family of
SYSINIT'ed subsystems.
In order to avoid problems with new modified to involved functions, a
correct ordering is not semantically specified for SI_SUB_CPU functions
(for a larger view of the issue please visit:
http://lists.freebsd.org/pipermail/freebsd-current/2007-July/075409.html )
Discussed with: peter
Tested by: kris, Rui Paulo <rpaulo@FreeBSD.org>
Approved by: jeff
Approved by: re
point to mac_check_vnode_unlink(), reflecting UNIX naming conventions.
This is the first of several commits to synchronize the MAC Framework
in FreeBSD 7.0 with the MAC Framework as it will appear in Mac OS X
Leopard.
Reveiwed by: csjp, Samy Bahra <sbahra at gwu dot edu>
Submitted by: Jacques Vidrine <nectar at apple dot com>
Obtained from: Apple Computer, Inc.
Sponsored by: SPARTA, SPAWAR
Approved by: re (bmah)
used, rather than the one passed via 'req', which may not reflect a
rewrite. This call to useracc() is redundant to validation performed by
later copyin()/copyout() calls, so there isn't a security issue here,
but this could technically lead to excessive validation of addresses if
the length in newlen is shorter than req.newlen.
Approved by: re (kensmith)
Reviewed by: jhb
Submitted by: Constantine A. Murenin <cnst+freebsd@bugmail.mojo.ru>
Sponsored by: Google Summer of Code 2007
the callout_lock spin lock and the sleepqueue spin locks. In the fix,
callout_drain() has to drop the callout_lock so it can acquire the
sleepqueue lock. The state of the callout can change while the
callout_lock is held however (for example, it can be rescheduled via
callout_reset()). The previous code assumed that the only state change
that could happen is that the callout could finish executing. This change
alters callout_drain() to effectively restart and recheck everything
after it acquires the sleepqueue lock thus handling all the possible
states that the callout could be in after any changes while callout_lock
was dropped.
Approved by: re (kensmith)
Tested by: kris
ktruserret() is invoked, an unlocked check of the per-process queue
is performed inline, thus, we don't lock the ktrace_sx on every userret().
Pointy hat to: jhb
Approved by: re (kensmith)
Pointy hat recovered from: rwatson
64-bit counters) to a 4.x statfs structure (with long-sized counters).
- For block counters, we scale up the block size sufficiently large so
that the resulting block counts fit into a the long-sized (long for the
ABI, so 32-bit in freebsd32) counters. In 4.x the NFS client's statfs
VOP did this already. This can lie about the block size to 4.x binaries,
but it presents a more accurate picture of the ratios of free and
available space.
- For non-block counters, fix the freebsd32 stats converter to cap the
values at INT32_MAX rather than losing the upper 32-bits to match the
behavior of the 4.x statfs conversion routine in vfs_syscalls.c
Approved by: re (kensmith)
the last message on the send stream was "null" but still
there, a state we allow, we could get hung and not clean
it up and wait for the shutdown guard timer to clear the
association without a graceful close. Fix this so that
that we properly clean up.
- Added support for Multiple ASCONF per new RFC. We only
(so far) accept input of these and cannot yet generate
a multi-asconf.
- Sysctl'd support for experimental Fast Handover feature. Always
disabled unless sysctl or socket option changes to enable.
- Error case in add-ip where the peer supports AUTH and ADD-IP
but does NOT require AUTH of ASCONF/ASCONF-ACK. We need to
ABORT in this case.
- According to the Kyoto summit of socket api developers
(Solaris, Linux, BSD). We need to have:
o non-eeor mode messages be atomic - Fixed
o Allow implicit setup of an assoc in 1-2-1 model if
using the sctp_**() send calls - Fixed
o Get rid of HAVE_XXX declarations - Done
o add a sctp_pr_policy in hole in sndrcvinfo structure - Done
o add a PR_SCTP_POLICY_VALID type flag - yet to-do in a future patch!
