Commit Graph

2289 Commits

Author SHA1 Message Date
John Baldwin
40ad471f8e Use the read_cycle_count() function recently added for cpu_ticks() for
get_cyclecount() as that results in a saner value and makes schedgraph
much happier on Alpha.  (schedgraph doesn't handle the fact that the
counters are out of sync though)
2006-03-28 21:20:12 +00:00
Alexander Leidinger
62624b782d Remove some dummy functions, we have corresponding real ones now. 2006-03-21 21:08:02 +00:00
Alexander Leidinger
f50143e803 regen 2006-03-20 19:48:02 +00:00
Alexander Leidinger
61da9d97fb Fix tinderbox on alpha.
Tested by:	cross-compile
2006-03-20 19:46:56 +00:00
Alexander Leidinger
c85625bfe7 regen 2006-03-18 20:49:01 +00:00
Alexander Leidinger
d4a3f5ddb6 Fixup some problems in my previous commit (COMPAT_43).
Pointyhat to:	netchild
2006-03-18 20:47:36 +00:00
Alexander Leidinger
1f7642e058 regen after COMPAT_43 removal 2006-03-18 18:24:38 +00:00
Alexander Leidinger
5c8919adf4 Get rid of the need of COMPAT_43 in the linuxolator.
Submitted by:	Divacky Roman <xdivac02@stud.fit.vutbr.cz>
Obtained from:	DragonFly (some parts)
2006-03-18 18:20:17 +00:00
John Baldwin
0499f1d8a7 Use the Alpha PCC as a cpu ticker for process runtime accounting. This is
slightly more tricky than on x86 as although the PCC is 64-bits, it is not
a simple 64-bit counter like the TSC.  Instead, the upper 32-bits have
PAL-defined behavior and the lower 32-bits run as a free-running 32-bit
counter.  To handle this, we detect overflows by maintaining a small amount
of per-cpu state and use this to simulate the upper 32-bits of the counter
providing a full 64-bit counter to the consumers of cpu_ticks().
2006-03-07 22:12:09 +00:00
John Baldwin
28c2f17ccb - Simplify the i8254 timecounter for the alpha since we don't actually have
an interrupt handler for the i8254.  (Our clock interrupts come from
  elsewhere.)  Instead, use the same algo that i386 uses when the lapic
  timer is in use.  This lets us remove a lot of cruft that tried to handle
  the i8254 interrupts that we weren't even using or setting up a handler
  for.
- G/C a bunch of unused cruft while I'm here.
- Fix the code to not use the rpcc timecounter (similar to TSC) on SMP
  machines to only disable that timecounter if more than one CPU is in
  use by the kernel.  Previously, a UP kernel on a machine with multiple
  CPUs would needlessly disable this timecounter.

MFC after:	1 week
2006-03-07 21:44:20 +00:00
John Baldwin
06ad42b2f7 Close some races between procfs/ptrace and exit(2):
- Reorder the events in exit(2) slightly so that we trigger the S_EXIT
  stop event earlier.  After we have signalled that, we set P_WEXIT and
  then wait for any processes with a hold on the vmspace via PHOLD to
  release it.  PHOLD now KASSERT()'s that P_WEXIT is clear when it is
  invoked, and PRELE now does a wakeup if P_WEXIT is set and p_lock drops
  to zero.
- Change proc_rwmem() to require that the processing read from has its
  vmspace held via PHOLD by the caller and get rid of all the junk to
  screw around with the vmspace reference count as we no longer need it.
- In ptrace() and pseudofs(), treat a process with P_WEXIT set as if it
  doesn't exist.
- Only do one PHOLD in kern_ptrace() now, and do it earlier so it covers
  FIX_SSTEP() (since on alpha at least this can end up calling proc_rwmem()
  to clear an earlier single-step simualted via a breakpoint).  We only
  do one to avoid races.  Also, by making the EINVAL error for unknown
  requests be part of the default: case in the switch, the various
  switch cases can now just break out to return which removes a _lot_ of
  duplicated PRELE and proc unlocks, etc.  Also, it fixes at least one bug
  where a LWP ptrace command could return EINVAL with the proc lock still
  held.
- Changed the locking for ptrace_single_step(), ptrace_set_pc(), and
  ptrace_clear_single_step() to always be called with the proc lock
  held (it was a mixed bag previously).  Alpha and arm have to drop
  the lock while the mess around with breakpoints, but other archs
  avoid extra lock release/acquires in ptrace().  I did have to fix a
  couple of other consumers in kern_kse and a few other places to
  hold the proc lock and PHOLD.

