Commit Graph

63 Commits

Author SHA1 Message Date
thorpej 1bd7bb28ea Implement wakeup_one(), which wakes up the highest priority process
first in line for the specified identifier.  For use in places where
you don't want a Thundering Herd.

While here, add an optimization to wakeup() suggested by Ross Harvey.
1999-07-26 23:00:58 +00:00
thorpej ea8fb3e04a Turn the proclist lock into a read/write spinlock. Update proclist locking
calls to reflect this.  Also, block statclock rather than softclock during
in the proclist locking functions, to address a problem reported on
current-users by Sean Doran.
1999-07-25 06:30:33 +00:00
thorpej 01a8cffe77 Add a read/write lock to the proclists and PID hash table. Use the
write lock when doing PID allocation, and during the process exit path.
Use a read lock every where else, including within schedcpu() (interrupt
context).  Note that holding the write lock implies blocking schedcpu()
from running (blocks softclock).

PID allocation is now MP-safe.

Note this actually fixes a bug on single processor systems that was probably
extremely difficult to tickle; it was possible that schedcpu() would run
off a bad pointer if the right clock interrupt happened to come in the
middle of a LIST_INSERT_HEAD() or LIST_REMOVE() to/from allproc.
1999-07-22 21:08:30 +00:00
thorpej 2715b812d1 Rework the process exit path, in preparation for making process exit
and PID allocation MP-safe.  A new process state is added: SDEAD.  This
state indicates that a process is dead, but not yet a zombie (has not
yet been processed by the process reaper).

SDEAD processes exist on both the zombproc list (via p_list) and deadproc
(via p_hash; the proc has been removed from the pidhash earlier in the exit
path).  When the reaper deals with a process, it changes the state to
SZOMB, so that wait4 can process it.

Add a P_ZOMBIE() macro, which treats a proc in SZOMB or SDEAD as a zombie,
and update various parts of the kernel to reflect the new state.
1999-07-22 18:13:36 +00:00
mrg 48c12bfeed revert previous. oops. 1999-04-21 02:37:07 +00:00
mrg 58540a2274 properly test the msgsz as "msgsz - len". from PR#7386 1999-04-21 02:31:49 +00:00
mrg d2397ac5f7 completely remove Mach VM support. all that is left is the all the
header files as UVM still uses (most of) these.
1999-03-24 05:50:49 +00:00
ross e47e3c9f45 schedclk() -> schedclock(), for consistency with hardclock(), statclock(), ...
update comments for recent scheduler mods
1999-02-28 18:14:57 +00:00
ross b4a33c4e60 Scheduler bug fixes and reorganization
* fix the ancient nice(1) bug, where nice +20 processes incorrectly
  steal 10 - 20% of the CPU, (or even more depending on load average)
* provide a new schedclk() mechanism at a new clock at schedhz, so high
  platform hz values don't cause nice +0 processes to look like they are
  niced
* change the algorithm slightly, and reorganize the code a lot
* fix percent-CPU calculation bugs, and eliminate some no-op code

=== nice bug === Correctly divide the scheduler queues between niced and
compute-bound processes. The current nice weight of two (sort of, see
`algorithm change' below) neatly divides the USRPRI queues in half; this
should have been used to clip p_estcpu, instead of UCHAR_MAX.  Besides
being the wrong amount, clipping an unsigned char to UCHAR_MAX is a no-op,
and it was done after decay_cpu() which can only _reduce_ the value.  It
has to be kept <= NICE_WEIGHT * PRIO_MAX - PPQ or processes can
scheduler-penalize themselves onto the same queue as nice +20 processes.
(Or even a higher one.)

=== New schedclk() mechansism === Some platforms should be cutting down
stathz before hitting the scheduler, since the scheduler algorithm only
works right in the vicinity of 64 Hz. Rather than prescale hz, then scale
back and forth by 4 every time p_estcpu is touched (each occurance an
abstraction violation), use p_estcpu without scaling and require schedhz
to be generated directly at the right frequency. Use a default stathz (well,
actually, profhz) / 4, so nothing changes unless a platform defines schedhz
and a new clock.  Define these for alpha, where hz==1024, and nice was
totally broke.

