Commit Graph

74 Commits

Author SHA1 Message Date
Ed Schouten
c90c9021e9 Remove even more unneeded variable assignments.
kern_time.c:
- Unused variable `p'.

kern_thr.c:
- Variable `error' is always caught immediately, so no reason to
  initialize it. There is no way that error != 0 at the end of
  create_thread().

kern_sig.c:
- Unused variable `code'.

kern_synch.c:
- `rval' is always assigned in all different cases.

kern_rwlock.c:
- `v' is always overwritten with RW_UNLOCKED further on.

kern_malloc.c:
- `size' is always initialized with the proper value before being used.

kern_exit.c:
- `error' is always caught and returned immediately. abort2() never
  returns a non-zero value.

kern_exec.c:
- `len' is always assigned inside the if-statement right below it.

tty_info.c:
- `td' is always overwritten by FOREACH_THREAD_IN_PROC().

Found by:	LLVM's scan-build
2009-02-26 15:51:54 +00:00
Konstantin Belousov
b4cf0e62f4 Add sv_flags field to struct sysentvec with intention to provide description
of the ABI of the currently executing image. Change some places to test
the flags instead of explicit comparing with address of known sysentvec
structures to determine ABI features.

Discussed with:	dchagin, imp, jhb, peter
2008-11-22 12:36:15 +00:00
David Xu
7b4a950a7d Revert rev 184216 and 184199, due to the way the thread_lock works,
it may cause a lockup.

Noticed by: peter, jhb
2008-11-05 03:01:23 +00:00
David Xu
94ec9c0245 If threads limit is exceeded, increase the totoal number
of failures.
2008-10-29 12:11:48 +00:00
David Xu
3f9be10eb0 Actually, for signal and thread suspension, extra process spin lock is
unnecessary, the normal process lock and thread lock are enough. The
spin lock is still needed for process and thread exiting to mimic
single sched_lock.
2008-10-23 07:55:38 +00:00
Roman Divacky
e4866772c3 Check the result of copyin and in a case of error
return one. This prevents setting wrong priority
or (more likely) returning EINVAL.

Approved by:	kib (mentor)
2008-10-13 21:04:52 +00:00
David Xu
3bba58f287 Fix compiling problem. 2008-04-29 05:48:05 +00:00
David Xu
34d05d83f6 Remove commented out code, thread suspension is done in thread library. 2008-03-23 02:03:06 +00:00
Jeff Roberson
b7edba7704 - Add a new td flag TDF_NEEDSUSPCHK that is set whenever a thread needs
to enter thread_suspend_check().
 - Set TDF_ASTPENDING along with TDF_NEEDSUSPCHK so we can move the
   thread_suspend_check() to ast() rather than userret().
 - Check TDF_NEEDSUSPCHK in the sleepq_catch_signals() optimization so
   that we don't miss a suspend request.  If this is set use the
   expensive signal path.
 - Set NEEDSUSPCHK when creating a new thread in thr in case the
   creating thread is due to be suspended as well but has not yet.

