Release Notes For Linux v0.97

This is the release notes for linux release v0.97 with format adjusted by removing/replacing tabs/spaces/new lines. This notes document can give us an understanding of the early development of the Linux kernel. The original ASCII formatted version is at the end of this post.

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Changes in 0.97:

• The VESA-support was removed. I’d be happy to put it back once it works on all hardware. Instead of the VESA-code, I finally put in the automatic SVGA setup patches. See the top-level Makefile.

• The IRQ code has solidified, and should work on all machines. Not all of the SCSI drivers use it yet, so I expect patches for that..

• Serial interrupts are handled slightly differently, and performance should be up. I’ve sent out a few alpha-releases, and testing seems to indicate that’s actually true this time. Reactions have ranged from “nice” to “wonderful” :-)

• The buffer-cache and memory management code has been edited quite a bit. ps/free etc programs that reads kernel memory directly no longer work, and even a recompilation won’t be enough. They actually need editing before they work.

  The buffer-cache now grows and shrinks dynamically depending on how much free memory there is. Shift+PrintScreen will give some memory statistics. (Ctrl+PrSc gives task-info, ALT+PrSc gives current register values).

  The mm code changes removed some race-conditions in the VM code, and I also tried to make the Out-of-swapspace error less severe (better thrashing-detection etc).

• The super-block code has been cleaned up. Especially the extended fs needs to be edited a bit to take advantage of the new setup, and I
  expect Remy Card will have a patch out eventually.

• include-files have been moved around some more: there are still some names that clash with the standard headers, but not many.

• Unswappable processes implemented: by default only ‘init’ is unswappable. This is a bit safer in low-memory conditions, as at least init won’t die due to low memory. I also made killing init impossible: if init doesn’t recognize a signal, it simply won’t get it. Some other changes (“while (1) fork();” won’t kill the machine for non-root users etc)

• The new SCSI drivers are in. These make the kernel noticeably bigger, but you can leave them out if you don’t want them.

• The floppy- and hd-drivers print out more debugging-info in case of errors: this might be irritating if you have hardware that works, but often gives soft-errors. On the other hand, some old debugging-info was removed – notably for user-level protection errors etc.

• Various minor fixes. I haven’t made cdiffs (and I haven’t gotten any requests for them, so I probably never will), but they would be pretty big.

Things that I didn’t have time for:

• I wanted to rewrite the tty drivers to be more “streams-like” (ie not an actual streams-implementation, but some of the ideas from streams). I never got around to it: there was simply too much else to do.

• I got a lot of patches, and some went in, others didn’t. If you think your patch was important, please re-send it relative to the new version.

I’d like comments on the new system: performance / clarity of code etc. 0.97 should correct all known bugs (at least the ones I know about), but I guess that’s just wishful thinking.

Note that the dynamic buffer-code also handles differently-sized buffers, but that the rest of the system (block device drivers,
filesystem code etc) cannot yet take advantage of this – there is still some coding needed.

Linus

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ASCII formatted “Release Notes For Linux v0.97”

Following is the original ASCII formatted version of the “Release Notes For Linux v0.97”.

Changes in 0.97:

 - The VESA-support was removed.  I'd be happy to put it back once it
   works on all hardware.  Instead of the VESA-code, I finally put in
   the automatic SVGA setup patches.  See the top-level Makefile. 

 - The IRQ code has solidified, and should work on all machines.  Not
   all of the SCSI drivers use it yet, so I expect patches for that.. 

 - Serial interrupts are handled slightly differently, and performance
   should be up.  I've sent out a few alpha-releases, and testing seems
   to indicate that's actually true this time.  Reactions have ranged
   from "nice" to "wonderful" :-)

 - The buffer-cache and memory management code has been edited quite a
   bit.  ps/free etc programs that reads kernel memory directly no
   longer work, and even a recompilation won't be enough.  They actually
   need editing before they work. 

   The buffer-cache now grows and shrinks dynamically depending on how
   much free memory there is.  Shift+PrintScreen will give some memory
   statistics.  (Ctrl+PrSc gives task-info, ALT+PrSc gives current
   register values). 

   The mm code changes removed some race-conditions in the VM code, and
   I also tried to make the Out-of-swapspace error less severe (better
   thrashing-detection etc).

 - The super-block code has been cleaned up.  Especially the extended fs
   needs to be edited a bit to take advantage of the new setup, and I
   expect Remy Card will have a patch out eventually. 

 - include-files have been moved around some more: there are still some
   names that clash with the standard headers, but not many. 

 - Unswappable processes implemented: by default only 'init' is
   unswappable.  This is a bit safer in low-memory conditions, as at
   least init won't die due to low memory.  I also made killing init
   impossible: if init doesn't recognize a signal, it simply won't get
   it.  Some other changes ("while (1) fork();" won't kill the machine
   for non-root users etc)

 - The new SCSI drivers are in.  These make the kernel noticeably
   bigger, but you can leave them out if you don't want them.

 - The floppy- and hd-drivers print out more debugging-info in case of
   errors: this might be irritating if you have hardware that works, but
   often gives soft-errors.  On the other hand, some old debugging-info
   was removed - notably for user-level protection errors etc. 

 - Various minor fixes.  I haven't made cdiffs (and I haven't gotten any
   requests for them, so I probably never will), but they would be
   pretty big. 

Things that I didn't have time for:

 - I wanted to rewrite the tty drivers to be more "streams-like" (ie not
   an actual streams-implementation, but some of the ideas from
   streams).  I never got around to it: there was simply too much else
   to do. 

 - I got a lot of patches, and some went in, others didn't.  If you
   think your patch was important, please re-send it relative to the new
   version.

I'd like comments on the new system: performance / clarity of code etc. 
0.97 should correct all known bugs (at least the ones I know about), but
I guess that's just wishful thinking. 

Note that the dynamic buffer-code also handles differently-sized
buffers, but that the rest of the system (block device drivers,
filesystem code etc) cannot yet take advantage of this - there is still
some coding needed. 

        Linus