option DDB_NO_LCALLS to stop ddb getting control and broke all ddb
tracing. Now there is no option and no way for ddb to trace at
address _Xsyscall or to _Xsyscall, but tracing everywhere else
works. The previous fix did unnecessary things for Linux syscalls.
Don't bother checking that syscall frames are for user mode.
Make debugger traps inside the kernel (except at addresses _Xsyscall
and _Xsyscall+1) fatal if ddb is not configured. They "can't happen".
Add prototypes.
Remove stupid comments, e.g., /*ARGSUSED*/ for args that are used.
match the board setting.
2) Fixed the warning message to properly print the irq mismatch (as opposed
to the bit encoded value).
3) Add irq autodetection if the kernel has "?" or no irq specified.
4) Add missing splimp protection in ixioctl().
Obtained from: other people on the net ?
1. stepping over syscalls (gdb ni) sends you to DDB, and returned
to the wrong address afterwards, with or without DDB. patch in
i386/i386/trap.c below.
2. the linux emulator (modload'ed) still causes panics with DIAGNOSTIC,
re-applied a patch posted to one of the lists...
This is really just a token gesture at this point. We can't really turn
on swapping here anymore because (I think) we need to do a namei() lookup
in order to get a vnode which we can pass to swaponvp(). But to do a
namei(), we need a properly initialized proc structure, and we don't
have one. (I was hopping to toss it proc0, but that isn't initialized
until later.) We could conceiveably fabricate a dummy proc structure
to make namei() happy, but that's too much work for too little payoff.
For now, swapgeneric's only remaining saving grace is that it lets
you set the root device with -a.
1542 revs work by assuming the next few sequential ID codes are
new Adaptec boards and enabling them after printing a warning.
Conditionalize the informational boot messages with "if (bootverbose)".
were making and were no-brainers. However, the xcdplayer
eject button didn't work because xcdplayer gave up and didn't bother
to try the EJECT ioctl anyway when CDIOCALLOW was not available.
This all works now.
o A change so that xcdplayer gets TOC entry data for the lead-out area
on the disc. Xcdplayer can now play the last track on a CD, which
it would not do in earlier versions (but no one reported).
Cdplayer gets the TOC data differently and it works in old and new
versions.
o Eliminated a race condition that caused the driver to sleep forever
on very slow and heavily loaded systems on rare occasions when
the system was doing lots of audio-related ioctls to the drive.
o Fixed a problem where a locked drive could be unlocked by accessing
one of the non-locking devs. Door locking now follows the documented
rules.
o Made all wait channel strings unique to matcd.
Submitted by: Frank Durda IV <uhclem%nemesis@fw.ast.com>
scheduled for demolition. This is a first step: get rid of if_zereg.h,
by adding the five extra definitions to if_edreg.h.
Also add some definitions which will become needed when if_ze.c gets
replaced entirely by pccard and if_ed.c. (this is a 2.1.0 candidate)
with the driver's stability now. I've not had a single problem with it for
weeks.. All that remains is a bit of performance tuning, and finishing
the manpages.
Now comes up in the old line-oriented interface by default for serial
and pcvt folk with a `visual' command for going to the visual interface.
Best of both worlds, no?
Submitted by: Michael Smith <msmith@atrad.adelaide.edu.au>
Changes relative to 1.12:
- Put extra instruction between outl()/inl() sequence to prevent the
old value being read back because of the bus capacitance.
- Additional check for existence of register at CONF2_ENABLE_PORT.
setting the control register. Make the read and write operations two
completely separate steps.
While we're at it, pull in the whole set of Cyrix cache control options
from NetBSD-current, since a few motherboards do the right thing with
the Cyrix chip.
There is no option to disable the internal cache completely (yet).
Reviewed by: pst
Obtained from: NetBSD
ignore and set it to 18 sectors/track. This allows FreeBSD to boot with
2.88MB floppies which are used in older ThinkPads.
Submitted by: Random Net person whose name I lost
EFAULT if it is not resident. This prevents the system from manufacturing
a zero-fill page for unused but allocated areas of the kernel's VM. This
should fix the "CMAP busy" panic that some people saw during system
startup.
there is a PCI bus at all) ...
- Do not expect the chip sets to follow even very clearly expressed
requirements of the PCI 2.0 spec.
