Commit Graph

65 Commits

Author SHA1 Message Date
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
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
John Baldwin
d25168e14e Fix two nits in the ps header that offset each other making them largely
unnoticable.
2006-08-01 22:30:55 +00:00
John Baldwin
8b6d68671b Some cosmetic tweaks:
- Right justify 'pid' label.
- Move the uid column to the right 2 columns so that the 3 process id
  columns (pid, ppid, pgrp) are grouped together.
- Expand the uid column to 5 chars.
- Don't indent the tid for multithreaded processes.

Requested by:	bde (1, 2, 4)
2006-08-01 15:29:46 +00:00
John Baldwin
19e9205a23 Simplify the pager support in DDB. Allowing different db commands to
install custom pager functions didn't actually happen in practice (they
all just used the simple pager and passed in a local quit pointer).  So,
just hardcode the simple pager as the only pager and make it set a global
db_pager_quit flag that db commands can check when the user hits 'q' (or a
suitable variant) at the pager prompt.  Also, now that it's easy to do so,
enable paging by default for all ddb commands.  Any command that wishes to
honor the quit flag can do so by checking db_pager_quit.  Note that the
pager can also be effectively disabled by setting $lines to 0.

Other fixes:
- 'show idt' on i386 and pc98 now actually checks the quit flag and
  terminates early.
- 'show intr' now actually checks the quit flag and terminates early.
2006-07-12 21:22:44 +00:00
John Baldwin
10fd453475 Use __LP64__ rather than the PTR64 hack.
Suggested by:	ru
2006-05-11 21:59:55 +00:00
John Baldwin
a421d57149 Sort includes. 2006-04-27 22:09:18 +00:00
John Baldwin
eefcd2a1e6 A whitespace fix.
Submitted by:	bde
2006-04-27 22:02:27 +00:00
John Baldwin
60b0d00999 Drop locking comments. ddb functions should never use locking anyway and
no other ddb functions try to annotate what locking would otherwise be
appropriate in comments.

Prodded by:	bde
2006-04-27 21:59:43 +00:00
John Baldwin
c9a08d1cad - Overhaul the 'ps' command in ddb to be mostly readable again. :) It is
now back to using fixed-size columns for output and each line of output
  should fit in 80 columns on both 32-bit and 64-bit architectures.  In
  general the output is close to that of the userland ps(1) with the
  exception that the 'wmesg' field is mostly similar to the "state" field
  in top(1) in that it will show either a wmesg, a lock name (prefixed with
  an *), "CPU xx" (for a running thread), or nothing if none of those three
  conditions are true.  It also respects td_name when listing threads in
  a multithreaded process.  There is a somewhat evilly-defined PTR64 macro
  I use to make account for the change in the size of the 'wchan' column
  in the formatted output (wchan is now the only pointer in the ps output
  and is available so it can be passed to 'show sleepq', 'show turnstile',
  or 'show lock').
- Add two new commands "show proc [process]" and "show thread [thread]"
  that show details about the specified process or thread (specified
  either by pid/tid or pointer), respectively.  If an address it not
  specified, it uses the current kdb thread.
2006-04-25 20:34:04 +00:00
David Schultz
626ff2081f Remove the uarea column from the DDB 'ps' display, and from grog's gdb
scripts.

Reviewed by:	arch@
2004-11-20 02:32:42 +00:00
John Baldwin
d39d4a6e64 - Change the ddb paging "support" to use a variable (db_lines_per_page) to
control the number of lines per page rather than a constant.  The variable
  can be examined and changed in ddb as '$lines'.  Setting the variable to
  0 will effectively turn off paging.
- Change db_putchar() to force out pending whitespace before outputting
  newlines and carriage returns so that one can rub out content on the
  current line via '\r     \r' type strings.
- Change the simple pager to rub out the --More-- prompt explicitly when
  the routine exits.
- Add some aliases to the simple pager to make it more compatible with
  more(1): 'e' and 'j' do a single line.  'd' does half a page, and
  'f' does a full page.

