Commit Graph

173 Commits

Author SHA1 Message Date
Marcel Moolenaar
fdcac92868 Assign thread IDs to kernel threads. The purpose of the thread ID (tid)
is twofold:
1. When a 1:1 or M:N threaded process dumps core, we need to put the
   register state of each of its kernel threads in the core file.
   This can only be done by differentiating the pid field in the
   respective note. For this we need the tid.
2. When thread support is present for remote debugging the kernel
   with gdb(1), threads need to be identified by an integer due to
   limitations in the remote protocol. This requires having a tid.

To minimize the impact of having thread IDs, threads that are created
as part of a fork (i.e. the initial thread in a process) will inherit
the process ID (i.e. tid=pid). Subsequent threads will have IDs larger
than PID_MAX to avoid interference with the pid allocation algorithm.
The assignment of tids is handled by thread_new_tid().

The thread ID allocation algorithm has been written with 3 assumptions
in mind:
1. IDs need to be created as fast a possible,
2. Reuse of IDs may happen instantaneously,
3. Someone else will write a better algorithm.
2004-04-03 15:59:13 +00:00
Julian Elischer
84eef27df4 Massively up the (artificial) limit on system scope threads
in a process from 50 to 500

Also up the number of process scope threads allowed to be in the kernel
at one time from 150 to 1500 (per process)
2004-03-21 09:22:38 +00:00
Peter Wemm
37814395c1 Push Giant down a little further:
- no longer serialize on Giant for thread_single*() and family in fork,
  exit and exec
- thread_wait() is mpsafe, assert no Giant
- reduce scope of Giant in exit to not cover thread_wait and just do
  vm_waitproc().
- assert that thread_single() family are not called with Giant
- remove the DROP/PICKUP_GIANT macros from thread_single() family
- assert that thread_suspend_check() s not called with Giant
- remove manual drop_giant hack in thread_suspend_check since we know it
  isn't held.
- remove the DROP/PICKUP_GIANT macros from thread_suspend_check() family
- mark kse_create() mpsafe
2004-03-13 22:31:39 +00:00
John Baldwin
707559e402 Check for TDF_SINTR before calling sleepq_abort() as there is a narrow
race in between sleepq_add() and sleepq_catch_signals() in that setting
td_wchan and TDF_SINTR is not atomic to sched_lock but only to the sleepq
lock.  This band-aid will stop assertion failures, but there is perhaps a
larger problem with the sleepq_add/sleepq_catch_signals race that I am not
sure how to solve.  For the signals case the race is harmless because we
always call cursig() after setting TDF_SINTR.  However, KSE doesn't do
anything in sleepq_catch_signals() to check that this race was lost, so I
am unsure if this race is harmful for this specific abort.
2004-03-01 23:07:58 +00:00
John Baldwin
44f3b09204 Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
  and condition variables.  Having sleep qeueus in a hash table avoids
  having to allocate a queue head for each wait channel.  Thus, struct cv
  has shrunk down to just a single char * pointer now.  However, the
  hash table does not hold threads directly, but queue heads.  This means
  that once you have located a queue in the hash bucket, you no longer have
  to walk the rest of the hash chain looking for threads.  Instead, you have
  a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
  differentiates between cv's and sleep/wakeup.  For example, calls to
  abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
  Thus, the TDF_CVWAITQ flag is removed.  Also, calls to unsleep() and
  cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
  sleep's no longer inherently bump the priority.  Instead, this is soley
  a propery of msleep() which explicitly calls sched_prio() before
  blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used.  The
  associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
  dropped and replaced with a single explicit clearing of td_wchan.
  TD_SET_ONSLEEPQ() would really have only made sense if it had taken
  the wait channel and message as arguments anyway.  Now that that only
  happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
John Baldwin
62a0fd943c Use mtx_assert() rather than using a home-rolled version. 2004-01-28 20:26:39 +00:00
Jeff Roberson
29bcc4514f - Add a flags parameter to mi_switch. The value of flags may be SW_VOL or
SW_INVOL.  Assert that one of these is set in mi_switch() and propery
   adjust the rusage statistics.  This is to simplify the large number of
   users of this interface which were previously all required to adjust the
   proper counter prior to calling mi_switch().  This also facilitates more
   switch and locking optimizations.
 - Change all callers of mi_switch() to pass the appropriate paramter and
   remove direct references to the process statistics.
2004-01-25 03:54:52 +00:00
Robert Watson
679365e7b9 Reduce gratuitous includes: don't include jail.h if it's not needed.
Presumably, at some point, you had to include jail.h if you included
proc.h, but that is no longer required.

