Additional changes for 2.5

[unix-history] / sys / doc / Changes

Hello, Emacs, this is an -*- Indented-Text -*- file!

$Id: Changes,v 1.4 1994/04/14 18:02:13 wollman Exp $

This file is intended to keep track of important kernel and user
changes in FreeBSD between releases.  Entries are in reverse
chronological order; userids can be decoded with the chart at the end
of this file.

---------------
Since 1.1 BETA:
---------------

- I/O clustering is implemented for all block devices.  This should
  substantially improve the performance of disk drives which don't
  have write-behind caches, especially on IDE drives.  (dyson/davidg)

- Allow mbufs to point to other ``external'' objects than just
  clusters, and add in performance enhancements for NFS from Yuval
  Yarom.  (davidg)

- Yet more VM system improvements.  (dyson/davidg)
  o 4-MB systems should now spend substantially less time in the VM
    system.
  o General cleanup and some portability fixes.
  o A new system process is now responsible for keeping page
    statistics, rather than making the pagedaemon do it, which was
    getting impractical.  Performance is improved on small-memory
    machines.
  o Process resource usage counters are now properly updated for
    faults and swaps.

- Fixed bugs in truncating mapped files.  (dyson/davidg)

- A new version of the interrupt-handler glue code has been added, which
  is faster and architecturally cleaner than the previous version.  The
  beginnings of better profiling support have also been added.  (bde/davidg)

- This file moved from /sys/i386/doc to /sys/doc. (wollman)

- Bounce buffers have been implemented for ISA devices which use
  DMA (although not all devices can make use of it yet).  (davidg/dyson)

- The set*id() functions have been changed (wollman):
  o A significant security hole involving the POSIX saved uid and gid
    has been plugged.
  o The setreuid() and setregid() functions now never change the real
    ID, but rather only ensure that you will be able to change the
    EFFECTIVE ID back to what you specified as a real ID.  This change
    breaks the setruid() and setrgid() functions, which were a bad
    idea in a POSIX environment anyway.  Logic taken from 4.4BSD.
  o The SUGID process flag bit has been implemented as in 4.4, and the
    `ps' program modified to print it out.

- The scheduling algorithm has been changed to penalize
  processes that fork a lot, like `make', which should enhance
  interactive performance during such operations significantly.
  (davidg/dyson)

- MCLBYTES is now 4096, so each mbuf cluster is given a whole page, in
  preparation for page flipping.  (davidg/dyson)

- More VM system improvements (dyson/davidg):
  o Pre-faulting of initial pages on process startup and mmap (faster
    than starting and immediately taking a fault).
  o Even more efficient physical map (pmap) code.
  o Pageouts are now clustered, similar to pagein clustering in 1.1.
  o The pageout code is more efficient and keeps better statistics.
  o The procfs can now provide more information from the VM system.
  o Some pager bugs have been fixed.

- Improved IP checksum and bzero routines.  (bde/dyson)

- The Mitsumi CD-ROM driver is more careful about recognizing Ethernet
  cards as CD-ROMs.  (jkh)

- `struct tty's now allocated dynamically, and ring buffers can be
  deallocated. (guido)


---------------------------
Between 1.1 BETA and 1.0.2:
---------------------------

- QIC-40 and QIC-80 tapes are now supported, using the `ft' driver
  from Jim Babb.  (alm/nate)

- Improved lpt driver, should no longer lock up when lprm is done on
  an active job.  Fixed up the probe routine so that it works on most
  if not all printers now. (csgr/rgrimes)

- Substantial changes to system configuration; you MUST re-build
  `config' before attempting to build a 1.1 kernel.  (nate/martin)

- Improved the quality of the information given to the user when
  a fatal trap occurs.  (davidg)

- Added support in the if_ed driver for the WD8013W, WD8003W, and
  WD8003EB.  (davidg)

- Change to generic console code to eliminate console hangs with all 
  `pc' consoles.  (davidg)

- Upgrade to new version of syscons which handles the `hanging console'
  problem and adds some new features and code cleanup.  (nate)

- Various TCP bugs fixed - don't forward loopback packets; Nagel
  congestion avoidence - immediately ack small packets.  (davidg)

- TCP debugging code is now truly optional, thus reducing kernel size
  when it is disabled (the default).  (davidg)

- Because the `sio' FIFOs are now configurable, the `com' driver is no
  longer supported.  (team sighs with relief)

- Performance and stylistic improvements to the `sio' serial driver.
  Probe code now works somewhat better for oddball devices.  The 16550
  FIFO length is now configurable using `flags' in the config
  declaration.  (ache/bde)

- Performance improvements and complete implementation of POSIX VMIN
  and VTIME for the generic TTY code.  (ache/bde)

- Crash dumps on SCSI disks now work and are standard.  (rgrimes/davidg)

- QMAGIC is now the official default executable format.  (davidg)

- Network booting is now supported, as is booting from DOS.  (martin)

- Local LDTs are now supported for WINE (based on work by John Brezak).
  (hsu/davidg)

- DDB will now print symbolic arguments and line numbers in
  backtraces (from John Brezak).  (davidg)

- Added four pattern memory test to eliminate problems with buggy
  chipsets that incorrectly map memory, and to find problems with
  defective memory. The memory sizing code has been improved to
  further eliminate problems with buggy chipsets/BIOSs.  (davidg)