- Do not read back the value just written to an I/O port without making
sure that some other data have crossed the bus in between ...
2) Killed i386pagesperpage as it is not used by anything.
3) Fixed benign miscalculations in pmap_bootstrap().
4) Moved allocation of ISA DMA memory to machdep.c.
5) Removed bogus vm_map_find()'s in pmap_init() - the entire range was
already allocated kmem_init().
6) Added some comments.
virual_avail is still miscalculated NKPT*NBPG too large, but in order to
fix this properly requires moving the variable initialization into locore.s.
Some other day.
used and went a long way toward confusing the code.
2) Fix proc0's initial stack to not be 48 bytes smaller than it needs to
be.
3) Correct comment about 'first' arg to init386().
Add prototypes. Use static for function definitions to match existing
prototypes. Otherwise leave functions that should be static as extern.
TODO: declare everthing except sidriver and siintr as static. I use
some new cdevs registration functions to do this for syscons and pcvt.
Fix siintr() to match its prototype in ioconf.c (don't return anything).
This may break the eisa support, but Julian says that eisa interrupts
never worked anyway.
(EISA support was never tested anyway - Peter)
Submitted by: bde
the first one in the config has priority. They can be switched using
userconfig().
i386/i386/conf.c:
Initialize the shared syscons/pcvt cdevsw entry to `nx'.
Add cdevsw registration functions.
Use devsw functions of the correct type if they exist.
i386/i386/cons.c:
Add renamed syscons entry points to constab.
i386/i386/cons.h:
Declare the renamed syscons entry points.
i386/i386/machdep.c:
Repeat console initialization after userconfig() in case the current
console has become wrong. This depends on cn functions not wiring down
anything important.
sys/conf.h:
Declare new functions.
i386/isa/isa.[ch]:
Add a function to decide which display driver has priority. Should be
done better.
i386/isa/syscons.c:
Rename pccn* -> sccn*.
Initialize CRTC start address in case the previous driver has moved it.
i386/isa/syscons.c, i386/isa/pcvt/*
Initialize the bogusly shared variable Crtat dynamically in case the
stored value was changed by the previous driver.
Initialize cdevsw table from a template.
Don't grab the console if another display driver has priority.
i386/isa/syscons.h, i386/isa/pcvt/pcvt_hdr.h:
Don't externally declare now-static cdevsw functions.
i386/isa/pcvt/pcvt_hdr.h:
Set the sensitive hardware flag so that pcvt doesn't always have lower
priority than syscons. This also fixes the "stupid" detection of the
display after filling the display with text.
i386/isa/pcvt/pcvt_out.c:
Don't be confused the off-screen cursor offset 0xffff set by syscons.
kern/subr_xxx.c:
Add enough nxio/nodev/null devsw functions of the correct type for syscons
and pcvt.
Split off cdevsw initialization in cninit() into a new function
cninit_finish() that isn't called until all hardware device drivers
have been attached. The bdevsw entry of the driver for the physical
console needs to be hooked after the physical driver has been
attached in case the attachment modified the entry.
Rearrange cninit() to avoid changing cn_tab until the driver for the
physical console has been initialized, so that the previous driver
(if any) can be used for debugging.
Start removing half-baked lint support. bdevsw functions usually have
unused args but /*ARGSUSED*/ was used for only about 5% of them.
cons.h:
Declare cn_init_finish().
autoconf.c:
Call cn_init_finish().
Start adding prototypes. Functions with bogus linkage (extern where
static is probably should be static) are explicitly declared as extern
so that the can be found easily (extern in a non-header is usually
wrong).
All:
Continue cleaning up init stuff: init functions shall be static;
INITs should be at the start of files...
by me...
Original message:
This patch upgrades the ATAPI CD-ROM driver to version 1.3.
It has three bugs fixed:
1) The `controller not ready' message at startup and later.
It was caused by staled media change bit.
2) Incorrect shuffling of model string for some drives (NEC, Mitsumi).
3) Handling of drives which report itself as been of direct-access type,
instead of CD-ROM type.
There is one known bug which is not fixed yet -- probing
in absense of IDE disks. A work-around exists though (thanks Steve!).
If you have no IDE disks attached, then remove them from the kernel
config file to make the CD-ROM attach correctly.