Result of:	self injury involving adding something to struct prison
2004-01-21 17:10:47 +00:00
Jens Schweikhardt
85495c72ff s/Muliple/Multiple
Removed whitespace at EOL and EOF.
2004-01-10 18:34:01 +00:00
Peter Wemm
55cdddc0d8 Don't use NULL (pointer) when we mean 0 (integer) for the number of ticks
in msleep.
2003-12-23 02:28:42 +00:00
Marcel Moolenaar
ccb46feb8e Write the thread pointer (val) in the kse mailbox (loc) before we
set the new context in kse_switchin(2). This allows us to return
an error to the calling context when the suword() fails.
2003-12-10 01:59:23 +00:00
Marcel Moolenaar
702b2a179c Add kse_switchin(2). This syscall can be used by KSE implementations
to have the kernel switch to a new thread, instead of doing it in
userland. It is in fact needed on ia64 where syscall restarts do not
return to userland first. It's completely handled inside the kernel.
As such, any context created by the kernel as part of an upcall and
caused by some syscall needs to be restored by the kernel.
2003-12-07 19:34:29 +00:00
Alan Cox
bca62663ab - Giant is no longer required by vm_thread_new(). 2003-12-07 04:16:49 +00:00
John Baldwin
961a7b244d Add an implementation of turnstiles and change the sleep mutex code to use
turnstiles to implement blocking isntead of implementing a thread queue
directly.  These turnstiles are somewhat similar to those used in Solaris 7
as described in Solaris Internals but are also different.

Turnstiles do not come out of a fixed-sized pool.  Rather, each thread is
assigned a turnstile when it is created that it frees when it is destroyed.
When a thread blocks on a lock, it donates its turnstile to that lock to
serve as queue of blocked threads.  The queue associated with a given lock
is found by a lookup in a simple hash table.  The turnstile itself is
protected by a lock associated with its entry in the hash table.  This
means that sched_lock is no longer needed to contest on a mutex.  Instead,
sched_lock is only used when manipulating run queues or thread priorities.
Turnstiles also implement priority propagation inherently.

Currently turnstiles only support mutexes.  Eventually, however, turnstiles
may grow two queue's to support a non-sleepable reader/writer lock
implementation.  For more details, see the comments in sys/turnstile.h and
kern/subr_turnstile.c.

The two primary advantages from the turnstile code include: 1) the size
of struct mutex shrinks by four pointers as it no longer stores the
thread queue linkages directly, and 2) less contention on sched_lock in
SMP systems including the ability for multiple CPUs to contend on different
locks simultaneously (not that this last detail is necessarily that much of
a big win).  Note that 1) means that this commit is a kernel ABI breaker,
so don't mix old modules with a new kernel and vice versa.

Tested on:	i386 SMP, sparc64 SMP, alpha SMP
2003-11-11 22:07:29 +00:00
David Xu
ab2baa7254 Let SA process work under ULE scheduler, originally it would panic kernel.
Reviewed by: jeff
2003-08-26 11:33:15 +00:00
Sam Leffler
c06eb4e293 Change instances of callout_init that specify MPSAFE behaviour to
use CALLOUT_MPSAFE instead of "1" for the second parameter.  This
does not change the behaviour; it just makes the intent more clear.
2003-08-19 17:51:11 +00:00
Peter Grehan
eac100658a Update powerpc to use the (old thread,new thread) calling convention
for cpu_throw() and cpu_switch().
2003-08-14 03:56:24 +00:00
John Baldwin
e9911cf591 - Convert Alpha over to the new calling conventions for cpu_throw() and
cpu_switch() where both the old and new threads are passed in as
  arguments.  Only powerpc uses the old conventions now.
- Update comments in the Alpha swtch.s to reflect KSE changes.