Tested by:	ps (1 mostly, but some bits of 2-4 as well)
MFC after:	1 week
2006-02-22 18:57:50 +00:00
John Baldwin
414c4ab4c5 Fix the hw.realmem sysctl. The global realmem variable is a count of
pages, not a count of bytes.  The sysctl handler for hw.realmem already
uses ctob() to convert realmem from pages to bytes.  Thus, on archs that
were storing a byte count in the realmem variable, hw.realmem was inflated.

Reported by:	Valerio daelli valerio dot daelli at gmail dot com (alpha)
MFC after:	3 days
2006-02-14 14:50:11 +00:00
Poul-Henning Kamp
eb2da9a51f Simplify system time accounting for profiling.
Rename struct thread's td_sticks to td_pticks, we will need the
other name for more appropriately named use shortly.  Reduce it
from uint64_t to u_int.

Clear td_pticks whenever we enter the kernel instead of recording
its value as reference for userret().  Use the absolute value of
td->pticks in userret() and eliminate third argument.
2006-02-08 08:09:17 +00:00
Poul-Henning Kamp
5b1a8eb397 Modify the way we account for CPU time spent (step 1)
Keep track of time spent by the cpu in various contexts in units of
"cputicks" and scale to real-world microsec^H^H^H^H^H^H^H^Hclock_t
only when somebody wants to inspect the numbers.

For now "cputicks" are still derived from the current timecounter
and therefore things should by definition remain sensible also on
SMP machines.  (The main reason for this first milestone commit is
to verify that hypothesis.)

On slower machines, the avoided multiplications to normalize timestams
at every context switch, comes out as a 5-7% better score on the
unixbench/context1 microbenchmark.  On more modern hardware no change
in performance is seen.
2006-02-07 21:22:02 +00:00
John Baldwin
8917b8d28c - Always call exec_free_args() in kern_execve() instead of doing it in all
the callers if the exec either succeeds or fails early.
- Move the code to call exit1() if the exec fails after the vmspace is
  gone to the bottom of kern_execve() to cut down on some code duplication.
2006-02-06 22:06:54 +00:00
Robert Watson
6b28a1b2a3 Regenerate. 2006-02-06 01:16:00 +00:00
Robert Watson
4790bb223e Reflect fix in Linux setfsgid() event name from OpenBSM in the alpha
linux system call table.

Obtained from:	TrustedBSD Project
2006-02-06 01:13:47 +00:00
Robert Watson
01bcdff15d Assign audit identifiers to alpha/linux system calls so that they will
be audited.

Obtained from:	TrustedBSD Project
2006-02-04 14:03:22 +00:00
Poul-Henning Kamp
d3e64681d6 Move the old BSD4.3 tty compatibility from (!BURN_BRIDGES && COMPAT_43)
to COMPAT_43TTY.

Add COMPAT_43TTY to NOTES and */conf/GENERIC

Compile tty_compat.c only under the new option.

Spit out
	#warning "Old BSD tty API used, please upgrade."
if ioctl_compat.h gets #included from userland.
2006-01-10 09:19:10 +00:00
Warner Losh
d5e61c97a6 By popular demand, move __HAVE_ACPI and __PCI_REROUTE_INTERRUPT into
param.h.  Per request, I've placed these just after the
_NO_NAMESPACE_POLLUTION ifndef.  I've not renamed anything yet, but
may since we don't need the __.

Submitted by: bde, jhb, scottl, many others.
2006-01-09 06:05:57 +00:00
Warner Losh
501755f4f6 Define __HAVE_ACPI and/or __PCI_REROUTE_INTERRUPT, as appropriate for
each platform.  These will be used in the pci code in preference to
the complicated #ifdefs we have there now.
2006-01-01 20:59:28 +00:00
Alexander Leidinger
ef39c05baa MI changes:
- provide an interface (macros) to the page coloring part of the VM system,
   this allows to try different coloring algorithms without the need to
   touch every file [1]
 - make the page queue tuning values readable: sysctl vm.stats.pagequeue
 - autotuning of the page coloring values based upon the cache size instead
   of options in the kernel config (disabling of the page coloring as a
   kernel option is still possible)

MD changes:
 - detection of the cache size: only IA32 and AMD64 (untested) contains
   cache size detection code, every other arch just comes with a dummy
   function (this results in the use of default values like it was the
   case without the autotuning of the page coloring)
 - print some more info on Intel CPU's (like we do on AMD and Transmeta
   CPU's)

Note to AMD owners (IA32 and AMD64): please run "sysctl vm.stats.pagequeue"
and report if the cache* values are zero (= bug in the cache detection code)
or not.