MFC after:	1 month
Inspired by:	kris
2004-11-01 22:15:15 +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
Marcel Moolenaar
37224cd3fc Mega update for the KDB framework: turn DDB into a KDB backend.
Most of the changes are a direct result of adding thread awareness.
Typically, DDB_REGS is gone. All registers are taken from the
trapframe and backtraces use the PCB based contexts. DDB_REGS was
defined to be a trapframe on all platforms anyway.
Thread awareness introduces the following new commands:
	thread X	switch to thread X (where X is the TID),
	show threads	list all threads.

The backtrace code has been made more flexible so that one can
create backtraces for any thread by giving the thread ID as an
argument to trace.

With this change, ia64 has support for breakpoints.
2004-07-10 23:47:20 +00:00
Warner Losh
f36cfd49ad Remove advertising clause from University of California Regent's
license, per letter dated July 22, 1999 and email from Peter Wemm,
Alan Cox and Robert Watson.

Approved by: core, peter, alc, rwatson
2004-04-07 20:46:16 +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
Poul-Henning Kamp
71b797c176 Label the uarea address as such in DDB's ps output 2003-08-30 19:06:57 +00:00
John Baldwin
3f2a1b0656 Update the 'ps', 'show pci', and 'show ktr' ddb commands to use the new
pager callout instead of homerolling their own paging facility.
2003-07-31 17:29:42 +00:00
John Baldwin
cb075651f8 Whitespace nit. 2003-07-30 20:59:36 +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
David E. O'Brien
753960f7c4 Use __FBSDID(). 2003-06-10 22:09:23 +00:00
Julian Elischer
b410626185 Attempt to crunch down the thread state info so that it is more likely to
fit on one line. Account for threads better.

* No need to report that it is on a sleep queue if it is actually sleeping
* "Normal" state is almost ubiquitous.. only report abnormal states.
* increment the #lines count for each separate thread shown in threaded
  programs.

makes it less likely that a threaded program will make all the data
on a screen overflow off the top of the screen.
2003-06-06 20:28:11 +00:00
John Baldwin
a85b6f827b Handle the TDS_INACTIVE state by printing '[INACTIVE]' instead of
panic'ing.  Also, for unknown thread states, print out the value rather
than panic.  Panic'ing in the debugger is pointless at best.
2003-06-06 17:20:47 +00:00
John Baldwin
ac39898e7e Whitespace nits. 2003-06-06 17:19:27 +00:00
Julian Elischer
060563ec50 Move the _oncpu entry from the KSE to the thread.
The entry in the KSE still exists but it's purpose will change a bit
when we add the ability to lock a KSE to a cpu.
2003-04-10 17:35:44 +00:00
Julian Elischer
ac2e415327 Change the process flags P_KSES to be P_THREADED.
This is just a cosmetic change but I've been meaning to do it for about a year.
2003-02-27 02:05:19 +00:00
Jeff Roberson
5215b1872f - Split the struct kse into struct upcall and struct kse. struct kse will
soon be visible only to schedulers.  This greatly simplifies much the
   KSE code.

Submitted by:	davidxu
2003-02-17 05:14:26 +00:00
Julian Elischer
6f8132a867 Reversion of commit by Davidxu plus fixes since applied.
I'm not convinced there is anything major wrong with the patch but
them's the rules..

I am using my "David's mentor" hat to revert this as he's
offline for a while.
2003-02-01 12:17:09 +00:00
David Xu
0dbb100b9b Move UPCALL related data structure out of kse, introduce a new
data structure called kse_upcall to manage UPCALL. All KSE binding
and loaning code are gone.

A thread owns an upcall can collect all completed syscall contexts in
its ksegrp, turn itself into UPCALL mode, and takes those contexts back
to userland. Any thread without upcall structure has to export their
contexts and exit at user boundary.