- Optimize sctp6 calls to reuse code in sctp_usrreq. Also optimize
when we close sending out the data and disabling Nagle.
- Change key concatenation order to match the auth RFC
- When sending OOTB shutdown_complete always do csum.
- Don't send PKT-DROP to a PKT-DROP
- For abort chunks just always checksums same for
shutdown-complete.
- inpcb_free front state had a bug where in queue
data could wedge an assoc. We need to just abandon
ones in front states (free_assoc).
- If a peer sends us a 64k abort, we would try to
assemble a response packet which may be larger than
64k. This then would be dropped by IP. Instead make
a "minimum" size for us 64k-2k (we want at least
2k for our initack). If we receive such an init
discard it early without all the processing.
- When we peel off we must increment the tcb ref count
to keep it from being freed from underneath us.
- handling fwd-tsn had bugs that caused memory overwrites
when given faulty data, fixed so can't happen and we
also stop at the first bad stream no.
- Fixed so comm-up generates the adaption indication.
- peeloff did not get the hmac params copied.
- fix it so we lock the addr list when doing src-addr selection
(in future we need to use a multi-reader/one writer lock here)
- During lowlevel output, we could end up with a _l_addr set
to null if the iterator is calling the output routine. This
means we would possibly crash when we gather the MTU info.
Fix so we only do the gather where we have a src address
cached.
- we need to be sure to set abort flag on conn state when
we receive an abort.
- peeloff could leak a socket. Moved code so the close will
find the socket if the peeloff fails (uipc_syscalls.c)
Approved by: re@freebsd.org(Ken Smith)
aio_proc_rundown.
Do not allow for zero-length read to be passed to the fo_read file method
by aio.
Reported and tested by: Peter Holm
Approved by: re (kensmith)
of the bits we want to ignore on the first pass rather than doing a
linear scan. This puts us within a few instructions of the cost of
runq_findbit() and removes this function from the top of profiling output
for context switch heavy workloads.
Approved by: re
on 2cpu machines by reducing it to 1 by default. This improves loaded
operation on 8cpu machines by increasing it to 3 where the extra idle
time is not as critical.
Approved by: re
have caused a hang, but we got lucky with the available multi-CPU states
on actual hardware.
Submitted by: Bjorn Koenig <bkoenig / alpha-tierchen.de>
Approved by: re
MFC after: 3 days
% mount | grep home
/dev/ad4s1e on /home (ufs, local, noatime, soft-updates)
% mount -u -o atime /home
% mount | grep home
/dev/ad4s1e on /home (ufs, local, soft-updates)
Restore this behavior for on 7.x for the following mount options:
noatime, noclusterr, noclusterw, noexec, nosuid, nosymfollow
In addition, on 7.x, the following are equivalent:
mount -u -o atime /home
mount -u -o nonoatime /home
Ideally, when we introduce new mount options, we should avoid
options starting with "no". :)
Requested by: jhb
Reported by: Karol Kwiat <karol.kwiat gmail com>, Scott Hetzel <swhetzel gmail com>
Approved by: re (bmah)
Proxy commit for: rodrigc
previously conditionally acquired Giant based on debug.mpsafenet. As that
has now been removed, they are no longer required. Removing them
significantly simplifies error-handling in the socket layer, eliminated
quite a bit of unwinding of locking in error cases.
While here clean up the now unneeded opt_net.h, which previously was used
for the NET_WITH_GIANT kernel option. Clean up some related gotos for
consistency.
Reviewed by: bz, csjp
Tested by: kris
Approved by: re (kensmith)
tdq_group structure. Hyper-threaded cores won't really benefit from
seperate locks anyway.
- Seperate out the migration case from sched_switch to simplify the main
switch code. We only migrate here if called via sched_bind().
- When preempted place the preempted thread back in the same queue at
the head.
- Improve the cpu group and topology infrastructure.
Tested by: many on current@
Approved by: re
framework for non-MPSAFE network protocols:
- Remove debug_mpsafenet variable, sysctl, and tunable.
