Re: [9fans] Rstat needs three size fields?

["Douglas A. Gwyn" <DAGwyn@null.net>]

"rob pike, esq." wrote:
> >> 65536 is not a very big number in modern i/o systems.
> > Actally neither is 2^32.
> sometimes you become boyd-like in your contrarianism.
> 2^32 is a huge block size, even today, while 2^16 is not.

Perhaps I'm getting tired of engineers always tweaking
size fields up by a small amount every time they become
too small.  If you've had to deal with large IDE drives
on BIOSes more than a couple of years old you know what
I mean.  Ever-increasing-size FAT filesystem formats are
another example.  Utility software that is even slightly
old keeps turning out to be unable to cope with new
developments, due mainly to inadequate bits in existing
formats.  Why should there be such a drain on developer
resources to continually adapt to changing formats when
we could do it right for once and for all?

My rule of thumb used to be that whatever the biggest
size you can imagine for some object, allocate twice
as many bits to hold its size as seem sufficient.  But
even that approach doesn't survive for the decades that
ought to be attainable for things like disk descriptors.