Any thread running in user mode owns an upcall structure, when it enters
kernel, if the kse mailbox's current thread pointer is not NULL, then
when the thread is blocked in kernel, a new UPCALL thread is created and
the upcall structure is transfered to the new UPCALL thread. if the kse
mailbox's current thread pointer is NULL, then when a thread is blocked
in kernel, no UPCALL thread will be created.

Each upcall always has an owner thread. Userland can remove an upcall by
calling kse_exit, when all upcalls in ksegrp are removed, the group is
atomatically shutdown. An upcall owner thread also exits when process is
in exiting state. when an owner thread exits, the upcall it owns is also
removed.

KSE is a pure scheduler entity. it represents a virtual cpu. when a thread
is running, it always has a KSE associated with it. scheduler is free to
assign a KSE to thread according thread priority, if thread priority is changed,
KSE can be moved from one thread to another.

When a ksegrp is created, there is always N KSEs created in the group. the
N is the number of physical cpu in the current system. This makes it is
possible that even an userland UTS is single CPU safe, threads in kernel still
can execute on different cpu in parallel. Userland calls kse_create to add more
upcall structures into ksegrp to increase concurrent in userland itself, kernel
is not restricted by number of upcalls userland provides.

The code hasn't been tested under SMP by author due to lack of hardware.

Reviewed by: julian
2003-01-26 11:41:35 +00:00
Julian Elischer
93a7aa79d6 Add code to ddb to allow backtracing an arbitrary thread.
(show thread {address})

Remove the IDLE kse state and replace it with a change in
the way threads sahre KSEs. Every KSE now has a thread, which is
considered its "owner" however a KSE may also be lent to other
threads in the same group to allow completion of in-kernel work.
n this case the owner remains the same and the KSE will revert to the
owner when the other work has been completed.

All creations of upcalls etc. is now done from
kse_reassign() which in turn is called from mi_switch or
thread_exit(). This means that special code can be removed from
msleep() and cv_wait().

kse_release() does not leave a KSE with no thread any more but
converts the existing thread into teh KSE's owner, and sets it up
for doing an upcall. It is just inhibitted from being scheduled until
there is some reason to do an upcall.

Remove all trace of the kse_idle queue since it is no-longer needed.
"Idle" KSEs are now on the loanable queue.
2002-12-28 01:23:07 +00:00
Julian Elischer
1dab89f156 Remove the process state PRS_WAIT.
It is never used. I left it there from pre-KSE days as I didn't know
if I'd need it or not but now I know I don't.. It's functionality
is in TDI_IWAIT in the thread.
2002-10-21 22:27:36 +00:00
Julian Elischer
48bfcddd94 Round out the facilty for a 'bound' thread to loan out its KSE
in specific situations. The owner thread must be blocked, and the
borrower can not proceed back to user space with the borrowed KSE.
The borrower will return the KSE on the next context switch where
teh owner wants it back. This removes a lot of possible
race conditions and deadlocks. It is consceivable that the
borrower should inherit the priority of the owner too.
that's another discussion and would be simple to do.

Also, as part of this, the "preallocatd spare thread" is attached to the
thread doing a syscall rather than the KSE. This removes the need to lock
the scheduler when we want to access it, as it's now "at hand".

DDB now shows a lot mor info for threaded proceses though it may need
some optimisation to squeeze it all back into 80 chars again.
(possible JKH project)

Upcalls are now "bound" threads, but "KSE Lending" now means that
other completing syscalls can be completed using that KSE before the upcall
finally makes it back to the UTS. (getting threads OUT OF THE KERNEL is
one of the highest priorities in the KSE system.) The upcall when it happens
will present all the completed syscalls to the KSE for selection.
2002-10-09 02:33:36 +00:00
John Baldwin
551cf4e150 Rename the mutex thread and process states to use a more generic 'LOCK'
name instead.  (e.g., SLOCK instead of SMTX, TD_ON_LOCK() instead of
TD_ON_MUTEX())  Eventually a turnstile abstraction will be added that
will be shared with mutexes and other types of locks.  SLOCK/TDI_LOCK will
be used internally by the turnstile code and will not be specific to
mutexes.  Making the change now ensures that turnstiles can be dropped
in at a later date without affecting the ABI of userland applications.
2002-10-02 20:31:47 +00:00
Julian Elischer
71fad9fdee Completely redo thread states.
Reviewed by:	davidxu@freebsd.org
2002-09-11 08:13:56 +00:00
Bruce Evans
efdfb8fea3 db_ps.c:
Don't attempt to follow null pointers for zombie processes in db_ps().