- Remove NET_NEEDS_GIANT() and associate SYSINITSs used by it to force
debug.mpsafenet=0 if non-MPSAFE protocols are compiled into the kernel.
- Remove logic to automatically flag interrupt handlers as non-MPSAFE if
debug.mpsafenet is set for an INTR_TYPE_NET handler.
- Remove logic to automatically flag netisr handlers as non-MPSAFE if
debug.mpsafenet is set.
- Remove references in a few subsystems, including NFS and Cronyx drivers,
which keyed off debug_mpsafenet to determine various aspects of their own
locking behavior.
- Convert NET_LOCK_GIANT(), NET_UNLOCK_GIANT(), and NET_ASSERT_GIANT into
no-op's, as their entire behavior was determined by the value in
debug_mpsafenet.
- Alias NET_CALLOUT_MPSAFE to CALLOUT_MPSAFE.
Many remaining references to NET_.*_GIANT() and NET_CALLOUT_MPSAFE are still
present in subsystems, and will be removed in followup commits.
Reviewed by: bz, jhb
Approved by: re (kensmith)
should call uma_zfree() with various spinlock helds. Rearranging the
code would not help here because we cannot break atomicity respect
prcess spinlock, so the only one choice we have is to defer the operation.
In order to do this use a global queue synchronized through the kse_lock
spinlock which is freed at any thread_alloc() / thread_wait() through a
call to thread_reap().
Note that this approach is not ideal as we should want a per-process
list of zombie upcalls, but it follows initial guidelines of KSE authors.
Tested by: jkim, pav
Approved by: jeff, julian
Approved by: re
results unused; this, with -Werror option of gcc, rise a warning for gcc
which let the buildkernel to be busted.
Fix this removing upcall_free().
Reported by: various
Approved by: jeff
Approved by: re
Pointy hat to: attilio
dangerous races.
Fix this problems adding correct locking for the members of 'struct
kse_upcall' and other struct proc/struct thread related members.
For the moment, just leave ku_mflag and ku_flags "lazy" locked.
While here, cleanup the code removing the function kse_GC() (unused),
and merging upcall_link(), upcall_unlink(), upcall_stash() in their
respective callers (static functions, very short and only called in one
place).
Reported by: pav
Tested by: pav (on some pointyhat cluster nodes)
Approved by: jeff
Approved by: re
Sponsorized by: NGX Italy (http://www.ngx.it)
print a one line error message. Add some comments on not being able to
trust the day of week field (I'll act on these comments in a follow up
commit).
Approved by: re
MFC after: 3 weeks
filt_ttyrdetach() etc would later attempt to dereference cdev->si_tty,
causing a 0xdeadc0de dereference. Change kn_hook value from cdev to
struct tty to avoid dereferencing freed cdev.
In ttygone(), wake up select(), sigio and kevent() users in addition
to the queue sleepers.
Return EV_EOF from kevent filters if TS_GONE is set.
Submitted by: peter
Tested by: Peter Holm
Approved by: re (kensmith)
MFC after: 2 weeks
- Adjust lock_profiling stubs semantic in the hard functions in order to be
more accurate and trustable
- As for sx locks, disable shared paths for lock_profiling. Actually,
lock_profiling has a subtle race which makes results caming from shared
paths not completely trustable. A macro stub (LOCK_PROFILING_SHARED) can
be actually used for re-enabling this paths, but is currently intended
for developing use only.
- style(9) fixes
Approved by: jeff, kmacy, jhb[1]
Approved by: re
[1] Had initial reservations not shared by others, conceded
in the end.
machines.
- Leave the long-term load balancer running by default once per second.
- Enable stealing load from the idle thread only when the remote processor
has more than two transferable tasks. Setting this to one further
improves buildworld. Setting it higher improves mysql.
- Remove the bogus pick_zero option. I had not intended to commit this.
- Entirely disallow migration for threads with SRQ_YIELDING set. This
balances out the extra migration allowed for with the load balancers.
It also makes pick_pri perform better as I had anticipated.
