[TUHS] the guy who brought up SVr4 on Sun machines

[Charles Anthony]

On Wed, Jan 11, 2017 at 10:07 AM, Noel Chiappa <jnc at mercury.lcs.mit.edu>
wrote:

>     > I wonder if >pdd ... was in any way any inspiration for /proc?
>
> That may have been a bit too cryptic. "pdd" ('process directory directory')
> was a top-level directory in the Multics filesystem which contained a
> directory for each process active in the system; each directory contained
> data
> (in segments - roughly, 'files', but Multics didn't have files because it
> was
> a single-level store system) associated with the process, such as its
> kernel-
> and user-mode (effectively - technically, ring-0 and ring-4) stacks, etc.
>
> So if a process was sitting in a system call, you could go into the right
> directory in >pdd and look at its kernel stack and see the sequence of
> procedure calls (with arguments) that had led it to the point where it
> blocked. Etc, etc.
>
>
'pdd' also contained temporary segments, ala mktemp:

r 11:33 0.092 1

cwd [pd]

r 11:33 0.086 3

ls
Segments = 21, Lengths = 0.
       0  !BBBKLDJkqPKWqL.area.linker
       0  stack_1
r w    0  archive_temp_.archive
rew    0  !BBBKLDJkqGGBMh.temp.0346
rew    0  !BBBKLDJkqGFKDc.temp.0345
rew    0  !BBBKLDJkqGDWMn.temp.0344
rew    0  !BBBKLDJkqGCfXX.temp.0343
rew    0  !BBBKLDJkqGBpDB.temp.0342
rew    0  !BBBKLDJkqGBCwg.temp.0341
rew    0  !BBBKLDJkqFzFDz.temp.0340
rew    0  !BBBKLDJkqFxMcW.temp.0337
rew    0  !BBBKLDJkpmxKqH.temp.0332
rew    0  !BBBKLDJkpmwMfz.temp.0331
r w    0  process_search_segment_.4
rew    0  !BBBKLDJknDXFNp.temp.0304
rew    0  !BBBKLDJknCfjfK.area.linker
rew    0  stack_4
re     0  pit
       0  pds
       0  kst
       0  dseg

r 11:33 0.214 0



-- Charles
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