Tested by:	obrien, marcel
2003-08-12 19:33:36 +00:00
Daniel Eischen
ab908f5935 Copyin the thread mailbox flags from the correct location
in the mailbox.
2003-08-08 20:23:10 +00:00
John Baldwin
8b149b5131 Consistently use the BSD u_int and u_short instead of the SYSV uint and
ushort.  In most of these files, there was a mixture of both styles and
this change just makes them self-consistent.

Requested by:	bde (kern_ktrace.c)
2003-08-07 15:04:27 +00:00
David Xu
d3b5e418bc Introduce a thread mailbox flag TMF_NOUPCALL. On some architectures other
than i386 or AMD64, TP register points to thread mailbox, and they can not
atomically clear km_curthread in kse mailbox, in this case, thread retrieves
its thread pointer from TP register and sets flag TMF_NOUPCALL in its thread
mailbox to indicate a critical region.
2003-08-05 12:00:55 +00:00
John Baldwin
139b7550d9 Set td_critnest to 1 when setting up a thread since it is a MI field with
MI values.  This ensures that td_critnest for a newly fork'd thread is
always valid.

Requested by:	bde (a long time ago)
2003-08-04 20:28:20 +00:00
David Xu
dd7da9aa28 o Refine kse_thr_interrupt to allow it to handle different commands.
o Remove TDF_NOSIGPOST.
o Add a member td_waitset to proc structure, it will be used for sigwait.

Tested by: deischen
2003-07-17 22:45:33 +00:00
David Xu
af161f2232 If initial thread is still a bound thread, don't change its signal mask. 2003-07-15 14:04:38 +00:00
David Xu
4b7d5d84ee Rename thread_siginfo to cpu_thread_siginfo 2003-07-15 04:26:26 +00:00
Mike Makonnen
8689793bfb kse_thr_interrupt should target the thread, specifically.
Requested by:	davidxu
2003-07-04 01:41:32 +00:00
Mike Makonnen
c197abc49a Signals sent specifically to a particular thread must
be delivered to that thread, regardless of whether it
has it masked or not.

Previously, if the targeted thread had the signal masked,
it would be put on the processes' siglist. If
another thread has the signal umasked or unmasks it before
the target, then the thread it was intended for would never
receive it.

This patch attempts to solve the problem by requiring callers
of tdsignal() to say whether the signal is for the thread or
for the process. If it is for the process, then normal processing
occurs and any thread that has it unmasked can receive it.
But if it is destined for a specific thread, it is put on
that thread's pending list regardless of whether it is currently
masked or not.

The new behaviour still needs more work, though.  If the signal
is reposted for some reason it is always posted back to the
thread that handled it because the information regarding the
target of the signal has been lost by then.

Reviewed by:	jdp, jeff, bde (style)
2003-07-03 19:09:59 +00:00
David Xu
df9c6cda37 Fix typo. 2003-06-30 10:04:04 +00:00
Marcel Moolenaar
4e4422d4d4 Don't use fuword() and suword() on struct members of type int. This
happens to work on 32-bit platforms as sizeof(long)=sizeof(int), but
wrecks all kinds of havoc (garbage reads, corrupting writes and
misaligned loads/stores) on 64-bit architectures.
The fix for now is to use fuword32() and suword32() and change the
type of the applicable int fields to int32. This is to make it
explicit that we depend on these fields being 32-bit. We may want
to revisit this later.

Reviewed by: deischen
2003-06-28 19:45:15 +00:00
David Xu
9dde3bc999 o Change kse_thr_interrupt to allow send a signal to a specified thread,
or unblock a thread in kernel, and allow UTS to specify whether syscall
  should be restarted.
o Add ability for UTS to monitor signal comes in and removed from process,
  the flag PS_SIGEVENT is used to indicate the events.
o Add a KMF_WAITSIGEVENT for KSE mailbox flag, UTS call kse_release with
  this flag set to wait for above signal event.
o For SA based thread, kernel masks all signal in its signal mask, let
  UTS to use kse_thr_interrupt interrupt a thread, and install a signal
  frame in userland for the thread.
o Add a tm_syncsig in thread mailbox, when a hardware trap occurs,
  it is used to deliver synchronous signal to userland, and upcall
  is schedule, so UTS can process the synchronous signal for the thread.