Tested by: Dmitry Morozovsky <marck@rinet.ru>
Approved by: re
properly. We have to temporarily unlock the TDQ lock so we can lock
the thread and add it to the run queue. This is used only for KSE.
- When we add a thread from the tdq_move() via sched_balance() we need to
ipi the target if it's sitting in the idle thread or it'll never run.
Reported by: Rene Landan
Approved by: re
new code and third party modules which try to depend on it.
- Initialize sched_lock in sched_4bsd.c.
- Declare sched_lock in sparc64 pmap.c and assert that we're compiling
with SCHED_4BSD to prevent accidental crashes from running ULE. This
is the sole remaining file outside of the scheduler that uses the
global sched_lock.
Approved by: re
been in development for over 6 months as SCHED_SMP.
- Implement one spin lock per thread-queue. Threads assigned to a
run-queue point to this lock via td_lock.
- Improve the facility for assigning threads to CPUs now that sched_lock
contention no longer dominates scheduling decisions on larger SMP
machines.
- Re-write idle time stealing in an attempt to make it less damaging to
general performance. This is still disabled by default. See
kern.sched.steal_idle.
- Call the long-term load balancer from a callout rather than sched_clock()
so there are no locks held. This is disabled by default. See
kern.sched.balance.
- Parameterize many scheduling decisions via sysctls. Try to document
these via sysctl descriptions.
- General structural and naming cleanups.
- Document each function with comments.
Tested by: current@ amd64, x86, UP, SMP.
Approved by: re
kernels exposed by the recent fixes to resource limits for 32-bit processes
on 64-bit kernels:
- Let ABIs expose their maximum stack size via a new pointer in sysentvec
and use that in preference to maxssiz during exec() rather than always
using maxssiz for all processses.
- Apply the ABI's limit fixup to the previous stack size when adjusting
RLIMIT_STACK to determine if the existing mapping for the stack needs to
be grown or shrunk (as well as how much it should be grown or shrunk).
Approved by: re (kensmith)
- Adjust lock_profiling stubs semantic in the hard functions in order to be
more accurate and trustable
- Disable shared paths for lock_profiling. Actually, lock_profiling has a
subtle race which makes results caming from shared paths not completely
trustable. A macro stub (LOCK_PROFILING_SHARED) can be actually used for
re-enabling this paths, but is currently intended for developing use only.
- Use homogeneous names for automatic variables in hard functions regarding
lock_profiling
- Style fixes
- Add a CTASSERT for some flags building
Discussed with: kmacy, kris
Approved by: jeff (mentor)
Approved by: re
it with netipsec now that KAME IPsec is gone.
While here add missing netinet6 directories.
Add comments about the ports needed to be able to run those targets.
Reviewed by: philip
Approved by: re (rwatson)
ftruncate(), but without the pad arg.
There are several reasons for this. Consider 'mmap()'. On AMD64, the
function call (and syscall) ABI allow for 6 register arguments. Additional
arguments go on the stack. mmap(2) has 6 arguments. However, the syscall
definition has an extra 'int pad' argument. This pushes it to 7 arguments,
which means one must spill into the memory stack. Since the kernel API
doesn't match userland API, we have a hack in libc - libc/sys/mmap.c.
This implements the userland API by calling __syscall() with an extra
argument and the pad argument, for a total of 8 args. This is all
unnecessary and inconvenient for several things, including the kernel's
syscall handler code which now has to handle merging stack arguments with
register arguments. It is a big deal for certain 3rd party code.
I'm adding libc glue to make the transition totally painless. I had
intended to mark the old syscalls as COMPAT6, but the potential to shoot
your feet by building a new kernel without COMPAT_FREEBSD6 but with a
slighly older userland was too great. For now, they have manual
"freebsd6_" prefixes rather than being COMPAT6. They will go back to
being marked 'COMPAT6' after 7-stable starts.
