set improves performance and fixes the following problems (description
from John Dyson):
1. Growing swap space problem in both static usage and
in situations with lots of fork/execs in heavy paging
situations.
2. Sparse swap space allocation (internal fragmentation.)
3. General swap_pager slowness.
Additionally, the new swap_pager also provides hooks for multi-page
I/O that is currently being developed (in early testing phases.)
Problem #1 is a result of a problem where objects cannot be collapsed
once a pager has been allocated for them. This problem has been solved
by relaxing the restriction by allowing the pages contained in a shadow
object's pager be copied to the parent object's pager. The copy is
afforded by manipulating pointers to the disk blocks on the swap space.
Since an improved swap_pager has already been developed with the data
structures to support the copy operation, this new swap_pager has been
introduced. Also, shadow object bypass in the collapse code has been
enhanced to support checking for pages on disk. The vm_pageout daemon
has also been modified to defer creation of an object's pager when the
object's shadow is paging. This allows efficient immediate collapsing
of a shadow into a parent object under many circumstances without the
creation of an intermediate pager.
Problem #2 is solved by the allocation data structures and algorithms
in the new swap_pager. Additionally, a newer version of this new swap_pager
is being tested that permits multiple page I/O and mitigation of the
fragmentation problems associated with allocation of large contiguous blocks
of swap space.
Problem #3 is addressed by better algorithms and a fix of a couple of bugs
in the swap_pager. Additionally, this new pager has a growth path allowing
multi-page inputs from disk. Approximately 50% performance improvement can
be expected under certain circumstances when using this pager in the standard
single page mode.
(Actually, I've seen more like twice the speed in my tests. -DLG)
are used or not.
Add .verions to the CLEANFILES+= on those Makefiles that create a version.c
file.
Remove reference to nonexistent file ref_omega.c in one Makefile.
Fix copy of authdes.c.expot so that it works with or without obj directories.
No compiles both with and without obj directories.
can actually write a sane netif device to support one of these. Note that it
was necessary to steal a netisr bit from another protocol; I took the one for
PF_DATAKIT (no great loss).
a binary link-kit. Make all non-optional options (pagers, procfs) standard,
and update LINT to reflect new symtab requirements.
NB: -Wtraditional will henceforth be forgotten. This editing pass was
primarily intended to detect any constructions where the old code might
have been relying on traditional C semantics or syntax. These were all
fixed, and the result of fixing some of them means that -Wall is now a
realistic possibility within a few weeks.
Entries for 800 and 820 fixed.
From vak@kiae.su:
incorporate Joerg Wunsch formatting code
correct handle timeouted operations
fixed entry for 720 media
GAP values changed suitable for possible format code addition.
Read/write GAP always 2 now.
Interleave parameter added for possible format code addition.
Many logical formats added.
720K physical drive added.
Problems: still can't read 720..820 media in 1.44 drive.
800K in HD 5.25in (maximum for DD diskettes)
1.44M in HD 5.25in (for easy distributions)
1.46M in HD 5.25in (maximum for 5.25)
Some cosmetique changes.
Now minor looks like UU DDDDDD, UU - unit, DDDDDD - density.
If density == 0, CMOS-detect format assumed.
For old users/pgms use fake partitions now, i.e.
ln fd0 fd0[a-h]
No new floppy names added (expect fd? and rfd?),
because don't have agreement yet, so make devices
only for CMOS-detected formats.
Now minor looks like UU DDDDDD, UU - unit, DDDDDD - density.
If density == 0, CMOS-detect format assumed.
Fix attach code for correct work with unknown CMOS
floppy types.
Trick diskerr to handle new minor.
1.722M floppy in 1.44M drive popular format added.
E-mail: <sir@kiae.su>, <vak@zebub.msk.su>
added new /dev/wt entries for wt.c version 1.3
8) Some controllers support only 1024 block length.
Setting WT_BSIZE bit in device minor number turns on this mode.
Minor number structure:
0bfffuuu
Fields:
uuu - Unit number. It's possible to install
up to three tape controllers on the same machine,
using DRQs 1..3. Hence, unit number can lie
in range 0..2.
fff - Tape format number:
0 - /dev/rwt0 - default density (auto select)
1 - /dev/rwt0a - QIC 11 (obsolete)
2 - /dev/rwt0b - QIC 24 (60 megabytes)
3 - /dev/rwt0c - QIC 120 (120 megabytes)
4 - /dev/rwt0d - QIC 150 (150 megabytes)
5 - /dev/rwt0e - QIC 300 (300 megabytes?)