Reviewed by:	davidxu (Authored original patch)
2008-03-21 08:23:25 +00:00
Jeff Roberson
374ae2a393 - Relax requirements for p_numthreads, p_threads, p_swtick, and p_nice from
requiring the per-process spinlock to only requiring the process lock.
 - Reflect these changes in the proc.h documentation and consumers throughout
   the kernel.  This is a substantial reduction in locking cost for these
   fields and was made possible by recent changes to threading support.
2008-03-19 06:19:01 +00:00
Julian Elischer
c67ddc21e7 This time REALLY copy the name from the proc to the thread as a default. 2007-11-15 06:35:26 +00:00
Konstantin Belousov
89b57fcf01 Fix for the panic("vm_thread_new: kstack allocation failed") and
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
2007-11-05 11:36:16 +00:00
David Xu
0b1f0611b4 Add thr_kill2 syscall which sends a signal to a thread in another process.
Submitted by: Tijl Coosemans tijl at ulyssis dot org
Approved by: re (kensmith)
2007-08-16 05:26:42 +00:00
John Baldwin
a66fde8d35 - Remove unused variable from create_thread().
- Move kern_thr_*() prototype to <sys/syscallsubr.h> where all the other
  kern_*() prototypes live.
2007-06-07 19:45:19 +00:00
Jeff Roberson
982d11f836 Commit 14/14 of sched_lock decomposition.
- 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)
2007-06-05 00:00:57 +00:00
Jeff Roberson
f0393f063a - Remove setrunqueue and replace it with direct calls to sched_add().
setrunqueue() was mostly empty.  The few asserts and thread state
   setting were moved to the individual schedulers.  sched_add() was
   chosen to displace it for naming consistency reasons.
 - Remove adjustrunqueue, it was 4 lines of code that was ifdef'd to be
   different on all three schedulers where it was only called in one place
   each.
 - Remove the long ifdef'd out remrunqueue code.
 - Remove the now redundant ts_state.  Inspect the thread state directly.
 - Don't set TSF_* flags from kern_switch.c, we were only doing this to
   support a feature in one scheduler.
 - Change sched_choose() to return a thread rather than a td_sched.  Also,
   rely on the schedulers to return the idlethread.  This simplifies the
   logic in choosethread().  Aside from the run queue links kern_switch.c
   mostly does not care about the contents of td_sched.

Discussed with:	julian

 - Move the idle thread loop into the per scheduler area.  ULE wants to
   do something different from the other schedulers.

Suggested by:	jhb

Tested on:	x86/amd64 sched_{4BSD, ULE, CORE}.
2007-01-23 08:46:51 +00:00
Julian Elischer
ad1e7d285a Threading cleanup.. part 2 of several.
Make part of John Birrell's KSE patch permanent..
Specifically, remove:
Any reference of the ksegrp structure. This feature was
never fully utilised and made things overly complicated.
All code in the scheduler that tried to make threaded programs
fair to unthreaded programs.  Libpthread processes will already
do this to some extent and libthr processes already disable it.

Also:
Since this makes such a big change to the scheduler(s), take the opportunity
to rename some structures and elements that had to be moved anyhow.
This makes the code a lot more readable.

The ULE scheduler compiles again but I have no idea if it works.

The 4bsd scheduler still reqires a little cleaning and some functions that now do
ALMOST nothing will go away, but I thought I'd do that as a separate commit.

Tested by David Xu, and Dan Eischen using libthr and libpthread.
2006-12-06 06:34:57 +00:00
David Xu
745fbd3a72 if a thread blocked on userland condition variable is
pthread_cancel()ed, it is expected that the thread will not
consume a pthread_cond_signal(), therefor, we use thr_wake()
to mark a flag, the flag tells a thread calling do_cv_wait()
in umtx code to not block on a condition variable.
Thread library is expected that once a thread detected itself
is in pthread_cond_wait, it will call the thr_wake() for itself
in its SIGCANCEL handler.
2006-12-04 14:15:12 +00:00
Tom Rhodes
c4f7f0fd4a Update includes for sys/posix4 move.
Approved by:	silence on -arch and -standards
2006-11-11 16:46:31 +00:00
Robert Watson
acd3428b7d Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges.  These may
require some future tweaking.

Sponsored by:           nCircle Network Security, Inc.
Obtained from:          TrustedBSD Project
Discussed on:           arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
                        Alex Lyashkov <umka at sevcity dot net>,
                        Skip Ford <skip dot ford at verizon dot net>,
                        Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:42:10 +00:00
John Birrell
8460a577a4 Make KSE a kernel option, turned on by default in all GENERIC
kernel configs except sun4v (which doesn't process signals properly
with KSE).