Style fix: use explicit an comparison with NULL for all null pointer
checks in db_ps() instead of for half of them.

db_interface.c:
Fixed ddb's handling of traps from with ddb on i386's only.

This was mostly fixed in rev.1.27 (by longjmp()'ing back to the top
level) but was completly broken in rev.1.48 (by not unwinding the new
state (mainly db_active) either before or after the longjmp().  This
mostly never worked for other arches, since rev.1.27 has not been ported
and lower level longjmp()'s only handle traps for memory accesses.  All
cases should be handled at a lower level to provided better control and
simplify unwinding of state.

Implementation details: don't pretend to maintain db_active in a nested
way -- ddb cannot be reentered in a nested way.  Use db_active instead
of the db_global_jmpbuf_valid flag and longjmp()'s return value for things
related to reentering ddb.  [re]entering is still not atomic enough.
2002-08-31 04:25:44 +00:00
Poul-Henning Kamp
8ede8cbc50 Realign columns in DDB's ps output. Don't waste more horizontal space than
necessary.
2002-08-13 11:06:54 +00:00
Julian Elischer
e602ba25fd Part 1 of KSE-III
The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)

Reviewed by:	Almost everyone who counts
	(at various times, peter, jhb, matt, alfred, mini, bernd,
	and a cast of thousands)

	NOTE: this is still Beta code, and contains lots of debugging stuff.
	expect slight instability in signals..
2002-06-29 17:26:22 +00:00
John Baldwin
5a882ddd66 Commented out locking that would be used in the ps command if locks were
used in ddb.
2002-04-11 21:01:34 +00:00
Julian Elischer
079b7badea Pre-KSE/M3 commit.
this is a low-functionality change that changes the kernel to access the main
thread of a process via the linked list of threads rather than
assuming that it is embedded in the process. It IS still embeded there
but remove all teh code that assumes that in preparation for the next commit
which will actually move it out.

Reviewed by: peter@freebsd.org, gallatin@cs.duke.edu, benno rice,
2002-02-07 20:58:47 +00:00
John Baldwin
c516499ad4 Make the flag field in the ps output one char wider to account for recent
growth in the number of flags used.  Also, if a thread is blocked on a
mutex, print the mutex name in the wait channel column.
2001-10-20 03:22:23 +00:00
John Baldwin
14b418e7e9 - Whitespace fixes.
- Fix an old bug: p_comm is an array not a pointer, so it can't be NULL.`
2001-09-12 22:32:03 +00:00
Julian Elischer
b40ce4165d KSE Milestone 2
Note ALL MODULES MUST BE RECOMPILED
make the kernel aware that there are smaller units of scheduling than the
process. (but only allow one thread per process at this time).
This is functionally equivalent to teh previousl -current except
that there is a thread associated with each process.

Sorry john! (your next MFC will be a doosie!)