- USE_486_WRITE_PROTECT is now gone; the system will automatically
  detect 486 CPUs and behave accordingly.  (davidg)

- Added SysV IPC, messaging, and semaphore code by Danny Boulet.
  (hsu/davidg)

- Because of the VM system changes, Paul Kranenburg's process
  filesystem is now MANDATORY in order for `ps' and friends to be able
  to dig up process information which has been paged out.  (davidg)

- Substantial VM system improvements: (dyson/davidg)
	o FreeBSD once again works on 4-MB machines.
	o Maximum and default size limits set to reasonable values.
	o The user area is now in the process address space, and can
	  now be paged out along with the rest of the process.
	o Process page tables can now be paged out.
	o The physical map (pmap) module has been mostly rewritten for
	  efficiency, and is considerably faster than it used to be.
	o The pageout system now actually implements modified LRU.
	o Process RSS soft limits implemented. Hooks are in place for
	  RSS hard limits.
	o Pagers can now do multiple-page operations ("page fault
	  clustering"), and page fault read behind and read ahead
	  have been implemented to take advantage of this.
	o The vnode pager no longer drags pages through the buffer
	  cache, eliminating an expensive memory copy and flushing
	  of cached data.
	o When the system runs out of swap space, the faulting process
	  is killed off (with a message to syslog); the old code would
	  just deadlock.
	o Swap space allocation is much more efficient, and swap
	  striping actually works now. It's now possible for every
	  last block of swap space to be used before the systems runs
	  out.
	o The pagedaemon's algorithms are considerably improved, thus
	  reducing the amount of CPU time used by the pagedaemon.
	o All kernels MUST now load at virtual address 0xf010000, and
	  the lower 640k is reclaimed for system use. This removes
	  the 640K kernel size limit.
	o VM object cache size is now dynamic and a function of the
	  kernel `maxusers' parameter.
	o Memory in the I/O hole is explicitly marked non-cacheable.

- Added 3C509 driver written by Herb Peyerl. (ats/nate)

- Added a new `wd' driver which does a much better job of probing, handles
  stray interrupts better, and supports multiple controllers.  In addition
  this driver supports DOS partitions much better and conforms to ATA specs
  much better.  NB: configuration lines for this driver are different
  than those for pervious versions; see a GENERIC for details.
  (nate/bde/guido)

- Added support in the if_ed driver for the Toshiba ethernet cards.The
  support must be enabled with an "options TOSH_ETHER" in the config
  file. Done it this way, because I don't know how widespread the cards
  are. (ats)

- Added support in the if_ed driver for the SMC Ultra via patches from
  Glen Lowe. (davidg)

- Updated Mitsumi CD driver to work with FX models.  (jkh/Gary
  Clark II)

- Add extended formats set to floppy driver, improve autoconfiguration,
  add "fdformat" utility for floppy formatting.
  The format of floppy disk minor numbers has changed, thus
  necessitating a new `MAKEDEV fd'.  (ache/joerg/Serge Vakulenko)

- Add XNTPD to contrib section, and (un-compilable) kernel support for
  same to /sys/kern.  (wollman)

- Use linker-constructed sets to initialize certain system tables
  rather than manually enumerating all the options in the source files.
  This makes certain pseudo-devices and all image activators drop-in at
  link time, if desired.  (wollman)

- Added YP code from Theo Deraadt.  (paul/nate)

- Make all mandatory options ``standard''.  (wollman)

- Update `wt' driver to support more devices and controllers.  The
  driver will also auto-detect tape density on models which support
  it.  The structure of `wt' device minor numbers has changed;
  `MAKEDEV wt' must be run to create the new device nodes.

- Re-design execve() system call to allow for multiple ``image activators''
  which recognize and load various file formats.  Currently only
  a.out and interpreted formats are recognized.  (davidg)

- Provide the address of the faulting reference to signal handlers, to
  make life easier for smart garbage-collection algorithms.  (hsu)

- New, improved process tracing code from Sean Eric Fagan.  (davidg)

- Re-organize locore into several different source files according to
  function.  (davidg)

- On panic, don't reboot right away but give the user some time to
  abort the reboot or at least write down the panic message.  (davidg)

- Kernel timezone handling is now delegated to an external program,
  `adjkerntz'.  No more bogus summer time jumps.  (ache)

- Separate all IP-related variables that users might want to modify into
  netinet/in_var.c.  (wollman)

- New, redesigned SCSI system; should run faster and have fewer bugs.
  (julian)

- Make it possible to mmap(2) /dev/mem.  (julian)


-----------------------
Userids map as follows:
-----------------------
ache		Andrew Chernov
alm		Andrew Moore
ats		Andreas Schulz
chmr		Christoph Robitscho
csgr		Geoff Rehmet
davidg		David Greenman
dyson		John Dyson
guido		Guido van Rooij
hsu		Jeffrey Hsu
jkh		Jordan Hubbard
joerg		Joerg Wunsch
jtc		J.T. Conklin
ljo		L. Jonas Olson
martin		Martin Renters
nate		Nate Williams
paul		Paul Richards
proven		Chris Provenzano
rich		Rich Murphey
rls		Rob Shady
smace		Scott Mace
swallace	Steven Wallace
wollman		Garrett Wollman