Based upon work by:	Chad David <davidc@acns.ab.ca> [1]
Reviewed by:		alc, arch (in 2004)
Discussed with:		alc, Chad David, arch (in 2004)
2005-12-31 14:39:20 +00:00
Maxim Sobolev
900b28f9f6 Remove kern.elf32.can_exec_dyn sysctl. Instead extend Brandinfo structure
with flags bitfield and set BI_CAN_EXEC_DYN flag for all brands that usually
allow executing elf dynamic binaries (aka shared libraries). When it is
requested to execute ET_DYN elf image check if this flag is on after we
know the elf brand allowing execution if so.

PR:		kern/87615
Submitted by:	Marcin Koziej <creep@desk.pl>
2005-12-26 21:23:57 +00:00
John Baldwin
b439e431bf Tweak how the MD code calls the fooclock() methods some. Instead of
passing a pointer to an opaque clockframe structure and requiring the
MD code to supply CLKF_FOO() macros to extract needed values out of the
opaque structure, just pass the needed values directly.  In practice this
means passing the pair (usermode, pc) to hardclock() and profclock() and
passing the boolean (usermode) to hardclock_cpu() and hardclock_process().
Other details:
- Axe clockframe and CLKF_FOO() macros on all architectures.  Basically,
  all the archs were taking a trapframe and converting it into a clockframe
  one way or another.  Now they can just extract the PC and usermode values
  directly out of the trapframe and pass it to fooclock().
- Renamed hardclock_process() to hardclock_cpu() as the latter is more
  accurate.
- On Alpha, we now run profclock() at hz (profhz == hz) rather than at
  the slower stathz.
- On Alpha, for the TurboLaser machines that don't have an 8254
  timecounter, call hardclock() directly.  This removes an extra
  conditional check from every clock interrupt on Alpha on the BSP.
  There is probably room for even further pruning here by changing Alpha
  to use the simplified timecounter we use on x86 with the lapic timer
  since we don't get interrupts from the 8254 on Alpha anyway.
- On x86, clkintr() shouldn't ever be called now unless using_lapic_timer
  is false, so add a KASSERT() to that affect and remove a condition
  to slightly optimize the non-lapic case.
- Change prototypeof  arm_handler_execute() so that it's first arg is a
  trapframe pointer rather than a void pointer for clarity.
- Use KCOUNT macro in profclock() to lookup the kernel profiling bucket.

Tested on:	alpha, amd64, arm, i386, ia64, sparc64
Reviewed by:	bde (mostly)
2005-12-22 22:16:09 +00:00
Marcel Moolenaar
757686b115 Make our ELF64 type definitions match standards. In particular this
means:
o  Remove Elf64_Quarter,
o  Redefine Elf64_Half to be 16-bit,
o  Redefine Elf64_Word to be 32-bit,
o  Add Elf64_Xword and Elf64_Sxword for 64-bit entities,
o  Use Elf_Size in MI code to abstract the difference between
   Elf32_Word and Elf64_Word.
o  Add Elf_Ssize as the signed counterpart of Elf_Size.

MFC after: 2 weeks
2005-12-18 04:52:37 +00:00
John Baldwin
410d857972 Remove linux_mib_destroy() (which I actually added in between 5.0 and 5.1)
which existed to cleanup the linux_osname mutex.  Now that MTX_SYSINIT()
has grown a SYSUNINIT to destroy mutexes on unload, the extra destroy here
was redundant and resulted in panics in debug kernels.

MFC after:	1 week
Reported by:	Goran Gajic ggajic at afrodita dot rcub dot bg dot ac dot yu
2005-12-15 16:30:41 +00:00
John Baldwin
3ca629a373 Whitespace. 2005-12-14 21:42:12 +00:00
John Baldwin
696effb697 - Cleanup whitespace and extra ()s in vtophys() macros.
- Move vtophys() macros next to vtopte() where vtopte() exists to match
  comments above vtopte().
- Remove references to the alternate address space in the comment above
  vtopte().  amd64 never had the alternate address space, and i386 lost it
  prior to PAE support being added.
- s/entires/entries/ in comments.