Unfortunately, there is no way to disable them from the kernel
interactive config mode.
Reviewed by: sos (Soren Schmidt)
Submitted by: vak@gw.cronyx.msk.su (Serge V.Vakulenko)
2) Output K bytes instead of pages as this means something to more people.
3) Moved printf of avail memory to after vm_bounce_init() call so that
bounce buffers are included in the figure.
4) Killed initcpu(); it's an unused vestige from the VAX.
1) Make the driver "quiet" by sticking most boot messages behind
bootverbose conditionals. This means that you won't see the
sync and wide negotiation, but you will find out if they fail.
2) Add support to the 93cx6 serial eeprom code to read at an abitrary
offset. This is needed so that we can access the second half
of the eeprom on 3940 cards where the second channel's config
is stored.
3) Add flags argument to ahcprobe(). This is used by the pci probe code
to tell the generic driver that an adapter should be treated
as a channel B device as well as notify it of the presence of
external SCB SRAM. These are needed for some motherboard
implementations of the aic7870 and for the 3940 controllers.
4) Print "Channel A"/"Channel B" instead of "Single Channel" for the
two busses of the 3940. I received many reports of confusion
about how the 3940 was probed since most people belived that
only one ahc entry was needed. This will hopefully make it
clearer.
5) Walk the SCBs to determine just how many their are if external SCB
ram is detected.
6) Hard code that external SCB ram is present for the 3940 since it doesn't
use the documented reporting facility for reporting the SRAM. :(
255 commands per channel are supported on the 3940.
7) Read the seeprom starting at addres 32 for the second channel of the
3940 so we get the right info for that channel.
8) Clean up printing of the "Disabling tagged queuing message".
9) Queue timeouts if they occur while we are handling a timeout. The code
was totally unprotected in this scenario.
Reviewed by: Timeout code reviewed by David Greenman <davidg>
/*
+ * Code for MTERASE added by John Lind (john@starfire.mn.org) 95/09/02.
+ * This was very easy due to the excellent structure and clear coding
+ * of the original driver.
+ */
changes to allow devices that don't probe (e.g. /dev/mem)
to create devfs entries
this required giving 'configure' its own SYSINIT entry
so we could duck in just before it with a DEVFS init
and some device inits..
my devfs now looks like:
./misc
./misc/speaker
./misc/mem
./misc/kmem
./misc/null
./misc/zero
./misc/io
./misc/console
./misc/pcaudio
./misc/pcaudioctl
./disks
./disks/rfloppy
./disks/rfloppy/fd0.1440
./disks/rfloppy/fd1.1200
./disks/floppy
./disks/floppy/fd0.1440
./disks/floppy/fd1.1200
also some sligt cleanups.. DEVFS needs a lot of work
but I'm getting back to it..
had a 2.1 tag, thus sending these two changes into the 2.1 branch instead
of -current. Argh. I may bring these changes into the 2.1 anyway (they're
benign there) so I'm not going to admin them out of 2.1 for the time
being.
Submitted by: terry (terry lambert)
This is a composite of 3 patch sets submitted by terry.
they are:
New low-level init code that supports loadbal modules better
some cleanups in the namei code to help terry in 16-bit character support
some changes to the mount-root code to make it a little more
modular..
NOTE: mounting root off cdrom or NFS MIGHT be broken as I haven't been able
to test those cases..
certainly mounting root of disk still works just fine..
mfs should work but is untested. (tomorrows task)
The low level init stuff includes a total rewrite of init_main.c
to make it possible for new modules to have an init phase by simply
adding an entry to a TEXT_SET (or is it DATA_SET) list. thus a new module can
be added to the kernel without editing any other files other than the
'files' file.
calls with a byte size of 1. This special case was not
correctly emulated. Now programs such as a simple 'ls' to a commercial
Macintosh emulator called 'executor' will work correctly.
This is still very green, but I have managed to get my modem working.
Lots of work still to do, but now at least we can commit it. /phk
Reviewed by: phk
Submitted by: Andrew McRae <andrew@mega.com.au>
This change forces the controller drivers to allocate a scsibus_data struct
via a call to scsi_alloc_bus(), fill in the adapter_link field, and optionally
modify any other fields of the struct. Scsi_alloc_bus() initializes all fields
to the default, so the changes in most drivers are very minimal. For drivers
that support Wide controllers, the maxtarg field will have to be updated to
allow probing of all targets (for an example, look at the aic7xxx driver).