Reviewed by:	davidxu@
2006-10-26 21:42:22 +00:00
David Xu
cda9a0d1c2 Add compatible code to let 32bit libthr work on 64bit kernel. 2006-09-22 15:04:28 +00:00
David Xu
73fa3e5b88 Replace system call thr_getscheduler, thr_setscheduler, thr_setschedparam
with rtprio_thread, while rtprio system call is for process only, the new
system call rtprio_thread is responsible for LWP.
2006-09-21 04:18:46 +00:00
David Xu
fd4a6d10a4 Same as previous change, the user provided priority should be reversed
too.
2006-08-25 10:05:30 +00:00
David Xu
de08f4ee5c POSIX requires that higher numerical values for the priority represent
higher priorities, so we should reverse the passed value here.
2006-08-23 07:22:25 +00:00
David Xu
60088160c9 Add syscalls thr_setscheduler, thr_getscheduler, and thr_setschedparam,
these syscalls are designed to set thread's scheduling parameters and
policy, because each syscall contains a size parameter, it is possible
to support future scheduling option, e.g SCHED_SPORADIC, this option
needs other fields in structure sched_param, current they are not
avaiblable.
2006-07-13 06:26:43 +00:00
David Xu
a94d3e1f8a Use newkg to check if SCHED_OTHER is already inherited. 2006-07-12 07:02:28 +00:00
David Xu
2dca4ca723 Don't forget to check invalid policy! 2006-07-11 08:19:57 +00:00
David Xu
2f26f4c66c For SCHED_OTHER, we always inherit current thread's interactive priority
unless current thread is realtime thread, in such case, we set a new zero
priority for it, notice we don't have per-thread nice, the priority
passed by userland is ignored here.
2006-07-11 06:01:14 +00:00
David Xu
a0712c99d0 Add POSIX scheduler parameters support to thr_new syscall, this permits
privileged process to create realtime thread.
2006-07-11 05:34:35 +00:00
David Xu
adc9c950af Create thread in separated ksegrp, so they always get correct user level
priority.
2006-07-10 23:14:07 +00:00
John Baldwin
0f180a7cce Change msleep() and tsleep() to not alter the calling thread's priority
if the specified priority is zero.  This avoids a race where the calling
thread could read a snapshot of it's current priority, then a different
thread could change the first thread's priority, then the original thread
would call sched_prio() inside msleep() undoing the change made by the
second thread.  I used a priority of zero as no thread that calls msleep()
or tsleep() should be specifying a priority of zero anyway.

The various places that passed 'curthread->td_priority' or some variant
as the priority now pass 0.
2006-04-17 18:20:38 +00:00
David Xu
71b7afb2b4 Call thread_stopped in thr_exit to notify parent that the child process
is now fully stopped, this was already in kse_exit().
2006-02-10 03:34:29 +00:00
David Xu
9e7d72246f Implement thr_set_name to set a name for thread.
Reviewed by: julian
2006-02-05 02:18:46 +00:00
David Xu
0a5cd498bb Add a new feature to thr_kill, if thread ID argument is -1, send
signals to all threads except current sender.
2006-01-07 03:15:21 +00:00
David Xu
6d7b314b14 Cleanup some signal interfaces. Now the tdsignal function accepts
both proc pointer and thread pointer, if thread pointer is NULL,
tdsignal automatically finds a thread, otherwise it sends signal
to given thread.
Add utility function psignal_event to send a realtime sigevent
to a process according to the delivery requirement specified in
struct sigevent.
2005-11-03 04:49:16 +00:00
David Xu
d1f16b4d2e Oops, don't change tdsignal call. 2005-11-03 01:38:49 +00:00
David Xu
44355392b4 Add thread_find() function to search a thread by lwpid. 2005-11-03 01:34:08 +00:00
David Xu
4938faa635 do umtx_wake at userland thread exit address, so that others userland
threads can wait for a thread to exit, and safely assume that the thread
has left userland and is no longer using its userland stack, this is
necessary for pthread_join when a thread is waiting for another thread
to exit which has user customized stack, after pthread_join returns,
the userland stack can be reused for other purposes, without this change,
the joiner thread has to spin at the address to ensure the thread is really
exited.
2005-10-26 06:55:46 +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
David Xu
740fd64d65 Validate if the value written into {FS,GS}.base is a canonical
address, writting non-canonical address can cause kernel a panic,
by restricting base values to 0..VM_MAXUSER_ADDRESS, ensuring
only canonical values get written to the registers.