Reviewed by:	alc
2005-12-06 21:09:01 +00:00
Ruslan Ermilov
224d140293 Drop _MACHINE_ARCH and _MACHINE defines (not to be confused with
MACHINE_ARCH and MACHINE).  Their purpose was to be able to test
in cpp(1), but cpp(1) only understands integer type expressions.
Using such unsupported expressions introduced a number of subtle
bugs, which were discovered by compiling with -Wundef.
2005-12-06 13:27:21 +00:00
Ruslan Ermilov
44e09d2fa2 Fix -Wundef warnings from compiling GENERIC and LINT kernels of
all architectures.
2005-12-06 11:19:37 +00:00
Alan Cox
4e067a8592 Change pmap_enter_quick() to use the vm_prot_t parameter introduced in
revision 1.179 to correctly set/clear execute permission on the mapping
it creates.  Thus, mmap(2)ing a memory resident file will not result in
the file being mapped with execute permission when execute permission was
not requested.

Eliminate an unneeded Instruction Memory Barrier (IMB) in
pmap_enter_quick().  Since there was no previous (instruction) mapping
for the given virtual address prior to pmap_enter_quick(), there can be
no instructions from the given virtual address in the pipeline that need
flushing.

MFC after: 1 week
2005-12-02 18:02:54 +00:00
Ruslan Ermilov
6646524f34 - Allow duplicate "machine" directives with the same arguments.
- Move existing "machine" directives to DEFAULTS.
2005-11-27 23:17:00 +00:00
John Baldwin
7417e80b4e Don't enable PUC_FASTINTR by default in the source. Instead, enable it
via the DEFAULTS kernel configs.  This allows folks to turn it that option
off in the kernel configs if desired without having to hack the source.
This is especially useful since PUC_FASTINTR hangs the kernel boot on my
ultra60 which has two uart(4) devices hung off of a puc(4) device.

I did not enable PUC_FASTINTR by default on powerpc since powerpc does not
currently allow sharing of INTR_FAST with non-INTR_FAST like the other
archs.
2005-11-21 20:22:35 +00:00
John Baldwin
d0750fb9b0 Create DEFAULTS files for alpha, ia64, powerpc, and sparc64 and move
'device mem' over from GENERIC to DEFAULTS to be consistent with i386 and
amd64.  Additionally, on ia64 enable ACPI by default since ia64 requires
acpi.
2005-11-21 20:17:46 +00:00
Alan Cox
97a0c226d6 Eliminate pmap_init2(). It's no longer used. 2005-11-20 06:09:49 +00:00
Marcel Moolenaar
93eed66913 Improve inittodr(). Assume the real-time clock is reliable and only
use the base time in case the real-time clock is bogus or behind the
base time. Most importantly, don't sanity-check the base time up front
because it may be zero. This is not a preposterous condition. It just
means that none of the file systems have their mount time updated.

MFC after: 1 week
2005-11-20 01:31:29 +00:00
Alan Cox
65336314cf In get_pv_entry() use PMAP_LOCK() instead of PMAP_TRYLOCK() when deadlock
cannot possibly occur.
2005-11-13 02:17:05 +00:00
Alan Cox
7a35a21e7b Reimplement the reclamation of PV entries. Specifically, perform
reclamation synchronously from get_pv_entry() instead of
asynchronously as part of the page daemon.  Additionally, limit the
reclamation to inactive pages unless allocation from the PV entry zone
or reclamation from the inactive queue fails.  Previously, reclamation
destroyed mappings to both inactive and active pages.  get_pv_entry()
still, however, wakes up the page daemon when reclamation occurs.  The
reason being that the page daemon may move some pages from the active
queue to the inactive queue, making some new pages available to future
reclamations.

Print the "reclaiming PV entries" message at most once per minute, but
don't stop printing it after the fifth time.  This way, we do not give
the impression that the problem has gone away.

Reviewed by: tegge
2005-11-09 08:19:21 +00:00
Marcel Moolenaar
38195fdcaf Add uart(4). When both sio(4) and uart(4) can handle a serial port,
sio(4) will claim it. This change therefore only affects how ports
are handled when they are not claimed by sio(4), and in principle
will improve hardware support.