Reviewed by: julian (mentor)
2003-06-28 08:29:05 +00:00
David Xu
ab78d4d641 cpu_set_upcall_kse needs to access userspace, release schedule lock
before calling it for bound thread. To avoid this problem, change
thread_schedule_upcall to not put new thread on run queue, let caller
do it, so we can tweak the new thread before setting it to run.

Reported by: pho
2003-06-20 09:12:12 +00:00
David Xu
4184d79115 Forgot to commit code to disable creating a bound thread in same
group again except first kse_create syscall.

Noticed by: julian
2003-06-16 23:46:41 +00:00
David Xu
075102cc4e Reset ncpus to 1 for bound thread group since there is only one
thread in such group.
Change message text from kse_rel to kserel, it is better displayed
in top.
2003-06-16 13:14:52 +00:00
David Xu
cd4f6ebb13 1. Add code to support bound thread. when blocked, a bound thread never
schedules an upcall. Signal delivering to a bound thread is same as
   non-threaded process. This is intended to be used by libpthread to
   implement PTHREAD_SCOPE_SYSTEM thread.
2. Simplify kse_release() a bit, remove sleep loop.
2003-06-15 12:51:26 +00:00
David Xu
1d5a24bec6 1. Migrate TDF_UPCALLING from td_flags to td_pflags.
2. Add a flag TDF_SA, it will be used to distinguish SA
   based thread from bound thread.
2003-06-15 03:18:58 +00:00
David Xu
0e2a4d3aeb Rename P_THREADED to P_SA. P_SA means a process is using scheduler
activations.
2003-06-15 00:31:24 +00:00
Alan Cox
49a2507bd1 Migrate the thread stack management functions from the machine-dependent
to the machine-independent parts of the VM.  At the same time, this
introduces vm object locking for the non-i386 platforms.

Two details:

1. KSTACK_GUARD has been removed in favor of KSTACK_GUARD_PAGES.  The
different machine-dependent implementations used various combinations
of KSTACK_GUARD and KSTACK_GUARD_PAGES.  To disable guard page, set
KSTACK_GUARD_PAGES to 0.

2. Remove the (unnecessary) clearing of PG_ZERO in vm_thread_new.  In
5.x, (but not 4.x,) PG_ZERO can only be set if VM_ALLOC_ZERO is passed
to vm_page_alloc() or vm_page_grab().
2003-06-14 23:23:55 +00:00
David Xu
7677ce18b8 Fix error in my last commit. Correctly maintain p_maxthrwaits and unlock
sched_lock.
2003-06-11 01:08:33 +00:00
David E. O'Brien
677b542ea2 Use __FBSDID(). 2003-06-11 00:56:59 +00:00
David Xu
36407bec4f If there are signals delivered to current thread, breaks out of loop,
userret() will be called again by ast() and thread_userret() will be
called again by userret().

Reported by: tegge
2003-06-10 02:21:32 +00:00
David Xu
b0bd5f38a6 thread_signal_add now is called with ps_mtx held, unlock it before
calling copyin.
2003-06-06 02:17:38 +00:00
Marcel Moolenaar
11e0f8e16d Change the second (and last) argument of cpu_set_upcall(). Previously
we were passing in a void* representing the PCB of the parent thread.
Now we pass a pointer to the parent thread itself.
The prime reason for this change is to allow cpu_set_upcall() to copy
(parts of) the trapframe instead of having it done in MI code in each
caller of cpu_set_upcall(). Copying the trapframe cannot always be
done with a simply bcopy() or may not always be optimal that way. On
ia64 specifically the trapframe contains information that is specific
to an entry into the kernel and can only be used by the corresponding
exit from the kernel. A trapframe copied verbatim from another frame
is in most cases useless without some additional normalization.

Note that this change removes the assignment to td->td_frame in some
implementations of cpu_set_upcall(). The assignment is redundant.
A previous call to cpu_thread_setup() already did the exact same
assignment. An added benefit of removing the redundant assignment is
that we can now change td_pcb without nasty side-effects.

This change officially marks the ability on ia64 for 1:1 threading.