Scsi_attachdevs() now takes a scsibus_data* as its argument instead of an
sc_link*. This allows us to expand the role of the scsibus_data struct for
other bus level configuration setings (max number of transactions, current
transaction opennings, etc for better tagged queuing support).
Reviewed by: Rodney Grimes <rgrimes>, Peter Dufault <dufault>, Julian Elischer <julian>
Change some leading spaces to tabs.
This change forces the controller drivers to allocate a scsibus_data struct
via a call to scsi_alloc_bus(), fill in the adapter_link field, and optionally
modify any other fields of the struct. Scsi_alloc_bus() initializes all fields
to the default, so the changes in most drivers are very minimal. For drivers
that support Wide controllers, the maxtarg field will have to be updated to
allow probing of all targets (for an example, look at the aic7xxx driver).
Scsi_attachdevs() now takes a scsibus_data* as its argument instead of an
sc_link*. This allows us to expand the role of the scsibus_data struct for
other bus level configuration setings (max number of transactions, current
transaction opennings, etc for better tagged queuing support).
Reviewed by: Rodney Grimes <rgrimes>, Peter Dufault <dufault>, Julian Elischer <julian>
Implement the slip/ppp "hotchar" detection to improve latency
Debug the L_RINT bypass code..
Fix an interesting feature that caused 8-bit chars to loose their top bit
in some circumstances..
This finishes the remaining outstanding problems that I'm aware of, with
the exception of efficiency... Optimizing can come later after it's fully
debugged.
Claim the major numbers (before sombedoy else jumps in again and
claims the slots for his foocd driver :-), install all the hooks that
are required.
While i've been at this, i've cleaned up some of the routines at the
end of i386/conf.c; all the importers of the latest CDROM drivers
forgot to fill in the appropriate information. The `ata' driver
(vapourware?) does only occupy a slot in the bdevsw[] array, btw.
The actual import of the code does require a minor change in the SCSI
subsystem, and i want to have this reviewed by Peter first, so it will
be deferred for some days. The driver is already working for me
though.
Submitted by: akiyama@kme.mei.co.jp (Shunsuke Akiyama)
Note, I tested this on a NEC Versa, IBM 750C, and a IBM 755CX w/out
problems. The card still works fine in TP mode.
Submitted by: schwarz@alpharel.com (Steve Schwarz)
Reviewed by: jleppek@suw2k.ess.harris.com (James Leppek)
actually a timeout only. The existing behaviour caused a
mcd0: timeout getreply
at halt/reboot time.
Submitted by: graichen@sirius.physik.fu-berlin.de (Thomas Graichen)
traps occurred. This also helps ddb backtrace through trap frames.
Backtracing through syscall and interrupt frames still doesn't work
but it is relatively unimportant and more expensive to fix.
moved to the driver proper, so that <machine/si.h> can be #included by user
programs without needing to include stuff from /sys/i386/isa..
Various (now) redundant features removed, eg: the locks on IXANY and HWFLOW
as these are now done with the "initial" and "lock" termios devices.
Note that it still (for reasons unknown) appears to be masking data to
7-bit with ppp - hence the cleanup to support the debugging via 'sicontrol'
This was originally ported to BSDI by Andy Rutter <andy@acronym.co.uk>.
At the end of the day, this code has very little in common with Andy's
version, or the Specialix SYSV version. Essentially it has been gradually
and almost completely rewritten, with LOTS of advice and inspiration from
Bruce Evans. There are a couple of missing bits still, but they are minor.
The user-mode "sicontrol" program is in sad shape and will come in soon.
Transparent printing died a timely death.. Maybe later..
Jeremy Rolls @ Specialix (Development directory) has confirmed this is OK
to distribute, and Andy personally sent me his version that I started from.
Although this driver stood up to a nasty stress-test in this form, I am not
confident that there are no nasty bugs lurking.
People are welcome to try it, but dont go out and buy one just yet.. :-)
And *DONT* use it on a mission-critical machine... This is ALPHA QUALITY!
of "__volatile". Note also that the original mods that were submitted
by me were as a result of a discussion between various FreeBSD contributors.
