[TUHS] 'Huge' file support removed from PWB1

Noel Chiappa jnc at mercury.lcs.mit.edu
Wed Mar 8 23:10:08 AEST 2023


In PWB1, support for 'huge' files appears to have been removed. If one
compares bmap() in PWB1'S subr.c with V6's, the "'huge' fetch of double
indirect block" code is gone. I guess PWB didn't need very large (> 8*256*512
= 1,048,576 bytes) files? I'm not sure what the _benefits_ of removing it
were, though - unless PWB was generating lots of files of between 7*256*512
and 8*256*512 bytes in length, and they wanted to avoid the overhead of the
double-indirect block? (The savings in code space are derisory - unlike in
LSX/MINI-UNIX.) Anyone know?

		Noel


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