Reviewed by: peter@freebsd.org, dillon@freebsd.org

X-MFC after:    ha ha ha ha
2001-09-12 08:38:13 +00:00
Robert Watson
b1fc0ec1a7 o Merge contents of struct pcred into struct ucred. Specifically, add the
real uid, saved uid, real gid, and saved gid to ucred, as well as the
  pcred->pc_uidinfo, which was associated with the real uid, only rename
  it to cr_ruidinfo so as not to conflict with cr_uidinfo, which
  corresponds to the effective uid.
o Remove p_cred from struct proc; add p_ucred to struct proc, replacing
  original macro that pointed.
  p->p_ucred to p->p_cred->pc_ucred.
o Universally update code so that it makes use of ucred instead of pcred,
  p->p_ucred instead of p->p_pcred, cr_ruidinfo instead of p_uidinfo,
  cr_{r,sv}{u,g}id instead of p_*, etc.
o Remove pcred0 and its initialization from init_main.c; initialize
  cr_ruidinfo there.
o Restruction many credential modification chunks to always crdup while
  we figure out locking and optimizations; generally speaking, this
  means moving to a structure like this:
        newcred = crdup(oldcred);
        ...
        p->p_ucred = newcred;
        crfree(oldcred);
  It's not race-free, but better than nothing.  There are also races
  in sys_process.c, all inter-process authorization, fork, exec, and
  exit.
o Remove sigio->sio_ruid since sigio->sio_ucred now contains the ruid;
  remove comments indicating that the old arrangement was a problem.
o Restructure exec1() a little to use newcred/oldcred arrangement, and
  use improved uid management primitives.
o Clean up exit1() so as to do less work in credential cleanup due to
  pcred removal.
o Clean up fork1() so as to do less work in credential cleanup and
  allocation.
o Clean up ktrcanset() to take into account changes, and move to using
  suser_xxx() instead of performing a direct uid==0 comparision.
o Improve commenting in various kern_prot.c credential modification
  calls to better document current behavior.  In a couple of places,
  current behavior is a little questionable and we need to check
  POSIX.1 to make sure it's "right".  More commenting work still
  remains to be done.
o Update credential management calls, such as crfree(), to take into
  account new ruidinfo reference.
o Modify or add the following uid and gid helper routines:
      change_euid()
      change_egid()
      change_ruid()
      change_rgid()
      change_svuid()
      change_svgid()
  In each case, the call now acts on a credential not a process, and as
  such no longer requires more complicated process locking/etc.  They
  now assume the caller will do any necessary allocation of an
  exclusive credential reference.  Each is commented to document its
  reference requirements.
o CANSIGIO() is simplified to require only credentials, not processes
  and pcreds.
o Remove lots of (p_pcred==NULL) checks.
o Add an XXX to authorization code in nfs_lock.c, since it's
  questionable, and needs to be considered carefully.
o Simplify posix4 authorization code to require only credentials, not
  processes and pcreds.  Note that this authorization, as well as
  CANSIGIO(), needs to be updated to use the p_cansignal() and
  p_cansched() centralized authorization routines, as they currently
  do not take into account some desirable restrictions that are handled
  by the centralized routines, as well as being inconsistent with other
  similar authorization instances.
o Update libkvm to take these changes into account.

Obtained from:	TrustedBSD Project
Reviewed by:	green, bde, jhb, freebsd-arch, freebsd-audit
2001-05-25 16:59:11 +00:00
John Baldwin
f34fa851e0 Catch up to header include changes:
- <sys/mutex.h> now requires <sys/systm.h>
- <sys/mutex.h> and <sys/sx.h> now require <sys/lock.h>
2001-03-28 09:17:56 +00:00
Poul-Henning Kamp
6214433089 Use macro API for <sys/queue.h> 2000-12-30 22:06:19 +00:00
Peter Wemm
c3aac50f28 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
Poul-Henning Kamp
ce9edcf5b5 Merge the cons.c and cons.h to the best of my ability. alpha may or
may not compile, I can't test it.
1999-08-09 10:35:05 +00:00
Bruce Evans
c3ba51a722 Removed an especially bogus cast. 1999-05-13 13:01:46 +00:00
Matthew Dillon
a1c1e16ada Changes to support -Wall, -Wcast-qual. Had to make physical code changes
in db_lookup() to avoid the *cp = 0 / *cp = ':' combo ( temporary
    nul-terminate-then-restore-original ) on a const char * string.
1999-01-27 19:00:49 +00:00
Bruce Evans
90163a9b33 Fixed db_printf format errors. 1998-07-08 06:43:57 +00:00