Submitted by: peter@haywire.dialix.com (Peter Wemm)
for return values. It just so happens that in the cases where it is likely
to fail, it is okay to change the M_NOWAIT to M_WAITOK -- and all will
be well. This problem was manfest as a panic very regularly on a 4MB
system right after bootup.
hardware. Set the sleep-on flag for the address so there is more
than a small chance that the sleep address is actually used (this
used to work by timing out). Don't bother clearing the sleep-on
flag after a timeout here or elsewhere since leaving it set just
generates a few null calls to wakeup().
Introduce TS_CONNECTED and TS_ZOMBIE states. TS_CONNECTED is set
while a connection is established. It is set while (TS_CARR_ON or
CLOCAL is set) and TS_ZOMBIE is clear. TS_ZOMBIE is set for on to
off transitions of TS_CARR_ON that occur when CLOCAL is clear and
is cleared for off to on transitions of CLOCAL. I/o can only occur
while TS_CONNECTED is set. TS_ZOMBIE prevents further i/o.
Split the input-event sleep address TSA_CARR_ON(tp) into TSA_CARR_ON(tp)
and TSA_HUP_OR_INPUT(tp). The former address is now used only for
off to on carrier transitions and equivalent CLOCAL transitions.
The latter is used for all input events, all carrier transitions
and certain CLOCAL transitions. There are some harmless extra
wakeups for rare connection- related events. Previously there were
too many extra wakeups for non-rare input events.
Drivers now call l_modem() instead of setting TS_CARR_ON directly
to handle even the initial off to on transition of carrier. They
should always have done this. l_modem() now handles TS_CONNECTED
and TS_ZOMBIE as well as TS_CARR_ON.
gnu/isdn/iitty.c:
Set TS_CONNECTED for first open ourself to go with bogusly setting
CLOCAL.
i386/isa/syscons.c, i386/isa/pcvt/pcvt_drv.c:
We fake carrier, so don't also fake CLOCAL.
kern/tty.c:
Testing TS_CONNECTED instead of TS_CARR_ON fixes TIOCCONS forgetting to
test CLOCAL. TS_ISOPEN was tested instead, but that broke when we disabled
the clearing of TS_ISOPEN for certain transitions of CLOCAL.
Testing TS_CONNECTED fixes ttyselect() returning false success for output
to devices in state !TS_CARR_ON && !CLOCAL.
Optimize the other selwakeup() call (this is not related to the other
changes).
kern/tty_pty.c:
ptcopen() can be declared in traditional C now that dev_t isn't short.
Use input buffer watermarks of TTYHOG-512 (high) and (high)*7/8
(low) instead of TTYHOG/2 (high) and TTYHOG/5 (low) to agree with
some drivers. 512 is magic and some things depended on TTYHOG/2
>= TTYHOG-512 to work; now they depend on the 512 magic not changing
and TTYHOG-512 being significantly larger than 0. This should be
handled in ttsetwater().
Separate the decision about whether to do input flow control from
doing it. ttyblock() now just starts input flow control (hardware
and/or software) and there is a new function ttyunblock() to stop
it. The decisions are the same except for the watermark changes
and allowing for input expansion for PARMRK.
When flushing input, try harder at first to send a start character
if required, but give up if the first attempt fails.
cy.c, rc.c, sio.c:
Simplify: let ttyinput() handle input flow control if it is not
being bypassed. Use ttyblock() to start flow control otherwise.
rc.c:
Use same input flow control test as elsewhere: test in a more
efficient order and start flow control at >= highwater instead of
at > highwater.
BUS DEVICE RESET followed by BUS RESET failure recovery strategy including
the necesary renegotiation of sync/wide transfers after recovery completes.
Clean up debugging code to make it more finely selectable. Reset code
debugging is enabled for now so I can get more feedback on how this
code behaves in real life.
essential when I fix excessive wakeups for output-below-low-water.
In cy.c and sio.c, wake up via the driver start routine to also
eliminate duplicated code involving the clearing of TS_TTSTOP.
Always (except in code to be replaced soon) call driver start
routine directly instead of going through ttstart().
Amancio. There is some SoundSource support here that is primitive and
probably doesn't work, but I'll let the two submitters let me know
how my integration of that was since I don't have this card to test.