=== Algorithm change === The nice value used to be added to the
exponentially-decayed scheduler history value p_estcpu, in _addition_ to
be incorporated directly (with greater wieght) into the priority calculation.
At first glance, it appears to be a pointless increase of 1/8 the nice
effect (pri = p_estcpu/4 + nice*2), but it's actually at least 3x that
because it will ramp up linearly but be decayed only exponentially, thus
converging to an additional .75 nice for a loadaverage of one. I killed
this, it makes the behavior hard to control, almost impossible to analyze,
and the effect (~~nothing at for the first second, then somewhat increased
niceness after three seconds or more, depending on load average) pointless.

=== Other bugs === hz -> profhz in the p_pctcpu = f(p_cpticks) calcuation.
Collect scheduler functionality. Try to put each abstraction in just one
place.
1999-02-23 02:56:03 +00:00
chs 61458d7dfa LOCKDEBUG enhancements for non-MP:
keep a list of locked locks.
use this to print where the lock was locked
when we either go to sleep with a lock held
or try to free a locked lock.
1998-11-04 06:19:55 +00:00
mycroft fb526e055c Substantial signal handling changes:
* Increase the size of sigset_t to accomodate 128 signals -- adding new
  versions of sys_setprocmask(), sys_sigaction(), sys_sigpending() and
  sys_sigsuspend() to handle the changed arguments.
* Abstract the guts of sys_sigaltstack(), sys_setprocmask(), sys_sigaction(),
  sys_sigpending() and sys_sigsuspend() into separate functions, and call them
  from all the emulations rather than hard-coding everything.  (Avoids uses
  the stackgap crap for these system calls.)
* Add a new flag (p_checksig) to indicate that a process may have signals
  pending and userret() needs to do the full (slow) check.
* Eliminate SAS_ALTSTACK; it's exactly the inverse of SS_DISABLE.
* Correct emulation bugs with restoring SS_ONSTACK.
* Make the signal mask in the sigcontext always use the emulated mask format.
* Store signals internally in sigaction structures, rather than maintaining a
  bunch of little sigsets for each SA_* bit.
* Keep track of where we put the signal trampoline, rather than figuring it out
  in *_sendsig().
* Issue a warning when a non-emulated sigaction bit is observed.
* Add missing emulated signals, and a native SIGPWR (currently not used).
* Implement the `not reset when caught' semantics for relevant signals.

Note: Only code touched by the i386 port has been modified.  Other ports and
emulations need to be updated.
1998-09-11 12:50:05 +00:00
jonathan 466e784ee1 defopt DDB. 1998-07-04 22:18:13 +00:00
thorpej 808867c7cf defopt KTRACE 1998-06-25 21:17:15 +00:00
fvdl e5bc90f40c Merge with Lite2 + local changes 1998-03-01 02:20:01 +00:00
kleink 0dc9b5452d Fix variable declarations: register -> register int. 1998-02-12 20:39:41 +00:00
mrg d90485202c - add defopt's for UVM, UVMHIST and PMAP_NEW.
- remove unnecessary UVMHIST_DECL's.
1998-02-10 14:08:44 +00:00
mrg 1a8c7604f4 initial import of the new virtual memory system, UVM, into -current.
UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code.  i provided some help
getting swap and paging working, and other bug fixes/ideas.  chuck
silvers <chuq@chuq.com> also provided some other fixes.

this is the rest of the MI portion changes.

