Commit Graph

39 Commits

Author SHA1 Message Date
jeff
590a39e29b - 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
e8efa7328e 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
davidxu
4b9b549ca2 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
dde96893c9 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
8aebe48934 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
6b6ba96b60 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
jhb
8c9a393a04 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
5702a380a5 Completely redo thread states.
Reviewed by:	davidxu@freebsd.org
2002-09-11 08:13:56 +00:00
bde
cc37b25dbb 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
phk
6528cc2b4d Realign columns in DDB's ps output. Don't waste more horizontal space than
necessary.
2002-08-13 11:06:54 +00:00
julian
aa2dc0a5d9 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
jhb
7674fba730 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
b5eb64d6f0 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
jhb
8ceded814a 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
jhb
c1c40c6cff - 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
5596676e6c 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
rwatson
f504530d9f 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
jhb
b47bfbe544 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
phk
72cd3208b3 Use macro API for <sys/queue.h> 2000-12-30 22:06:19 +00:00
peter
3b842d34e8 $Id$ -> $FreeBSD$ 1999-08-28 01:08:13 +00:00
phk
ee871b6440 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
bde
1a3527cffb Removed an especially bogus cast. 1999-05-13 13:01:46 +00:00
dillon
153f359f37 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
bde
e4073f6c6f Fixed db_printf format errors. 1998-07-08 06:43:57 +00:00
bde
3ef4a761cf Fixed scrolling. Newline at the "--More--" prompt scrolled 2 lines. 1997-10-09 00:20:00 +00:00
peter
94b6d72794 Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.
1997-02-22 09:48:43 +00:00
jkh
808a36ef65 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00
peter
f420d94a19 A small bit of defensive programming in case the panic is during process
exit and cleanup.  the 'ps' command assumes that there are always 'nproc'
processes on the lists and will walk off the end without checking if not,
causing ddb to trap during the 'ps' command.
1996-06-15 07:08:02 +00:00
hsu
7530dffb8e For Lite2: proc LIST changes.
Reviewed by:	david & bde
1996-03-11 05:55:56 +00:00
bde
0cb993b9a2 Reduced and cleaned up #includes. 1995-12-10 19:08:32 +00:00
dg
c30f46c534 Untangled the vm.h include file spaghetti. 1995-12-07 12:48:31 +00:00
bde
c854b9d5a9 Change db_ps() to have the correct number and type of args for a ddb
command.
1995-08-27 02:40:39 +00:00
dg
0ca978d61c Make db_ps tolerant of uninitialized struct proc fields. Improved 'more'
function to work like you'd expect. Other misc cleanup.
1995-08-20 05:25:11 +00:00
rgrimes
c86f0c7a71 Remove trailing whitespace. 1995-05-30 08:16:23 +00:00
dg
27e6941140 Fixed the formatting breakage I added in the previous commit. 1995-04-04 01:35:33 +00:00
dg
14d50aee6d Fixed DDB's "ps" output formatting. 1995-03-28 23:29:52 +00:00
phk
ad1c6ca62b #include ddb.h not db_output.h 1994-09-28 19:16:24 +00:00
phk
2f56b9ec91 Added include of <machine/cons.h> so that cngetc() gets declared. 1994-09-27 20:35:55 +00:00
dg
991b08fc7a ddb ps function from 1.1.5. Moved into its own file and cleaned up a bit
by me.
1994-08-27 16:28:45 +00:00