Not tested on: amd64, powerpc
Compile & boot tested on: alpha, sparc64
Functionally tested on: i386, ia64
2003-06-04 21:13:21 +00:00
Julian Elischer
2b035cbe5a Remove un-needed code.
Don't copyin() data we are about to overwrite.
Add a flag to tell userland that KSE is officially "DONE" with the
mailbox and has gone away.

Obtained from:	davidxu@
2003-06-04 00:12:57 +00:00
Marcel Moolenaar
bf822712f7 Remove the ia64 hackery in threadinit() that was needed to work around
the lameness of the kstack code. The EPC overhaul de-lame-ified the
kstack code by removing the need for contigmalloc(). We can now
allocate stacks using malloc(). We probably want to make the stacks
swappable as well so that we can make it MI. But that's another story.
2003-06-01 05:57:58 +00:00
Poul-Henning Kamp
670966596b Remove unused variable(s).
Found by:       FlexeLint
2003-05-31 20:29:34 +00:00
Marcel Moolenaar
f2c49dd248 Revamp of the syscall path, exception and context handling. The
prime objectives are:
o  Implement a syscall path based on the epc inststruction (see
   sys/ia64/ia64/syscall.s).
o  Revisit the places were we need to save and restore registers
   and define those contexts in terms of the register sets (see
   sys/ia64/include/_regset.h).

Secundairy objectives:
o  Remove the requirement to use contigmalloc for kernel stacks.
o  Better handling of the high FP registers for SMP systems.
o  Switch to the new cpu_switch() and cpu_throw() semantics.
o  Add a good unwinder to reconstruct contexts for the rare
   cases we need to (see sys/contrib/ia64/libuwx)

Many files are affected by this change. Functionally it boils
down to:
o  The EPC syscall doesn't preserve registers it does not need
   to preserve and places the arguments differently on the stack.
   This affects libc and truss.
o  The address of the kernel page directory (kptdir) had to
   be unstaticized for use by the nested TLB fault handler.
   The name has been changed to ia64_kptdir to avoid conflicts.
   The renaming affects libkvm.
o  The trapframe only contains the special registers and the
   scratch registers. For syscalls using the EPC syscall path
   no scratch registers are saved. This affects all places where
   the trapframe is accessed. Most notably the unaligned access
   handler, the signal delivery code and the debugger.
o  Context switching only partly saves the special registers
   and the preserved registers. This affects cpu_switch() and
   triggered the move to the new semantics, which additionally
   affects cpu_throw().
o  The high FP registers are either in the PCB or on some
   CPU. context switching for them is done lazily. This affects
   trap().
o  The mcontext has room for all registers, but not all of them
   have to be defined in all cases. This mostly affects signal
   delivery code now. The *context syscalls are as of yet still
   unimplemented.

Many details went into the removal of the requirement to use
contigmalloc for kernel stacks. The details are mostly CPU
specific and limited to exception_save() and exception_restore().
The few places where we create, destroy or switch stacks were
mostly simplified by not having to construct physical addresses
and additionally saving the virtual addresses for later use.

Besides more efficient context saving and restoring, which of
course yields a noticable speedup, this also fixes the dreaded
SMP bootup problem as a side-effect. The details of which are
still not fully understood.

This change includes all the necessary backward compatibility
code to have it handle older userland binaries that use the
break instruction for syscalls. Support for break-based syscalls
has been pessimized in favor of a clean implementation. Due to
the overall better performance of the kernel, this will still
be notived as an improvement if it's noticed at all.

Approved by: re@ (jhb)
2003-05-16 21:26:42 +00:00
David Xu
c6523b663f Fix compiling problem, p_tracee is in my local repository for
threaded process debugging, not ready for this time.
2003-05-01 12:16:06 +00:00
David Xu
1ecc645634 Drop Giant lock before suspended, pick up it after resumed.
thread_suspend_check() is used in exit1() which still needs
Giant lock.
2003-05-01 07:29:25 +00:00
Peter Wemm
cb1f265c60 AMD64 uses the new-style cpu_switch()/cpu_throw() calling conventions. 2003-04-30 21:45:03 +00:00
David Xu
5c29a450ae Increase some default values. 2003-04-30 01:18:29 +00:00