Reviewed by: peter, Josepha Koshy < joseph.koshy at gmail dot com >
Approved by: re (scottl)
2005-07-10 23:31:11 +00:00
David Xu
c4bd610f58 Add new syscall thr_new to create thread in atomic, it will
inherit signal mask from parent thread, setup TLS and stack, and
user entry address.
Also support POSIX thread's PTHREAD_SCOPE_PROCESS and PTHREAD_SCOPE_SYSTEM,
sysctl is also provided to control the scheduler scope.
2005-04-23 02:36:07 +00:00
Warner Losh
9454b2d864 /* -> /*- for copyright notices, minor format tweaks as necessary 2005-01-06 23:35:40 +00:00
David Xu
c1df5a1a5d If a thread is resumed by thr_wake, it should return 0, especially it
should not return ERESTART after it caught a signal, otherwise
thr_wake() call will be lost, also a timeout wait should not be
restarted. Final, using wakeup not wakeup_one to be safeness.
2004-12-01 13:50:04 +00:00
David Schultz
6db36923ad Remove local definitions of RANGEOF() and use __rangeof() instead.
Also remove a few bogus casts.
2004-11-20 23:00:59 +00:00
Mike Makonnen
401901ac43 Close a race between a thread exiting and the freeing of it's stack.
After some discussion the best option seems to be to signal the thread's
death from within the kernel. This requires that thr_exit() take an
argument.

Discussed with: davidxu, deischen, marcel
MFC after: 3 days
2004-10-06 14:23:00 +00:00
David Xu
195f5806e4 Close a race between thr_create and sysctl -w, the thr_scope_sys could
be changed when thr_create is running, and we tested it for several times.
2004-10-06 02:29:19 +00:00
Julian Elischer
246409821c fix typo
MFC after:	2 days
2004-09-07 07:04:47 +00:00
Julian Elischer
a8b491c121 Give libthr a choice (per system) of scope_system or scope_thread
scheduling.

MFC after:	4 days
2004-09-07 06:33:39 +00:00
Julian Elischer
ed062c8d66 Refactor a bunch of scheduler code to give basically the same behaviour
but with slightly cleaned up interfaces.

The KSE structure has become the same as the "per thread scheduler
private data" structure. In order to not make the diffs too great
one is #defined as the other at this time.

The KSE (or td_sched) structure is  now allocated per thread and has no
allocation code of its own.

Concurrency for a KSEGRP is now kept track of via a simple pair of counters
rather than using KSE structures as tokens.

Since the KSE structure is different in each scheduler, kern_switch.c
is now included at the end of each scheduler. Nothing outside the
scheduler knows the contents of the KSE (aka td_sched) structure.

The fields in the ksegrp structure that are to do with the scheduler's
queueing mechanisms are now moved to the kg_sched structure.
(per ksegrp scheduler private data structure). In other words how the
scheduler queues and keeps track of threads is no-one's business except
the scheduler's. This should allow people to write experimental
schedulers with completely different internal structuring.

A scheduler call sched_set_concurrency(kg, N) has been added that
notifies teh scheduler that no more than N threads from that ksegrp
should be allowed to be on concurrently scheduled. This is also
used to enforce 'fainess' at this time so that a ksegrp with
10000 threads can not swamp a the run queue and force out a process
with 1 thread, since the current code will not set the concurrency above
NCPU, and both schedulers will not allow more than that many
onto the system run queue at a time. Each scheduler should eventualy develop
their own methods to do this now that they are effectively separated.

Rejig libthr's kernel interface to follow the same code paths as
linkse for scope system threads. This has slightly hurt libthr's performance
but I will work to recover as much of it as I can.

Thread exit code has been cleaned up greatly.
exit and exec code now transitions a process back to
'standard non-threaded mode' before taking the next step.
Reviewed by:	scottl, peter
MFC after:	1 week
2004-09-05 02:09:54 +00:00