I've only tested this on my GUS MAX since it's all I have.
This all probably needs to be re-done anyway since we're widely variant
from the original VOXWARE source in the current layout.
Submitted by: Amancio Hasty and Jim Lowe
Obtained from: Hannu Savolainen
floppy DMA buffers...use avail_start not "first". Removed duplicate
(and wrong) declaration of phys_avail[].
Submitted by: Bruce Evans, but fixed differently by me.
This finishes making the kernel compile without -O.
The "optimized" asm version of the function being inlined
(translate_bytes()) uses slow instructions. On a 486, assuming
everything is in the cache (unlikely), it is 21/15 times slower
than the dumb C version and 21/3 times slower than the best
possible bytewise method.
didn't work are somewhat bogusly optimized away before the constraint
is checked. We still expect constants passed to inline functions to
remain constant, but if the compiler ever decides that they aren't
constant then it will just generate slightly slower code instead of
an error.
Declare `cheat' as static. It was bogusly shared between the aha1742 and
ultrastor drivers.
Even static variables should have unique names so that they can be
debugged, but fixing them can wait.
ttwwakeup(). The conditions for doing the wakeup will soon become
more complicated and I don't want them duplicated in all drivers.
It's probably not worth making ttwwakeup() a macro or an inline
function. The cost of the function call is relatively small when
there is a process to wake up. There is usually a process to wake
up for large writes and the system call overhead dwarfs the function
call overhead for small writes.
Temporarily nuke TS_WOPEN. It was only used for the obscure MDMBUF
flow control option in the kernel and for informational purposes
in `pstat -t'. The latter worked properly only for ptys. In
general there may be multiple processes sleeping in open() and
multiple processes that successfully opened the tty by opening it
in O_NONBLOCK mode or during a window when CLOCAL was set. tty.c
doesn't have enough information to maintain the flag but always
cleared it in ttyopen().
TS_WOPEN should be restored someday just so that `pstat -t' can
display it (MDMBUF is already fixed). Fixing it requires counting
of processes sleeping in open() in too many serial drivers.
buses on multi-bus controllers. Currently only affects the 274xT controllers.
Reviewed by: Peter Dufault(dufault@hda.com), Rod Grimes(rgrimes@FreeBSD.org)
emul code when compiling with "options KTRACE".
ktrsyscall() was expecting an array of integers, this was passing the
address of a structure containing an array of integers..
The cosmetic problem was that it was calling the "enter syscall"
trace hook twice - this looks like a cut/paste error/typo.
Submitted by: Andrew McRae <andrew@mega.com.au>
Some initial commits from the pcmcia stuff, to make life easier for the
testers.
We will use the name "pccard" since that is really the buzzword at present.
notebooks where a powerfail condition (external power drop; battery
state low) is signalled by an NMI. Makes it beep instead of panicing.
Reviewed by: davidg
Future Domain TMC-885 controllers. These beasts were just different enough in
a number of perverse ways to be recognised but not work with the seagate
stuff. I also whacked in blind transfers for DATAIN and DATAOUT phases - this
more than doubles my throughput. If you're dubious about that, comment out the
definition of SEA_BLINDTRANSFER. Anyway if you're running an ST01 or TMC-950
controller, please give this a go, I'd like to see if anything's broken for
those beasts.
Submitted by: Stephen Hocking <sysseh@devetir.qld.gov.au>
proc or any VM system structure will have to be rebuilt!!!
Much needed overhaul of the VM system. Included in this first round of
changes:
1) Improved pager interfaces: init, alloc, dealloc, getpages, putpages,
haspage, and sync operations are supported. The haspage interface now
provides information about clusterability. All pager routines now take
struct vm_object's instead of "pagers".
2) Improved data structures. In the previous paradigm, there is constant
confusion caused by pagers being both a data structure ("allocate a
pager") and a collection of routines. The idea of a pager structure has
escentially been eliminated. Objects now have types, and this type is
used to index the appropriate pager. In most cases, items in the pager
structure were duplicated in the object data structure and thus were
unnecessary. In the few cases that remained, a un_pager structure union
was created in the object to contain these items.