Approved by: re (kensmith)
Also, change the visibility of compat syscalls a slightly. Compat
syscalls were missing from 'syscalls.h' entirely. This additionally adds
them with their compat prefix. eg: SYS_freebsd6_mmap.
Also, the syscalls.c names strings have different prefixes to differentiate
syscalls. Instead of several "old.mmap" strings, there will now be a
"compat.mmap" and "compat6.mmap" etc. Before, both would have had the
same "old.mmap" label.
Approved by: re
shall not be called while holding cdev mutex. devfs_inos unrhdr has cdev as
mutex, thus creating this LOR situation.
Postpone calling free() in kern/subr_unit.c:alloc_unr() and nested functions
until the unrhdr mutex is dropped. Save the freed items on the ppfree list
instead, and provide the clean_unrhdrl() and clean_unrhdr() functions to
clean the list.
Call clean_unrhdrl() after devfs_create() calls immediately before
dropping cdev mutex. devfs_create() is the only user of the alloc_unrl()
in the tree.
Reviewed by: phk
Tested by: Peter Holm
LOR: 80
Approved by: re (kensmith)
can acquire shared filedescriptor locks in the appropriate cases.
- Remove Giant from calls that issue ioctls. The ioctl path has been
mpsafe for some time now.
- Only acquire giant for VOP_ADVLOCK when the filesystem requires giant.
advlock is now mpsafe.
Reviewed by: rwatson
Approved by: re
to protect this datastructure instead.
- Preallocate an extra lockf structure in case we want to split a lock
on insert or delete.
- msleep() on the vnode interlock when blocking on a lock.
Reviewed by: rwatson
Approved by: re
- Use cpu_spinwait() in the spin loops in stop_cpus(), restart_cpus(), and
smp_rendezvous_action().
- Remove unneeded acq memory barriers in stop_cpus(), restart_cpus(), and
smp_rendezvous_action().
- Add an additional synch point in smp_rendezvous() to ensure that all the
CPUs will always see an up-to-date value of smp_rv_setup_func.
Reviewed by: attilio
Approved by: re (kensmith)
Tested on: alpha, amd64, i386, sparc64 SMP (for several years)
Lock cdev mutex too to close the race with tty being freed.
Relock clone_drain_lock to prevent the LOR with proctree lock, thus
add #include <fs/devfs/devfs_int.h>.
Suggested by: tegge
Debugging help and testing by: Peter Holm
Approved by: re (kensmith)
Lock Giant in the clone handler.
Use destroy_dev_sched() explicitely from pty_maybecleanup() and postpone
pty_release() until both master and slave cdevs are destroyed by setting
it as callback for destroy_dev_sched().
Debugging help and testing by: Peter Holm
Approved by: re (kensmith)
destroy_dev() is called from csw method, and no d_purge driver method is
provided. Transform the direct call to destroy_dev() into destroy_dev_sched().
Reviewed by: njl (programming interface)
Debugging help and testing by: Peter Holm
Approved by: re (kensmith)
destroy_dev() from d_close() cdev method would self-deadlock.
devfs_close() bump device thread reference counter, and destroy_dev()
sleeps, waiting for si_threadcount to reach zero for cdev without
d_purge method.
destroy_dev_sched() could be used instead from d_close(), to
schedule execution of destroy_dev() in another context. The
destroy_dev_sched_drain() function can be used to drain the scheduled
calls to destroy_dev_sched(). Similarly, drain_dev_clone_events() drains
the events clone to make sure no lingering devices are left after
dev_clone event handler deregistered.
make_dev_credf(MAKEDEV_REF) function should be used from dev_clone
event handlers instead of make_dev()/make_dev_cred() to ensure that created
device has reference counter bumped before cdev mutex is dropped inside
make_dev().
Reviewed by: tegge (early versions), njl (programming interface)
Debugging help and testing by: Peter Holm
Approved by: re (kensmith)
could lead to a deadlock).