MFC after: 2 months
2005-11-05 19:48:53 +00:00
Alan Cox
e9cb1037da Begin and end the initialization of pvzone in pmap_init().
Previously, pvzone's initialization was split between pmap_init() and
pmap_init2().  This split initialization was the underlying cause of
some UMA panics during initialization.  Specifically, if the UMA boot
pages was exhausted before the pvzone was fully initialized, then UMA,
through no fault of its own, would use an inappropriate back-end
allocator leading to a panic.  (Previously, as a workaround, we have
increased the UMA boot pages.)  Fortunately, there is no longer any
reason that pvzone's initialization cannot be completed in
pmap_init().

Eliminate a check for whether pv_entry_high_water has been initialized
or not from get_pv_entry().  Since pvzone's initialization is
completed in pmap_init(), this check is no longer needed.

Use cnt.v_page_count, the actual count of available physical pages,
instead of vm_page_array_size to compute the maximum number of pv
entries.

Introduce the vm.pmap.pv_entries tunable on alpha and ia64.

Eliminate some unnecessary white space.

Discussed with: tegge (item #1)
Tested by: marcel (ia64)
2005-11-04 18:03:24 +00:00
John Baldwin
091e8307d0 Add stoppcbs[] arrays on Alpha and sparc64 and have each CPU save its
current context in the IPI_STOP handler so that we can get accurate stack
traces of threads on other CPUs on these two archs like we do now on i386
and amd64.

Tested on:	alpha, sparc64
2005-11-03 21:08:20 +00:00
Alan Cox
83ed5ec059 Instead of a panic()ing in pmap_insert_entry() if get_pv_entry() fails,
reclaim a pv entry by destroying a mapping to an inactive page.
2005-11-02 08:23:28 +00:00
Alan Cox
563d9e6341 MFamd64/i386
Eliminate unneeded diagnostic code.
2005-10-31 16:14:07 +00:00
John Baldwin
e0f66ef861 Reorganize the interrupt handling code a bit to make a few things cleaner
and increase flexibility to allow various different approaches to be tried
in the future.
- Split struct ithd up into two pieces.  struct intr_event holds the list
  of interrupt handlers associated with interrupt sources.
  struct intr_thread contains the data relative to an interrupt thread.
  Currently we still provide a 1:1 relationship of events to threads
  with the exception that events only have an associated thread if there
  is at least one threaded interrupt handler attached to the event.  This
  means that on x86 we no longer have 4 bazillion interrupt threads with
  no handlers.  It also means that interrupt events with only INTR_FAST
  handlers no longer have an associated thread either.
- Renamed struct intrhand to struct intr_handler to follow the struct
  intr_foo naming convention.  This did require renaming the powerpc
  MD struct intr_handler to struct ppc_intr_handler.
- INTR_FAST no longer implies INTR_EXCL on all architectures except for
  powerpc.  This means that multiple INTR_FAST handlers can attach to the
  same interrupt and that INTR_FAST and non-INTR_FAST handlers can attach
  to the same interrupt.  Sharing INTR_FAST handlers may not always be
  desirable, but having sio(4) and uhci(4) fight over an IRQ isn't fun
  either.  Drivers can always still use INTR_EXCL to ask for an interrupt
  exclusively.  The way this sharing works is that when an interrupt
  comes in, all the INTR_FAST handlers are executed first, and if any
  threaded handlers exist, the interrupt thread is scheduled afterwards.
  This type of layout also makes it possible to investigate using interrupt
  filters ala OS X where the filter determines whether or not its companion
  threaded handler should run.
- Aside from the INTR_FAST changes above, the impact on MD interrupt code
  is mostly just 's/ithread/intr_event/'.
- A new MI ddb command 'show intrs' walks the list of interrupt events
  dumping their state.  It also has a '/v' verbose switch which dumps
  info about all of the handlers attached to each event.
- We currently don't destroy an interrupt thread when the last threaded
  handler is removed because it would suck for things like ppbus(8)'s
  braindead behavior.  The code is present, though, it is just under
  #if 0 for now.
- Move the code to actually execute the threaded handlers for an interrrupt
  event into a separate function so that ithread_loop() becomes more
  readable.  Previously this code was all in the middle of ithread_loop()
  and indented halfway across the screen.
- Made struct intr_thread private to kern_intr.c and replaced td_ithd
  with a thread private flag TDP_ITHREAD.
- In statclock, check curthread against idlethread directly rather than
  curthread's proc against idlethread's proc. (Not really related to intr
  changes)

Tested on:	alpha, amd64, i386, sparc64
Tested on:	arm, ia64 (older version of patch by cognet and marcel)
2005-10-25 19:48:48 +00:00
Ade Lovett
8d228514fb Specifically panic() in the case where pmap_insert_entry() fails to
get a new pv under high system load where the available pv entries
have been exhausted before the pagedaemon has a chance to wake up
to reclaim some.