3) Because of the cleanup of #1 & #2, a lot of unnecessary layering can now
be removed. For instance, vm_object_enter(), vm_object_lookup(),
vm_object_remove(), and the associated object hash list were some of the
things that were removed.
4) simple_lock's removed. Discussion with several people reveals that the
SMP locking primitives used in the VM system aren't likely the mechanism
that we'll be adopting. Even if it were, the locking that was in the code
was very inadequate and would have to be mostly re-done anyway. The
locking in a uni-processor kernel was a no-op but went a long way toward
making the code difficult to read and debug.
5) Places that attempted to kludge-up the fact that we don't have kernel
thread support have been fixed to reflect the reality that we are really
dealing with processes, not threads. The VM system didn't have complete
thread support, so the comments and mis-named routines were just wrong.
We now use tsleep and wakeup directly in the lock routines, for instance.
6) Where appropriate, the pagers have been improved, especially in the
pager_alloc routines. Most of the pager_allocs have been rewritten and
are now faster and easier to maintain.
7) The pagedaemon pageout clustering algorithm has been rewritten and
now tries harder to output an even number of pages before and after
the requested page. This is sort of the reverse of the ideal pagein
algorithm and should provide better overall performance.
8) Unnecessary (incorrect) casts to caddr_t in calls to tsleep & wakeup
have been removed. Some other unnecessary casts have also been removed.
9) Some almost useless debugging code removed.
10) Terminology of shadow objects vs. backing objects straightened out.
The fact that the vm_object data structure escentially had this
backwards really confused things. The use of "shadow" and "backing
object" throughout the code is now internally consistent and correct
in the Mach terminology.
11) Several minor bug fixes, including one in the vm daemon that caused
0 RSS objects to not get purged as intended.
12) A "default pager" has now been created which cleans up the transition
of objects to the "swap" type. The previous checks throughout the code
for swp->pg_data != NULL were really ugly. This change also provides
the rudiments for future backing of "anonymous" memory by something
other than the swap pager (via the vnode pager, for example), and it
allows the decision about which of these pagers to use to be made
dynamically (although will need some additional decision code to do
this, of course).
13) (dyson) MAP_COPY has been deprecated and the corresponding "copy
object" code has been removed. MAP_COPY was undocumented and non-
standard. It was furthermore broken in several ways which caused its
behavior to degrade to MAP_PRIVATE. Binaries that use MAP_COPY will
continue to work correctly, but via the slightly different semantics
of MAP_PRIVATE.
14) (dyson) Sharing maps have been removed. It's marginal usefulness in a
threads design can be worked around in other ways. Both #12 and #13
were done to simplify the code and improve readability and maintain-
ability. (As were most all of these changes)
TODO:
1) Rewrite most of the vnode pager to use VOP_GETPAGES/PUTPAGES. Doing
this will reduce the vnode pager to a mere fraction of its current size.
2) Rewrite vm_fault and the swap/vnode pagers to use the clustering
information provided by the new haspage pager interface. This will
substantially reduce the overhead by eliminating a large number of
VOP_BMAP() calls. The VOP_BMAP() filesystem interface should be
improved to provide both a "behind" and "ahead" indication of
contiguousness.
3) Implement the extended features of pager_haspage in swap_pager_haspage().
It currently just says 0 pages ahead/behind.
4) Re-implement the swap device (swstrategy) in a more elegant way, perhaps
via a much more general mechanism that could also be used for disk
striping of regular filesystems.
5) Do something to improve the architecture of vm_object_collapse(). The
fact that it makes calls into the swap pager and knows too much about
how the swap pager operates really bothers me. It also doesn't allow
for collapsing of non-swap pager objects ("unnamed" objects backed by
other pagers).
were two races:
- q_to_b() might unexpectedly return 0 (e.g, after a keyboard signal
flushes the output queue and isn't echoed). ansi_put() interprets
0 bytes as 4GB...
- more output (e.g. for echoes) might arrive afer q_to_b() returns 0.
Then scstart() returns presumably and the new output might not be
handled for a long time.
Remove unused function scxint().
Fix prototypes (foo() isn't a prototype).
syscons' output is now only about 4-5 times slower than I want.
It loses a factor of 2 for scrolling output by unnecessarily copying
the screen buffer, a factor of 4/3 for dumb OPOST processing, and
a factor of 3/2 for clist processing.