- sleepq_set_timeout acquires callout_lock (via callout_reset()) only
with sleepq chain lock held
- msleep_spin in _callout_stop_safe lock the sleepqueue chain with
callout_lock held
In order to solve this don't use msleep_spin in _callout_stop_safe() but
use directly sleepqueues as inline msleep_spin code. Rearrange the
wakeup path in order to have it consistent too.
Reported by: kris (via stress2 test suite)
Tested by: Timothy Redaelli <drizzt@gufi.org>
Reviewed by: jhb
Approved by: jeff (mentor)
Approved by: re
This is very similar to sx_init_flags: it initializes the rwlock using
special flags passed as third argument (RW_DUPOK, RW_NOPROFILE,
RW_NOWITNESS, RW_QUIET, RW_RECURSE).
Among these, the most important new feature is probabilly that rwlocks
can be acquired recursively now (for both shared and exclusive paths).
Because of the recursion counter, the ABI is changed.
Tested by: Timothy Redaelli <drizzt@gufi.org>
Reviewed by: jhb
Approved by: jeff (mentor)
Approved by: re
Postpone call to devfs_free() after cdev mutex is dropped. Reuse
cdp_list link for queuing devices awaiting deletion in the
cdevp_free_list.
Reported by: Hans Petter Selasky <hselasky c2i net>
Tested by: Peter Holm
Approved by: re (kensmith)
MFC after: 2 weeks
a privilege is checked against the real uid rather than the effective
uid, instead decide which uid to use in priv_check_cred() based on the
privilege passed in. We use the real uid for PRIV_MAXFILES,
PRIV_MAXPROC, and PRIV_PROC_LIMIT. Remove the definition of
SUSER_RUID; there are now no flags defined for priv_check_cred().
Obtained from: TrustedBSD Project
- Move the rtc_mtx spin lock out from under #ifdef SMP as it's just
not SMP-specific.
- Add a new spin lock pcib_mtx for locking "fast" interrupt handlers
of host-to-PCI bridge drivers on sparc64.
- In tdq_choose() only assert that a thread does not have too high a
priority (low value) for the queue we removed it from. This will catch
bugs in priority elevation. It's not a serious error for the thread
to have too low a priority as we don't change queues in this case as
an optimization.
Reported by: kris
or idle priority of another process owned by the same user. This means
that privilege in rtprio(2) (and rtprio_thread(2)) is required indirectly
via p_cansched(9) or directly to set realtime/idle privilege, rather than
directly affecting target process authorization.
- Depessimize userret() in kernels where KTRACE is enabled by doing an
unlocked check of the per-process queue of pending events before
acquiring any locks. Previously ktr_userret() unconditionally acquired
the global ktrace_sx lock on every return to userland for every thread,
even if ktrace wasn't enabled for the thread.
- Optimize the locking in exit() to first perform an unlocked read of
p_traceflag to see if ktrace is enabled and only acquire locks and
teardown ktrace if the test succeeds. Also, explicitly disable tracing
before draining any pending events so the pending events actually get
written out. The unlocked read is safe because proc lock is acquired
earlier after single-threading so p_traceflag can't change between then
and this check (well, it can currently due to a bug in ktrace I will fix
next, but that race existed prior to this change as well).
Reviewed by: rwatson
during execve() when turning off tracing due to executing a setuid binary
as non-root. Previously this could fail to acquire Giant and fail an
assertion if the ktrace file was on a non-MPSAFE filesystem and the
executable was on an MPSAFE filesystem.
MFC after: 3 days
Reported by: kris
- Remove unused kse fields from struct proc.
- Group remaining fields and #ifdef KSE them.
- Move some kern_kse.c only prototypes out of proc and into kern_kse.
Discussed with: Julian
- Add a count of exiting threads, p_exitthreads, to struct proc.
- Increment p_exithreads when we set the deadthread in thread_exit().
- When we thread_stash() a deadthread use an atomic to drop the count.
- Spin until the p_exithreads count reaches 0 in thread_wait().
- Lock the last exiting thread momentarily to be certain that it has
exited cpu_throw().
- Restructure thread_wait(). It does not need a loop as there will only
ever be one thread.