Prior to this, the NULL pointer dereference ended up causing
secondary panics with rather less than useful resulting tracebacks.

Reviewed by:	alc, jhb
MFC after:	1 week
2005-10-21 19:42:43 +00:00
Poul-Henning Kamp
7423b2b40c Make ttyconsolemode() call ttsetwater() so that drivers don't have to. 2005-10-16 20:58:22 +00:00
David Xu
9104847f21 1. Change prototype of trapsignal and sendsig to use ksiginfo_t *, most
changes in MD code are trivial, before this change, trapsignal and
   sendsig use discrete parameters, now they uses member fields of
   ksiginfo_t structure. For sendsig, this change allows us to pass
   POSIX realtime signal value to user code.

2. Remove cpu_thread_siginfo, it is no longer needed because we now always
   generate ksiginfo_t data and feed it to libpthread.

3. Add p_sigqueue to proc structure to hold shared signals which were
   blocked by all threads in the proc.

4. Add td_sigqueue to thread structure to hold all signals delivered to
   thread.

5. i386 and amd64 now return POSIX standard si_code, other arches will
   be fixed.

6. In this sigqueue implementation, pending signal set is kept as before,
   an extra siginfo list holds additional siginfo_t data for signals.
   kernel code uses psignal() still behavior as before, it won't be failed
   even under memory pressure, only exception is when deleting a signal,
   we should call sigqueue_delete to remove signal from sigqueue but
   not SIGDELSET. Current there is no kernel code will deliver a signal
   with additional data, so kernel should be as stable as before,
   a ksiginfo can carry more information, for example, allow signal to
   be delivered but throw away siginfo data if memory is not enough.
   SIGKILL and SIGSTOP have fast path in sigqueue_add, because they can
   not be caught or masked.
   The sigqueue() syscall allows user code to queue a signal to target
   process, if resource is unavailable, EAGAIN will be returned as
   specification said.
   Just before thread exits, signal queue memory will be freed by
   sigqueue_flush.
   Current, all signals are allowed to be queued, not only realtime signals.

Earlier patch reviewed by: jhb, deischen
Tested on: i386, amd64
2005-10-14 12:43:47 +00:00
John Baldwin
1c5b402897 Remove the hack to clear the owepreempt flag after running a fast
interrupt handler from Alpha.  Instead, expand the scheduler pinning
in the interrupt handling code so that curthread is pinned while executing
fast interrupt handlers.

MFC after:	1 week
2005-09-29 19:12:44 +00:00
Robert Watson
5f419982c2 Back out alpha/alpha/trap.c:1.124, osf1_ioctl.c:1.14, osf1_misc.c:1.57,
osf1_signal.c:1.41, amd64/amd64/trap.c:1.291, linux_socket.c:1.60,
svr4_fcntl.c:1.36, svr4_ioctl.c:1.23, svr4_ipc.c:1.18, svr4_misc.c:1.81,
svr4_signal.c:1.34, svr4_stat.c:1.21, svr4_stream.c:1.55,
svr4_termios.c:1.13, svr4_ttold.c:1.15, svr4_util.h:1.10,
ext2_alloc.c:1.43, i386/i386/trap.c:1.279, vm86.c:1.58,
unaligned.c:1.12, imgact_elf.c:1.164, ffs_alloc.c:1.133:

Now that Giant is acquired in uprintf() and tprintf(), the caller no
longer leads to acquire Giant unless it also holds another mutex that
would generate a lock order reversal when calling into these functions.
Specifically not backed out is the acquisition of Giant in nfs_socket.c
and rpcclnt.c, where local mutexes are held and would otherwise violate
the lock order with Giant.

This aligns this code more with the eventual locking of ttys.

Suggested by:	bde
2005-09-28 07:03:03 +00:00
John Baldwin
3c2bc2bf26 Add a new atomic_fetchadd() primitive that atomically adds a value to a
variable and returns the previous value of the variable.

Tested on:	i386, alpha, sparc64, arm (cognet)
Reviewed by:	arch@
Submitted by:	cognet (arm)
MFC after:	1 week
2005-09-27 17:39:11 +00:00