this will be KNF'd shortly.  :-)
1998-02-05 07:59:28 +00:00
mycroft 61a9f1c6a6 GC pageproc and bclnlist. 1997-10-10 08:19:41 +00:00
mycroft 7f35228e7e Make wmesg arguments to various functions const. 1997-10-09 12:49:44 +00:00
gwr 9fa3dabef7 Moved db_show_all_procs() to kern_proc.c 1997-05-07 18:49:10 +00:00
cgd 8a3333b2a9 Fix an inconsistency that came in with Lite: setrq() was renamed to
setrunqueue(), but remrq() was never renamed.  Rename remrq() to
remrunqueue().
1996-11-06 20:19:19 +00:00
cgd 279c087328 reorganize tsleep() so the (cold || panicstr) test is done before the
ktrace context switch checking.  If syncing disks while handling a panic
that occurred while 'curproc' was NULL, the old code would dereference
NULL and die.  The (slight) reorganization was done so that space (one extra
splhigh()), rather than time (one extra comparison), would be wasted.
1996-10-15 23:00:10 +00:00
christos f443b89c92 backout previous kprintf change 1996-10-13 02:32:29 +00:00
christos 60d201973e printf -> kprintf, sprintf -> ksprintf 1996-10-10 22:46:11 +00:00
ws 2da166f660 Fix p_nice vs. NZERO code.
Change NZERO to 20 to always make p_nice positive.
On Christos' suggestion make p_nice explicitly u_char.
1996-10-02 18:04:56 +00:00
explorer 67b1de765f Add compile-time and run-time control over automatic niceing 1996-07-17 21:54:04 +00:00
christos 4ef330b934 remove include of <sys/cpu.h> 1996-04-22 01:38:12 +00:00
christos 0babd67cbc Fix db_printf formats. 1996-03-30 22:23:18 +00:00
christos 09afd77655 More proto fixes 1996-02-09 18:59:18 +00:00
christos 8a5b1b92e2 First pass at prototyping 1996-02-04 02:15:01 +00:00
mycroft d7e904a697 Fix various signal handling bugs:
* If we got a stopping signal while already stopped with the same signal,
the second signal would sometimes (but not always) be ignored.
* Signals delivered by the debugger always pretended to be stopping
signals.
* PT_ATTACH still didn't quite work right.
1995-06-08 23:51:01 +00:00
christos 3d1b06ab09 - new copyargs routine.
- use emul_xxx
- deprecate nsysent; use constant SYS_MAXSYSCALL instead.
- deprecate ep_setup
- call sendsig and setregs indirectly.
1995-04-22 19:42:47 +00:00
mycroft 7439778432 Use %p. 1995-03-19 23:44:44 +00:00
cgd 6ac2bbfc35 be more careful with types, also pull in headers where necessary. 1994-10-30 21:43:03 +00:00
mycroft c996edc7e1 Display emulation type. 1994-08-30 06:22:10 +00:00
mycroft 016425e503 Clean up some debugging code. 1994-08-30 05:37:14 +00:00
mycroft 2f710a54ee Convert process, file, and namei lists and hash tables to use queue.h. 1994-08-30 03:04:28 +00:00
cgd cf92afd66e New RCS ID's, take two. they're more aesthecially pleasant, and use 'NetBSD' 1994-06-29 06:29:24 +00:00
cgd 21a03cca53 mostly-machine-indepedent switch, and changes to match. also, hack init_main 1994-05-18 05:12:10 +00:00
glass 5f0be76f42 missing rcsid 1994-05-14 19:43:02 +00:00
cgd c6abdc2054 setrq -> setrunqueue, sched -> scheduler 1994-05-13 00:50:41 +00:00
cgd 3c56e9ea46 function name changes 1994-05-07 00:57:23 +00:00
mycroft 8f6071b2ce Put some more code in splstatclock(), just to be safe. 1994-05-06 22:02:25 +00:00
mycroft 26ebb5fdde Now setpri() is really toast. 1994-05-05 09:06:10 +00:00
mycroft be856288a8 setpri() is toast. 1994-05-05 09:02:30 +00:00
mycroft a2bf298443 Remove now-bogus casts. 1994-05-05 08:58:07 +00:00
cgd a0a7429482 lots of changes: prototype migration, move lots of variables, definitions,
and structure elements around.  kill some unnecessary type and macro
definitions.  standardize clock handling.  More changes than you'd want.
1994-05-05 05:35:42 +00:00
cgd 4bbabd8e7a Rename a lot of process flags. 1994-05-04 03:41:12 +00:00
cgd e0db92993a change timeout/untimeout/wakeup/sleep/tsleep args to void * 1994-04-29 23:15:51 +00:00
cgd 87dfd3227e cast to match header (changed back...) 1993-12-22 13:46:28 +00:00