Tested by: moose@opera.com
Reported by: kris, moose@opera.com
some cases, move to priv_check() if it was an operation on a thread and
no other flags were present.
Eliminate caller-side jail exception checking (also now-unused); jail
privilege exception code now goes solely in kern_jail.c.
We can't yet eliminate suser() due to some cases in the KAME code where
a privilege check is performed and then used in many different deferred
paths. Do, however, move those prototypes to priv.h.
Reviewed by: csjp
Obtained from: TrustedBSD Project
o major overhaul of the way channels are handled: channels are now
fully enumerated and uniquely identify the operating characteristics;
these changes are visible to user applications which require changes
o make scanning support independent of the state machine to enable
background scanning and roaming
o move scanning support into loadable modules based on the operating
mode to enable different policies and reduce the memory footprint
on systems w/ constrained resources
o add background scanning in station mode (no support for adhoc/ibss
mode yet)
o significantly speedup sta mode scanning with a variety of techniques
o add roaming support when background scanning is supported; for now
we use a simple algorithm to trigger a roam: we threshold the rssi
and tx rate, if either drops too low we try to roam to a new ap
o add tx fragmentation support
o add first cut at 802.11n support: this code works with forthcoming
drivers but is incomplete; it's included now to establish a baseline
for other drivers to be developed and for user applications
o adjust max_linkhdr et. al. to reflect 802.11 requirements; this eliminates
prepending mbufs for traffic generated locally
o add support for Atheros protocol extensions; mainly the fast frames
encapsulation (note this can be used with any card that can tx+rx
large frames correctly)
o add sta support for ap's that beacon both WPA1+2 support
o change all data types from bsd-style to posix-style
o propagate noise floor data from drivers to net80211 and on to user apps
o correct various issues in the sta mode state machine related to handling
authentication and association failures
o enable the addition of sta mode power save support for drivers that need
net80211 support (not in this commit)
o remove old WI compatibility ioctls (wicontrol is officially dead)
o change the data structures returned for get sta info and get scan
results so future additions will not break user apps
o fixed tx rate is now maintained internally as an ieee rate and not an
index into the rate set; this needs to be extended to deal with
multi-mode operation
o add extended channel specifications to radiotap to enable 11n sniffing
Drivers:
o ath: add support for bg scanning, tx fragmentation, fast frames,
dynamic turbo (lightly tested), 11n (sniffing only and needs
new hal)
o awi: compile tested only
o ndis: lightly tested
o ipw: lightly tested
o iwi: add support for bg scanning (well tested but may have some
rough edges)
o ral, ural, rum: add suppoort for bg scanning, calibrate rssi data
o wi: lightly tested
This work is based on contributions by Atheros, kmacy, sephe, thompsa,
mlaier, kevlo, and others. Much of the scanning work was supported by
Atheros. The 11n work was supported by Marvell.
In particular:
- Add an explicative table for locking of struct vmmeter members
- Apply new rules for some of those members
- Remove some unuseful comments
Heavily reviewed by: alc, bde, jeff
Approved by: jeff (mentor)
This patch fixes places where they should be called atomically changing
their locking requirements (both assume per-proc spinlock held) and
introducing rufetchcalc which wrappers both calls to be performed in
atomic way.
Reviewed by: jeff
Approved by: jeff (mentor)
- Unsafeness on ruadd() in thread_exit()
- Unatomicity of thread_exiit() in the exit1() operations
This patch addresses these problems allocating p_fd as part of the
process and modifying the way it is accessed.
A small chunk of this patch, resolves a race about p_state in kern_wait(),
since we have to be sure about the zombif-ing process.
Submitted by: jeff
Approved by: jeff (mentor)
embedded storage in struct ucred. This allows audit state to be cached
with the thread, avoiding locking operations with each system call, and
makes it available in asynchronous execution contexts, such as deep in
the network stack or VFS.
Reviewed by: csjp
Approved by: re (kensmith)
Obtained from: TrustedBSD Project
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