6 - /dev/rwt0f - QIC 600 (600 megabytes?)
b - Long block size flag. With this bit set,
the driver will perform all i/o operations
with the controller using 1024-byte
blocks, instead of 512 ones.
Some controllers need it (CMS for example).
If you Wangtek controller does not stream well,
you can try to use /dev/rWt0 device instead
of /dev/rwt0 (uncomment needed lines in /dev/MAKEDEV
to create it).
Block interface (writing blocks less than 2048 bytes) is not functioning
pwoperly. Use raw interface instead.
Thanks to all who helped to test it on the following hardware:
Controller Drive Volume Interface Thanks to
---------------------------------------------------------------------------
Archive SC-499 Archive 2150L 150 Meg QIC-02 KIAE
CMS? ? 150 Meg QIC-02 KIAE
Everex EV 831/833 ? ? QIC-36 Joergen Haegg
Wangtek ASSY Wangtek 60 Meg QIC-02 Ken Whedbee
Tecmar QT150i? Wangtek 5150EQ ? QIC-02? Marko Teiste
? Wangtek 5099EK 60 Meg QIC-36 Robert Shien
Archive SC400S ? 60 Meg ? Warren Toomey
from:
Sergey Ryzhkov, Serge Vakulenko
E-mail: <sir@kiae.su>, <vak@zebub.msk.su>
This is the streamer tape driver for 386bsd and FreeBSD, which
supports Wangtek and Archive compatible QIC-02/QIC-36 controllers.
It was developed as a replacement of the old Wangtek tape driver from CMU.
In comparison with the CMU driver, this version has the following enhancements:
1) Support for Archive SC402 and SC499 tape controllers added.
2) Support for up to three tape controllers on the same machine.
3) Support for BSD-style ioctls MTIOCGET, MTIOCTOP.
Mt command now works adequately with this driver.
2) Asynchronous REWIND and FSF operations, close() will not wait
until they finish. The next open() will wait for it instead.
4) Use of WTQICMD ioctl is limited to ERASE and RETENS operations.
This prevents the user from locking the tape driver by strange
tape operations.
5) Tape density switching added.
6) The status of the process, blocked on the tape operation,
is displayed at the WCHAN column of the `ps' command as:
wtread reading data from the tape
wtwrite writing data to the tape
wtrfm reading the tape marker
wtwfm writing the tape marker
wtrew rewinding the tape
wterase doing WTQICMD ERASE operation
wtretens doing WTQICMD RETENS operation
wtorew doing MTIOCTOP REW/OFFL operation
wtorfm doing MTIOCTOP FSF operation
wtowfm doing MTIOCTOP WEOF operation
7) It's possible to use the tape with "default density",
useful for devices which don't support density switching
or do automatic format determination.
8) Some controllers support only 1024 block length.
Setting WT_BSIZE bit in device minor number turns on this mode.
Minor number structure:
0bfffuuu
Fields:
uuu - Unit number. It's possible to install
up to three tape controllers on the same machine,
using DRQs 1..3. Hence, unit number can lie
in range 0..2.
fff - Tape format number:
0 - /dev/rwt0 - default density (auto select)
1 - /dev/rwt0a - QIC 11 (obsolete)
2 - /dev/rwt0b - QIC 24 (60 megabytes)
3 - /dev/rwt0c - QIC 120 (120 megabytes)
4 - /dev/rwt0d - QIC 150 (150 megabytes)
5 - /dev/rwt0e - QIC 300 (300 megabytes?)
6 - /dev/rwt0f - QIC 600 (600 megabytes?)
b - Long block size flag. With this bit set,
the driver will perform all i/o operations
with the controller using 1024-byte
blocks, instead of 512 ones.
Some controllers need it (CMS for example).
If you Wangtek controller does not stream well,
you can try to use /dev/rWt0 device instead
of /dev/rwt0 (uncomment needed lines in /dev/MAKEDEV
to create it).
Block interface (writing blocks less than 2048 bytes) is not functioning
pwoperly. Use raw interface instead.
Thanks to all who helped to test it on the following hardware:
Controller Drive Volume Interface Thanks to
---------------------------------------------------------------------------
Archive SC-499 Archive 2150L 150 Meg QIC-02 KIAE
CMS? ? 150 Meg QIC-02 KIAE
Everex EV 831/833 ? ? QIC-36 Joergen Haegg
Wangtek ASSY Wangtek 60 Meg QIC-02 Ken Whedbee
Tecmar QT150i? Wangtek 5150EQ ? QIC-02? Marko Teiste
? Wangtek 5099EK 60 Meg QIC-36 Robert Shien
Archive SC400S ? 60 Meg ? Warren Toomey
